1990 APPENDIX B. Definitions of Subject Characteristics
CONTENTS
POPULATION CHARACTERISTICS B-2
Ability to Speak English (See Language Spoken at Home and Ability
to Speak English)
Actual Hours Worked Last Week (See Employment Status)
Age B-2
American Indian Tribe (See Race)
Ancestry B-2
Carpooling (See Journey to Work)
Children Ever Born (See Fertility)
Citizenship B-4
Civilian Labor Force (See Employment Status)
Class of Worker (See Industry, Occupation, and Class of Worker)
Disability (See Mobility Limitation Status, see Self-Care Limitation
Status, see Work Disability Status)
Earnings in 1989 (See Income in 1989)
Educational Attainment B-4
Employment Status B-5
Families (See Household Type and Relationship)
Family Composition (See Household Type and Relationship)
Family Income in 1989 (See Income in 1989)
Family Size (See Household Type and Relationship)
Family Type (See Household Type and Relationship)
Farm Population (See Farm Residence under Housing Characteristics)
Fertility B-7
Foreign-Born Persons (See Place of Birth)
Foster Children (See Household Type and Relationship)
Group Quarters B-7
Hispanic Origin B-12
Household (See Household Type and Relationship)
Household Income in 1989 (See Income in 1989)
Household Language (See Language Spoken At Home and Ability
to Speak English)
Household Size (See Household Type and Relationship)
Household Type and Relationship B-13
Householder (See Household Type and Relationship)
Income Deficit (See Income in 1989)
Income in 1989 B-15
Income Type in 1989 (See Income in 1989)
Industry, Occupation, and Class of Worker B-19
Institutionalized Persons (See Group Quarters)
Journey to Work B-21
Labor Force Status (See Employment Status)
Language Spoken at Home and Ability to Speak English B-23
Linguistic Isolation (See Language Spoken at Home and Ability
to Speak English)
Marital Status B-25
Married Couples (See Marital Status)
Means of Transportation to Work (See Journey to Work)
Migration (See Residence in 1985)
Mobility Limitation Status B-26
Nativity (See Place of Birth)
Noninstitutionalized Group Quarters (See Group Quarters)
Occupation (See Industry, Occupation, and Class of Worker)
Own Children (See Household Type and Relationship)
Per Capita Income (See Income in 1989)
Period of Military Service (See Veteran Status)
Persons in Family (See Household Type and Relationship)
Persons in Households (See Household Type and Relationship)
Place of Birth B-26
Place of Work (See Journey to Work)
Poverty Status in 1989 B-27
Presence of Children (See Household Type and Relationship)
Private Vehicle Occupancy (See Journey to Work)
Race B-28
Reference Week B-31
Related Children (See Household Type and Relationship)
Residence in 1985 B-32
School Enrollment and Labor Force Status B-33
School Enrollment and Type of School B-33
Self-Care Limitation Status B-34
Sex B-34
Spanish Origin (See Hispanic Origin)
Stepfamily (See Household Type and Relationship)
Subfamily (See Household Type and Relationship)
Time Leaving Home to Go to Work (See Journey to Work)
Travel Time to Work (See Journey to Work)
Type of School (See School Enrollment and Type of School)
Usual Hours Worked Per Week Worked in 1989 (See Work Status in 1989)
Veteran Status B-34
Weeks Worked in 1989 (Work Status in 1989)
Work Disability Status B-35
Work Status in 1989 B-35
Worker (See Employment Status, see Industry, Occupation, and Class
of Worker, see Journey to Work, see Work Status in 1989)
Workers in Family in 1989 (See Work Status in 1989)
Year of Entry B-36
Years of Military Service (See Veteran Status)
HOUSING CHARACTERISTICS B-36
Acreage B-37
Age of Structure (See Year Structure Built)
Agricultural Sales B-38
Bedrooms B-38
Boarded-Up Status B-38
Business on Property B-38
Condominium Fee B-39
Condominium Status B-39
Congregate Housing (See Meals Included in Rent)
Contract Rent B-39
Crop Sales (See Agricultural Sales)
Duration of Vacancy B-40
Farm Residence B-40
Gross Rent B-40
Gross Rent as a Percentage of Household Income in 1989 B-41
Homeowner Vacancy Rate (See Vacancy Status)
House Heating Fuel B-41
Housing Units (See Living Quarters)
Insurance for Fire, Hazard, and Flood B-41
Kitchen Facilities B-41
Living Quarters B-36
Meals Included in Rent B-41
Mobile Home Costs B-42
Months Vacant (See Duration of Vacancy)
Mortgage Payment B-42
Mortgage Status B-42
Occupied Housing Units (See Living Quarters)
Owner-Occupied Housing Units (See Tenure)
Persons in Unit B-43
Persons Per Room B-43
Plumbing Facilities B-43
Poverty Status of Households in 1989 B-43
Real Estate Taxes B-43
Rental Vacancy Rate (See Vacancy Status)
Renter-Occupied Housing Units (See Tenure)
Rooms B-44
Second or Junior Mortgage Payment B-44
Selected Monthly Owner Costs B-44
Selected Monthly Owner Costs as a Percentage of Household
Income in 1989 B-45
Sewage Disposal B-45
Source of Water B-45
Telephone in Housing Unit B-45
Tenure B-46
Type of Structure (See Units in Structure)
Units in Structure B-46
Usual Home Elsewhere B-47
Utilities B-47
Vacancy Status B-47
Vacant Housing Units (See Living Quarters)
Value B-48
Vehicles Available B-48
Year Householder Moved Into Unit B-49
Year Structure Built B-49
DERIVED MEASURES B-49
Interpolation B-49
Mean B-49
Median B-49
Percentages, Rates, and Ratios B-50
Quartile B-50
POPULATION CHARACTERISTICS
AGE--The data on age were derived from answers to questionnaire
item 5, which was asked of all persons. The age classification is based
on the age of the person in complete years as of April 1, 1990. The age
response in question 5a was used normally to represent a person's age.
However, when the age response was unacceptable or unavailable, a
person's age was derived from an acceptable year-of-birth response in
question 5b.
Data on age are used to determine the applicability of other questions
for a person and to classify other characteristics in census
tabulations. Age data are needed to interpret most social and economic
characteristics used to plan and examine many programs and policies.
Therefore, age is tabulated by single years of age and by many
different groupings, such as 5-year age groups.
Some tabulations are shown by the age of the householder. These data
were derived from the age responses for each householder. (For more
information on householder, see the discussion under "Household Type
and Relationship.")
Median Age--This measure divides the age distribution into two equal parts:
one-half of the cases falling below the median value and one-half above
the value. Generally, median age is computed on the basis of more
detailed age intervals than are shown in some census publications;
thus, a median based on a less detailed distribution may differ
slightly from a corresponding median for the same population based on a
more detailed distribution. (For more information on medians, see the
discussion under "Derived Measures.")
Limitation of the Data--Counts in 1970 and 1980 for persons 100 years old
and over were substantially overstated. Improvements were made in the
questionnaire design, in the allocation procedures, and to the respondent
instruction guide to attempt to minimize this problem for the 1990 census.
Review of detailed 1990 census information indicated that respondents
tended to provide their age as of the date of completion of the
questionnaire, not their age as of April 1, 1990. In addition, there
may have been a tendency for respondents to round their age up if they
were close to having a birthday. It is likely that approximately 10
percent of persons in most age groups are actually 1 year younger. For
most single years of age, the misstatements are largely offsetting. The
problem is most pronounced at age 0 because persons lost to age 1 may not
have been fully offset by the inclusion of babies born after April 1, 1990,
and because there may have been more rounding up to age 1 to avoid
reporting age as 0 years. (Age in complete months was not collected for
infants under age 1.)
The reporting of age 1 year older than age on April 1, 1990, is likely
to have been greater in areas where the census data were collected
later in 1990. The magnitude of this problem was much less in the three
previous censuses where age was typically derived from respondent data
on year of birth and quarter of birth. (For more information on the
design of the age question, see the section below that discusses
"Comparability.")
Comparability--Age data have been collected in every census. For the first
time since 1950, the 1990 data are not available by quarter year of age.
This change was made so that coded information could be obtained for both
age and year of birth. In each census since 1940, the age of a person
was assigned when it was not reported. In censuses before 1940, with
the exception of 1880, persons of unknown age were shown as a separate
category. Since 1960, assignment of unknown age has been performed by a
general procedure described as "imputation." The specific
procedures for imputing age have been different in each census. (For
more information on imputation, see Appendix C, Accuracy of the Data.)
ANCESTRY--The data on ancestry were derived from answers to
questionnaire item 13, which was asked of a sample of persons. The
question was based on self-identification; the data on ancestry
represent self-classification by people according to the ancestry
group(s) with which they most closely identify. Ancestry refers to a
person's ethnic origin or descent, "roots," or heritage or the
place of birth of the person or the person's parents or ancestors
before their arrival in the United States. Some ethnic identities, such
as "Egyptian" or "Polish" can be traced to geographic areas
outside the United States, while other ethnicities such as
"Pennsylvania Dutch" or "Cajun" evolved in the United
States.
The intent of the ancestry question was not to measure the degree of
attachment the respondent had to a particular ethnicity. For example, a
response of "Irish" might reflect total involvement in an "Irish" community
or only a memory of ancestors several generations removed from the
individual.
The Census Bureau coded the responses through an automated review,
edit, and coding operation. The open-ended write-in ancestry item was coded
by subject-matter specialists into a numeric representation using a code
list containing over 1,000 categories. The 1990 code list reflects the
results of the Census Bureau's own research and consultations with many
ethnic experts. Many decisions were made to determine the classification of
responses. These decisions affected the grouping of the tabulated data. For
example, the "Assyrian" category includes both responses of "Assyrian"
and "Chaldean."
The ancestry question allowed respondents to report one or more
ancestry groups. While a large number of respondents listed a single
ancestry, the majority of answers included more than one ethnic entry.
Generally, only the first two responses reported were coded in 1990. If
a response was in terms of a dual ancestry, for example, Irish-English,
the person was assigned two codes, in this case one for Irish and
another for English.
However, in certain cases, multiple responses such as "French
Canadian," "Scotch-Irish," "Greek Cypriote," and "Black Dutch" were
assigned a single code reflecting their status as unique groups. If a
person reported one of these unique groups in addition to another group,
for example, "Scotch-Irish English," resulting in three terms, that person
received one code for the unique group ("Scotch-Irish") and another one for
the remaining group ("English"). If a person reported "English Irish
French," only English and Irish were coded. Certain combinations of
ancestries where the ancestry group is a part of another, such as "German-
Bavarian," the responses were coded as a single ancestry using the smaller
group ("Bavarian"). Also, responses such as "Polish-American" or
"Italian-American" were coded and tabulated as a single entry
("Polish" or "Italian").
The Census Bureau accepted "American" as a unique ethnicity if it
was given alone, with an ambiguous response, or with State names. If
the respondent listed any other ethnic identity such as "Italian
American," generally the "American" portion of the response
was not coded. However, distinct groups such as "American
Indian," "Mexican American," and "African American" were
coded and identified separately because they represented groups who
considered themselves different from those who reported as
"Indian," "Mexican," or "African," respectively.
In all tabulations, when respondents provided an unacceptable ethnic
identity (for example, an uncodeable or unintelligible response such as
"multi-national," "adopted," or "I have no idea"), the answer was included
in "Ancestry not reported."
The tabulations on ancestry are presented using two types of data
presentations--one used total persons as the base, and the other used
total responses as the base. The following are categories shown in the
two data presentations:
Presentation Based on Persons:
Single Ancestries Reported--Includes all persons who reported only one
ethnic group. Included in this category are persons with multiple-term
responses such as "Scotch-Irish" who are assigned a single code.
Multiple Ancestries Reported--Includes all persons who reported more than
one group and were assigned two ancestry codes.
Ancestry Unclassified--Includes all persons who provided a response that
could not be assigned an ancestry code because they provided nonsensical
entries or religious responses.
Presentations Based on Responses:
Total Ancestries Reported--Includes the total number of ancestries
reported and coded. If a person reported a multiple ancestry such as
"French Danish," that response was counted twice in the tabulations--once
in the "French" category and again in the "Danish" category. Thus, the
sum of the counts in this type of presentation is not the total
population but the total of all responses.
First Ancestry Reported--Includes the first response of all persons who
reported at least one codeable entry. For example, in this category, the
count for "Danish" would include all those who reported only Danish and
those who reported Danish first and then some other group.
Second Ancestry Reported--Includes the second response of all persons who
reported a multiple ancestry. Thus, the count for "Danish" in this
category includes all persons who reported Danish as the second response,
regardless of the first response provided.
The Census Bureau identified hundreds of ethnic groups in the 1990
census. However, it was impossible to show information for every group
in all census tabulations because of space constraints. Publications
such as the 1990 CP-2, Social and Economic Characteristics
and the 1990 CPH-3, Population and Housing Characteristics
for Census Tracts and Block Numbering Areas reports show a limited
number of groups based on the number reported and the advice received
from experts. A more complete distribution of groups is presented in
the 1990 Summary Tape File 4, supplementary reports, and a special
subject report on ancestry. In addition, groups identified specifically
in the questions on race and Hispanic origin (for example, Japanese,
Laotian, Mexican, Cuban, and Spaniard), in general, are not shown
separately in ancestry tabulations.
Limitation of the Data--Although some experts consider religious
affiliation a component of ethnic identity, the ancestry question was not
designed to collect any information concerning religion. The Bureau of the
Census is prohibited from collecting information on religion. Thus, if a
religion was given as an answer to the ancestry question, it was coded as
an "Other" response.
Comparability--A question on ancestry was first asked in
the 1980 census. Although there were no comparable data prior to the
1980 census, related information on ethnicity was collected through
questions on parental birthplace, own birthplace, and language which
were included in previous censuses. Unlike other census questions,
there was no imputation for nonresponse to the ancestry question.
In 1990, respondents were allowed to report more than one ancestry
group; however, only the first two ancestry groups identified were
coded. In 1980, the Census Bureau attempted to code a third ancestry
for selected triple-ancestry responses.
New categories such as "Arab" and "West Indian" were added to the 1990
question to meet important data needs. The "West Indian" category excluded
"Hispanic" groups such as "Puerto Rican" and "Cuban" that were identified
primarily through the question on Hispanic origin. In 1990, the ancestry
group, "American" is recognized and tabulated as a unique ethnicity. In
1980, "American" was tabulated but included under the category "Ancestry
not specified."
A major improvement in the 1990 census was the use of an automated
coding system for ancestry responses. The automated coding system used
in the 1990 census greatly reduced the potential for error associated
with a clerical review. Specialists with a thorough knowledge of the
subject matter reviewed, edited, coded, and resolved inconsistent or
incomplete responses.
CITIZENSHIP--The data on citizenship were derived from answers to
questionnaire item 9, which was asked of a sample of persons.
Citizen--Persons who indicated that they were native-born and foreign-born
persons who indicated that they have become naturalized. (For more
information on native and foreign born, see the discussion under "Place of
Birth.")
There are four categories of citizenship: (1) born in the United
States, (2) born in Puerto Rico, Guam, the Virgin Islands of the United
States, or the Commonwealth of the Northern Mariana Islands, (3) born
abroad of American parents, and (4) citizen by naturalization.
Naturalized Citizen--Foreign-born persons who had completed the
naturalization process at the time of the census and upon whom the rights
of citizenship had been conferred.
Not a Citizen--Foreign-born persons who were not citizens, including
persons who had begun but not completed the naturalization process at the
time of the census.
Limitation of the Data--Evaluation studies completed after previous
censuses indicated that some persons may have reported themselves as
citizens although they had not yet attained the status.
Comparability--Similar questions on citizenship were asked in the censuses
of 1820, 1830, 1870, 1890 through 1950, 1970, and 1980. The 1980 question
was asked of a sample of the foreign-born population. In 1990, both native
and foreign-born persons who received the long-form questionnaire were
asked to respond to the citizenship question.
EDUCATIONAL ATTAINMENT--Data on educational attainment were derived from
answers to questionnaire item 12, which was asked of a sample of persons.
Data are tabulated as attainment for persons 15 years old and over. Persons
are classified according to the highest level of school completed or the
highest degree received. The question included instructions to report the
level of the previous grade attended or the highest degree received for
persons currently enrolled in school. The question included response
categories which allowed persons to report completing the 12th grade
without receiving a high school diploma, and which instructed respondents
to report as "high school graduate(s)"--persons who received either a high
school diploma or the equivalent, for example, passed the Test of General
Educational Development (G.E.D.), and did not attend college. (On the
Military Census Report questionnaire, the lowest response category was
"Less than 9th grade.")
Instructions included in the 1990 respondent instruction guide, which
was mailed with the census questionnaire, further specified that
schooling completed in foreign or ungraded school systems should be
reported as the equivalent level of schooling in the regular American
system; that vocational certificates or diplomas from vocational,
trade, or business schools or colleges were not to be reported unless
they were college level degrees; and that honorary degrees were not to
be reported. The instructions gave "medicine, dentistry,
chiropractic, optometry, osteopathic medicine, pharmacy, podiatry,
veterinary medicine, law, and theology" as examples of professional
school degrees, and specifically excluded "barber school,
cosmetology, or other training for a specific trade" from the
professional school category. The order in which they were listed
suggested that doctorate degrees were "higher" than professional
school degrees, which were "higher" than master's degrees.
Persons who did not report educational attainment were assigned the
attainment of a person of the same age, race or Spanish origin, and sex
who resided in the same or a nearby area. Persons who filled more than
one circle were edited to the highest level or degree reported.
High School Graduate or Higher--Includes persons whose highest degree was a
high school diploma or its equivalent, persons who attended college or
professional school, and persons who received a college, university, or
professional degree. Persons who reported completing the 12th grade but not
receiving a diploma are not included.
Not Enrolled, Not High School Graduate--Includes persons of compulsory
school attendance age or above who were not enrolled in school and were not
high school graduates; these persons may be taken to be "high school
dropouts." There is no restriction on when they "dropped out" of school,
and they may have never attended high school.
In prior censuses, "Median school years completed" was used as
a summary measure of educational attainment. In 1990, the median can
only be calculated for groups of which less than half the members have
attended college. "Percent high school graduate or higher" and
"Percent bachelor's degree or higher" are summary measures which
can be calculated from the present data and offer quite readily
interpretable measures of differences between population subgroups. To
make comparisons over time, "Percent high school graduate or
higher" can be calculated and "Percent bachelor's degree or
higher" can be approximated with data from previous censuses.
Comparability--From 1840 to 1930, the census measured educational
attainment by means of a basic literacy question. In 1940, a single
question was asked on highest grade of school completed. In the censuses of
1950 through 1980, a two-part question asking highest grade of school
attended and whether that grade was finished was used to construct highest
grade or year of school completed. For persons who have not attended
college, the response categories in the 1990 educational attainment
question should produce data which are comparable to data on highest grade
completed from earlier censuses.
The response categories for persons who have attended college were
modified from earlier censuses because there was some ambiguity in
interpreting responses in terms of the number of years of college
completed. For instance, it was not clear whether "completed the
fourth year of college," "completed the senior year of
college," and "college graduate" were synonymous. Research
conducted shortly before the census suggests that these terms were more
distinct in 1990 than in earlier decades, and this change may have
threatened the ability to estimate the number of "college
graduates" from the number of persons reported as having completed
the fourth or a higher year of college. It was even more difficult to
make inferences about post-baccalaureate degrees and "Associate"
degrees from highest year of college completed. Thus, comparisons of
post-secondary educational attainment in this and earlier censuses
should be made with great caution.
In the 1960 and subsequent censuses, persons for whom educational
attainment was not reported were assigned the same attainment level as
a similar person whose residence was in the same or a nearby area. In
the 1940 and 1950 censuses, persons for whom educational attainment was
not reported were not allocated.
EMPLOYMENT STATUS--The data on employment status were derived from answers
to questionnaire items 21, 25, and 26, which were asked of a sample of
persons. The series of questions on employment status was asked of all
persons 15 years old and over and was designed to identify, in this
sequence: (1) persons who worked at any time during the reference week; (2)
persons who did not work during the reference week but who had jobs or
businesses from which they were temporarily absent (excluding layoff); (3)
persons on layoff; and (4) persons who did not work during the reference
week, but who were looking for work during the last four weeks and were
available for work during the reference week. (For more information, see
the discussion under "Reference Week.")
The employment status data shown in this and other 1990 census
tabulations relate to persons 16 years old and over. Some tabulations
showing employment status, however, include persons 15 years old. By
definition, these persons are classified as "Not in Labor
Force.". In the 1940, 1950, and 1960 censuses, employment status
data were presented for persons 14 years old and over. The change in
the universe was made in 1970 to agree with the official measurement of
the labor force as revised in January 1967 by the U.S. Department of
Labor. The 1970 census was the last to show employment data for persons
14 and 15 years old.
Employed--All civilians 16 years old and over who were either (1) "at
work"--those who did any work at all during the reference week as
paid employees, worked in their own business or profession, worked on
their own farm, or worked 15 hours or more as unpaid workers on a
family farm or in a family business; or (2) were "with a job but not
at work"--those who did not work during the reference week but had
jobs or businesses from which they were temporarily absent due to
illness, bad weather, industrial dispute, vacation, or other personal
reasons. Excluded from the employed are persons whose only activity
consisted of work around the house or unpaid volunteer work for
religious, charitable, and similar organizations; also excluded are
persons on active duty in the United States Armed Forces.
Unemployed--All civilians 16 years old and over are classified as
unemployed if they (1) were neither "at work" nor "with a job but not at
work" during the reference week, and (2) were looking for work
during the last 4 weeks, and (3) were available to accept a job. Also
included as unemployed are civilians who did not work at all during the
reference week and were waiting to be called back to a job from which
they had been laid off. Examples of job seeking activities are:
Registering at a public or private employment office
Meeting with prospective employers
Investigating possibilities for starting a professional
practice or opening a business
Placing or answering advertisements
Writing letters of application
Being on a union or professional register
Civilian Labor Force--Consists of persons classified as employed or
unemployed in accordance with the criteria described above.
Experienced Unemployed--These are unemployed persons who have worked at any
time in the past.
Experienced Civilian Labor Force--Consists of the employed and the
experienced unemployed.
Labor Force--All persons classified in the civilian labor force plus
members of the U.S. Armed Forces (persons on active duty with the United
States Army, Air Force, Navy, Marine Corps, or Coast Guard).
Not in Labor Force--All persons 16 years old and over who are not
classified as members of the labor force. This category consists mainly of
students, housewives, retired workers, seasonal workers enumerated in an
off season who were not looking for work, institutionalized persons, and
persons doing only incidental unpaid family work (less than 15 hours
during the reference week).
Worker--This term appears in connection with several subjects: journey-to-
work items, class of worker, weeks worked in 1989, and number of workers in
family in 1989. Its meaning varies and, therefore, should be determined
in each case by referring to the definition of the subject in which it
appears.
Actual Hours Worked Last Week--All persons who reported working during the
reference week were asked to report in questionnaire item 21b the number of
hours that they worked. The statistics on hours worked pertain to the
number of hours actually worked at all jobs, and do not necessarily reflect
the number of hours typically or usually worked or the scheduled number of
hours. The concept of "actual hours" differs from that of "usual
hours" described below. The number of persons who worked only a
small number of hours is probably understated since such persons
sometimes consider themselves as not working. Respondents were asked to
include overtime or extra hours worked, but to exclude lunch hours,
sick leave, and vacation leave.
Limitation of the Data--The census may understate the number of employed
persons because persons who have irregular, casual, or unstructured jobs
sometimes report themselves as not working. The number of employed persons
"at work" is probably overstated in the census (and conversely, the
number of employed "with a job, but not at work" is understated)
since some persons on vacation or sick leave erroneously reported
themselves as working. This problem has no effect on the total number
of employed persons. The reference week for the employment data is not
the same for all persons. Since persons can change their employment
status from one week to another, the lack of a uniform reference week
may mean that the employment data do not reflect the reality of the
employment situation of any given week. (For more information, see the
discussion under "Reference Week.")
Comparability--The questionnaire items and employment status concepts for
the 1990 census are essentially the same as those used in the 1980 and 1970
censuses. However, these concepts differ in many respects from those
associated with the 1950 and 1960 censuses.
Since employment data from the census are obtained from respondents in
households, they differ from statistics based on reports from
individual business establishments, farm enterprises, and certain
government programs. Persons employed at more than one job are counted
only once in the census and are classified according to the job at
which they worked the greatest number of hours during the reference
week. In statistics based on reports from business and farm
establishments, persons who work for more than one establishment may be
counted more than once. Moreover, some tabulations may exclude private
household workers, unpaid family workers, and self-employed persons,
but may include workers less than 16 years of age.
An additional difference in the data arises from the fact that persons
who had a job but were not at work are included with the employed in
the census statistics, whereas many of these persons are likely to be
excluded from employment figures based on establishment payroll
reports. Furthermore, the employment status data in census tabulations
include persons on the basis of place of residence regardless of where
they work, whereas establishment data report persons at their place of
work regardless of where they live. This latter consideration is
particularly significant when comparing data for workers who commute
between areas.
Census data on actual hours worked during the reference week may differ
from data from other sources. The census measures hours actually
worked, whereas some surveys measure hours paid for by employers.
Comparability of census actual hours worked data may also be affected
by the nature of the reference week (see "Reference Week").
For several reasons, the unemployment figures of the Census Bureau are
not comparable with published figures on unemployment compensation
claims. For example, figures on unemployment compensation claims
exclude persons who have exhausted their benefit rights, new workers
who have not earned rights to unemployment insurance, and persons
losing jobs not covered by unemployment insurance systems (including
some workers in agriculture, domestic services, and religious
organizations, and self-employed and unpaid family workers). In
addition, the qualifications for drawing unemployment compensation
differ from the definition of unemployment used by the Census Bureau.
Persons working only a few hours during the week and persons with a job
but not at work are sometimes eligible for unemployment compensation
but are classified as "Employed" in the census. Differences in
the geographical distribution of unemployment data arise because the
place where claims are filed may not necessarily be the same as the
place of residence of the unemployed worker.
The figures on employment status from the decennial census are
generally comparable with similar data collected in the Current
Population Survey. However, some difference may exist because of
variations in enumeration and processing techniques.
FERTILITY--The data on fertility (also referred to as "children ever born")
were derived from answers to questionnaire item 20, which was asked of a
sample of women 15 years old and over regardless of marital status.
Stillbirths, stepchildren, and adopted children were excluded from the
number of children ever born. Ever-married women were instructed to include
all children born to them before and during their most recent marriage,
children no longer living, and children away from home, as well as children
who were still living in the home. Never-married women were instructed to
include all children born to them.
Data are most frequently presented in terms of the aggregate number of
children ever born to women in the specified category and in terms of
the rate per 1,000 women. For purposes of calculating the aggregate,
the open-ended response category, "12 or more" is assigned a value of 13.
Limitation of the Data--Although the data are assumed to be less complete
for out-of-wedlock births than for births occurring within marriage,
comparisons of 1980 census data on the fertility of single women with other
census sources and administrative records indicate that no significant
differences were found between different data sources; that is, 1980 census
data on children ever born to single women were complete with no
significant understatements of childbearing.
Comparability--The wording of the question on children ever born was the
same in 1990 as in 1980. In 1970, however, the question on children ever
born was asked of all ever-married women but only of never-married women
who received self-administered questionnaires. Therefore, rates and numbers
of children ever born to single women in 1970 may be understated. Data
presented for children ever born to ever-married women are comparable
for the 1990 census and all previous censuses containing this question.
GROUP QUARTERS--All persons not living in households are classified by the
Census Bureau as living in group quarters. Two general categories of
persons in group quarters are recognized:
(1) institutionalized persons and
(2) other persons in group quarters (also referred to as
"noninstitutional group quarters").
Institutionalized Persons--Includes persons under formally authorized,
supervised care or custody in institutions at the time of enumeration. Such
persons are classified as "patients or inmates" of an institution
regardless of the availability of nursing or medical care, the length of
stay, or the number of persons in the institution. Generally,
institutionalized persons are restricted to the institutional buildings and
grounds (or must have passes or escorts to leave) and thus have limited
interaction with the surrounding community. Also, they are generally under
the care of trained staff who have responsibility for their safekeeping and
supervision.
Type of Institution--The type of institution was determined as part of
census enumeration activities. For institutions which specialize in only
one specific type of service, all patients or inmates were given the same
classification. For institutions which had multiple types of major
services (usually general hospitals and Veterans' Administration
hospitals), patients were classified according to selected types of wards.
For example, in psychiatric wards of hospitals, patients were classified in
"mental (psychiatric) hospitals"; in hospital wards for persons with
chronic diseases, patients were classified in "hospitals for the
chronically ill." Each patient or inmate was classified in only one type of
institution. Institutions include the following types:
Correctional Institutions--Includes prisons, Federal
detention centers, military stockades and jails, police lockups,
halfway houses, local jails, and other confinement facilities,
including work farms.
Prisons--Where persons convicted of crimes serve their
sentences. In some census products, the prisons are classified by two
types of control:
(1) "Federal" (operated by the Bureau of Prisons of the Department
of Justice) and (2) "State." Residents who are criminally insane were
classified on the basis of where they resided at the time of
enumeration: (1) in institutions (or hospital wards) operated by
departments of correction or similar agencies; or
(2) in institutions operated by departments of mental health or
similar agencies.
Federal Detention Centers--Operated by the Immigration
and Naturalization Service (INS) and the Bureau of Prisons. These
facilities include detention centers used by the Park Police; Bureau of
Indian Affairs Detention Centers; INS Centers, such as the INS Federal
Alien Detention Facility; INS Processing Centers; and INS Contract
Detention Centers used to detain aliens under exclusion or deportation
proceedings, as well as those aliens who have not been placed into
proceedings, such as custodial required departures; and INS Detention
Centers operated within local jails, and State and Federal prisons.
Military Stockades, Jails--Operated by military police
and used to hold persons awaiting trial or convicted of violating
military laws.
Local Jails and Other Confinement Facilities--Includes
facilities operated by counties and cities that primarily hold persons
beyond arraignment, usually for more than 48 hours. Also included in
this category are work farms used to hold persons awaiting trial or
serving time on relatively short sentences and jails run by private
businesses under contract for local governments (but not by
State governments).
Police Lockups--Temporary-holding facilities operated
by county and city police that hold persons for 48 hours or less only
if they have not been formally charged in court.
Halfway Houses--Operated for correctional purposes and include
probation and restitution centers, pre- release centers, and
community-residential centers.
Other Types of Correctional Institutions--Privately
operated correctional facilities and correctional facilities
specifically for alcohol/drug abuse.
Nursing Homes--Comprises a heterogeneous group of places. The majority
of patients are elderly, although persons who require nursing care
because of chronic physical conditions may be found in these homes
regardless of their age. Included in this category are skilled-nursing
facilities, intermediate-care facilities, long-term care rooms in wards
or buildings on the grounds of hospitals, or long-term care
rooms/nursing wings in congregate housing facilities.
Also included are nursing, convalescent, and rest homes, such as
soldiers', sailors', veterans', and fraternal or religious homes for
the aged, with or without nursing care. In some census products,
nursing homes are classified by type of ownership as "Federal,"
"State," "Private not-for-profit," and "Private for
profit."
Mental (Psychiatric) Hospitals--Includes hospitals or
wards for the criminally insane not operated by a prison, and
psychiatric wards of general hospitals and veterans' hospitals.
Patients receive supervised medical/nursing care from formally-trained
staff. In some census products, mental hospitals are classified by type
of ownership as "Federal," "State or local,"
"Private," and "Ownership not known."
Hospitals for Chronically Ill--Includes hospitals for
patients who require long-term care, including those in military
hospitals and wards for the chronically ill located on military bases;
or other hospitals or wards for the chronically ill, which include
tuberculosis hospitals or wards, wards in general and Veterans'
Administration hospitals for the chronically ill, neurological wards,
hospices, wards for patients with Hansen's Disease (leprosy) and other
incurable diseases, and other unspecified wards for the chronically
ill. Patients who had no usual home elsewhere were enumerated as part
of the institutional population in the wards of general and military
hospitals. Most hospital patients are at the hospital temporarily and
were enumerated at their usual place of residence. (For more
information, see "Wards in General and Military Hospitals for
Patients Who Have No Usual Home Elsewhere.")
Schools, Hospitals, or Wards for the Mentally Retarded--Includes those
institutions such as wards in hospitals for the mentally retarded, and
intermediate-care facilities for the mentally retarded that provide
supervised medical/nursing care from formally-trained staff. In some
census products, this category is classified by type of ownership as
"Federal," "State or local," "Private," and "Ownership not known."
Schools, Hospitals, or Wards for the Physically Handicapped--Includes
three types of institutions: institutions for the blind, those for the
deaf, and orthopedic wards and institutions for the physically
handicapped. Institutions for persons with speech problems are
classified with "institutions for the deaf." The category "orthopedic
wards and institutions for the physically handicapped" includes those
institutions providing relatively long-term care to accident victims,
and to persons with polio, cerebral palsy, and muscular dystrophy. In
some census products, this category is classified by type of ownership
as "Public," "Private," and "Ownership not known."
Hospitals, and Wards for Drug/Alcohol Abuse--Includes hospitals, and
hospital wards in psychiatric and general hospitals. These facilities
are equipped medically and designed for the diagnosis and treatment of
medical or psychiatric illnesses associated with alcohol or drug abuse.
Patients receive supervised medical care from formally-trained staff.
Wards in General and Military Hospitals for Patients Who
Have No Usual Home Elsewhere--Includes maternity, neonatal,
pediatric (including wards for boarder babies), military, and surgical
wards of hospitals, and wards for persons with infectious diseases.
Juvenile Institutions--Includes homes, schools, and other institutions
providing care for children (short- or long-term care). Juvenile
institutions include the following types:
Homes for Abused, Dependent, and Neglected Children--Includes
orphanages and other institutions which provide long-term care
(usually more than 30 days) for children. This category
is classified in some census products by type of ownership as
"Public" and "Private."
Residential Treatment Centers--Includes those institutions which
primarily serve children who, by clinical diagnosis, are moderately
or seriously disturbed emotionally. Also, these institutions provide
long-term treatment services, usually supervised or directed by a
psychiatrist.
Training Schools for Juvenile Delinquents--Includes residential
training schools or homes, and industrial schools, camps, or farms for
juvenile delinquents.
Public Training Schools for Juvenile Delinquents--Usually operated by
a State agency (for example, department of welfare, corrections, or a
youth authority). Some are operated by county and city governments.
These public training schools are specialized institutions serving
delinquent children, generally between the ages of 10 and 17 years
old, all of whom are committed by the courts.
Private Training Schools--Operated under private auspices. Some of the
children they serve are committed by the courts as delinquents. Others
are referred by parents or social agencies because of delinquent
behavior. One difference between private and public training schools
is that, by their administrative policy, private schools have control
over their selection and intake.
Detention Centers--Includes institutions providing short-term care (usually
30 days or less) primarily for delinquent children pending disposition of
their cases by a court. This category also covers diagnostic centers. In
practice, such institutions may be caring for both delinquent and neglected
children pending court disposition.
Other Persons in Group Quarters (also referred to as "noninstitutional
group quarters")--Includes all persons who live in group quarters other
than institutions. Persons who live in the following living quarters are
classified as "other persons in group quarters" when there are 10
or more unrelated persons living in the unit; otherwise, these living
quarters are classified as housing units.
Rooming Houses--Includes persons residing in rooming and boarding houses
and living in quarters with 10 or more unrelated persons.
Group Homes--Includes "community-based homes" that provide care and
supportive services. Such places include homes for the mentally ill,
mentally retarded, and physically handicapped; drug/alcohol halfway houses;
communes; and maternity homes for unwed mothers.
Homes for the Mentally Ill--Includes community-based homes that provide
care primarily for the mentally ill. In some data products, this category
is classified by type of ownership as "Federal," "State," "Private," and
"Ownership not known." Homes which combine treatment of the physically
handicapped with treatment of the mentally ill are counted as homes for the
mentally ill.
Homes for the Mentally Retarded--Includes community-based homes that
provide care primarily for the mentally retarded. Homes which combine
treatment of the physically handicapped with treatment of the mentally
retarded are counted as homes for the mentally retarded. This category is
classified by type of ownership in some census products, as "Federal,"
"State," "Private," or "Ownership not known."
Homes for the Physically Handicapped--Includes community-based homes for
the blind, for the deaf, and other community-based homes for the physically
handicapped. Persons with speech problems are classified with homes for the
deaf. In some census products, this category is classified by type of
ownership as "Public," "Private," or "Ownership not known."
Homes or Halfway Houses for Drug/Alcohol Abuse--Includes persons with no
usual home elsewhere in places that provide community-based care and
supportive services to persons suffering from a drug/alcohol addiction and
to recovering alcoholics and drug abusers. Places providing community-based
care for drug and alcohol abusers include group homes, detoxification
centers, quarterway houses (residential treatment facilities that work
closely with accredited hospitals), halfway houses, and recovery homes for
ambulatory, mentally competent recovering alcoholics and drug abusers
who may be re-entering the work force.
Maternity Homes for Unwed Mothers--Includes persons with no usual home
elsewhere in places that provide domestic care for unwed mothers and their
children. These homes may provide social services and post-natal care
within the facility, or may make arrangements for women to receive such
services in the community. Nursing services are usually available in the
facility.
Other Group Homes--Includes persons with no usual home elsewhere in
communes, foster care homes, and job corps centers with 10 or more
unrelated persons. These types of places provide communal living quarters,
generally for persons who have formed their own community in which they
have common interests and often share or own property jointly.
Religious Group Quarters--Includes, primarily, group quarters for nuns
teaching in parochial schools and for priests living in rectories. It also
includes other convents and monasteries, except those associated with a
general hospital or an institution.
College Quarters Off Campus--Includes privately-owned rooming and boarding
houses off campus, if the place is reserved exclusively for occupancy by
college students and if there are 10 or more unrelated persons. In census
products, persons in this category are classified as living in a college
dormitory.
Persons residing in certain other types of living arrangements are
classified as living in "noninstitutional group quarters" regardless of the
number of people sharing the unit. These include persons residing in the
following types of group quarters:
College Dormitories--Includes college students in
dormitories (provided the dormitory is restricted to students who do
not have their families living with them), fraternity and sorority
houses, and on-campus residential quarters used exclusively for those
in religious orders who are attending college. Students in
privately-owned rooming and boarding houses off campus are also
included, if the place is reserved exclusively for occupancy by
college-level students and if there are 10 or more unrelated persons.
Military Quarters--Includes military personnel living
in barracks and dormitories on base, in transient quarters on base for
temporary residents (both civilian and military), and on military
ships. However, patients in military hospitals receiving treatment for
chronic diseases or who had no usual home elsewhere, and persons being
held in military stockades were included as part of the institutional
population.
Agriculture Workers' Dormitories--Includes persons in
migratory farm workers' camps on farms, bunkhouses for ranch hands, and
other dormitories on farms, such as those on "tree farms."
Other Workers' Dormitories--Includes persons in logging
camps, construction workers' camps, firehouse dormitories, job-training
camps, energy enclaves (Alaska only), and nonfarm migratory workers'
camps (for example, workers in mineral and mining camps).
Emergency Shelters for Homeless Persons (with sleeping
facilities) and Visible in Street Locations--Includes persons
enumerated during the "Shelter-and-Street-Night" operation primarily on
March 20-21, 1990. Enumerators were instructed not to ask if a person
was "homeless." If a person was at one of the locations below on March
20-21, the person was counted as described below. (For more information
on the "Shelter-and-Street-Night" operation, see Appendix D, Collection
and Processing Procedures.) This category is divided into four
classifications:
Emergency Shelters for Homeless Persons (with sleeping
facilities)--Includes persons who stayed overnight on March 20,
1990, in permanent and temporary emergency housing, missions,
hotels/motels, and flophouses charging $12 or less (excluding taxes)
per night; Salvation Army shelters, hotels, and motels used
entirely for homeless persons regardless of the nightly rate
charged; rooms in hotels and motels used partially for the
homeless; and similar places known to have persons who have no usual
home elsewhere staying overnight. If not shown separately, shelters
and group homes that provide temporary sleeping facilities for
runaway, neglected, and homeless children are included in this
category in data products.
Shelters for Runaway, Neglected, and Homeless Children--Includes
shelters/group homes which provide temporary sleeping facilities for
juveniles.
Visible in Street Locations--Includes street blocks and open public
locations designated before March 20, 1990, by city and community officials
as places where the homeless congregate at night. All persons found at
predesignated street sites from 2 a.m. to 4 a.m. and leaving abandoned or
boarded-up buildings from 4 a.m. to 8 a.m. on March 21, 1990, were
enumerated during "street" enumeration, except persons in uniform such as
police and persons engaged in obvious money-making activities other than
begging or panhandling. Enumerators were instructed not to ask if a
person was "homeless."
This cannot be considered a complete count of all persons living on the
streets because those who were so well hidden that local people did not
know where to find them were likely to have been missed as were persons
moving about or in places not identified by local officials. It is also
possible that persons with homes could have been included in the count
of "visible in street locations" if they were present when the
enumerator did the enumeration of a particular block.
Predesignated street sites include street corners, parks, bridges,
persons emerging from abandoned and boarded-up buildings, noncommercial
campsites (tent cities), all-night movie theaters, all-night
restaurants, emergency hospital waiting rooms, train stations,
airports, bus depots, and subway stations.
Shelters for Abused Women (Shelters Against Domestic Violence or Family
Crisis Centers)--Includes community-based homes or shelters that provide
domiciliary care for women who have sought shelter from family violence and
who may have been physically abused. Most shelters also provide care for
children of abused women. These shelters may provide social services,
meals, psychiatric treatment, and counseling. In some census products,
"shelters for abused women" are included in the category "other
noninstitutional group quarters."
Dormitories for Nurses and Interns in General and Military
Hospitals--Includes group quarters for nurses and other staff
members. It excludes patients.
Crews of Maritime Vessels--Includes officers, crew members, and passengers
of maritime U.S. flag vessels. All ocean-going and Great Lakes ships are
included.
Staff Residents of Institutions--Includes staff residing in group quarters
on institutional grounds who provide formally-authorized, supervised care
or custody for the institutionalized population.
Other Nonhousehold Living Situations--Includes persons with no usual home
elsewhere enumerated during transient or "T-Night" enumeration at YMCA's,
YWCA's, youth hostels, commercial and government-run campgrounds,
campgrounds at racetracks, fairs, and carnivals, and similar transient
sites.
Living Quarters for Victims of Natural Disasters--Includes living quarters
for persons temporarily displaced by natural disasters.
Limitation of the Data--Two types of errors can occur in the classification
of "types of group quarters":
Misclassification of Group Quarters--During the 1990 Special Place
Prelist operation, the enumerator determined the type of group quarters
associated with each special place in their assignment. The enumerator
used the Alphabetical Group Quarters Code List and Index to the
Alphabetical Group Quarters Code List to assign a two-digit code
number followed by either an "I," for institutional, or an
"N," for noninstitutional to each group quarters. In 1990,
unacceptable group quarter codes were edited. (For more information on
editing of unacceptable data, see Appendix C, Accuracy of the Data.)
No Classification (unknowns)--The imputation rate for type of
institution was higher in 1980 (23.5 percent) than in 1970 (3.3
percent). Improvements were made to the 1990 Alphabetical Group
Quarters Code List; that is, the inclusion of more group quarters
categories and an "Index to the Alphabetical Group Quarters Code
List." (For more information on the allocation rates for Type of
Institution, see the allocation rates in 1990 CP-1, General
Population Characteristics.)
In previous censuses, allocation rates for demographic characteristics
(such as age, sex, race, and marital status) of the institutional
population were similar to those for the total population. The allocation
rates for sample characteristics such as school enrollment, highest grade
completed, income, and veteran status for the institutional and
noninstitutional group quarters population have been substantially higher
than the population in households at least as far back as the 1960 census.
The data, however, have historically presented a reasonable picture of the
institutional and noninstitutional group quarters population.
Shelter and Street Night (S-Night)--For the 1990 census "Shelter-and-
Street-Night" operation, persons well hidden, moving about, or in locations
enumerators did not visit were likely to be missed. The number of people
missed will never be known; thus, the 1990 census cannot be considered to
include a definitive count of America's total homeless population. It does,
however, give an idea of relative differences among areas of the country.
Other components were counted as part of regular census procedures.
The count of persons in shelters and visible on the street could have
been affected by many factors. How much the factors affected the count
can never be answered definitively, but some elements include:
How well enumerators were trained and how well they followed
procedures.
How well the list of shelter and street locations given to the
Census Bureau by the local government reflected the actual places that
homeless persons stay at night.
Cities were encouraged to open temporary shelters for census night,
and many did that and actively encouraged people to enter the shelters.
Thus, people who may have been on the street otherwise were in shelters
the night of March 20, so that the ratio of shelter-to-street
population could be different than usual.
The weather, which was unusually cold in some parts of the country,
could affect how likely people were to seek emergency shelter or to be
more hidden than usual if they stayed outdoors.
The media occasionally interfered with the ability to do the count.
How homeless people perceived the census and whether they wanted to
be counted or feared the census and hid from it.
The Census Bureau conducted two assessments of Shelter and Street
Night: (1) the quality of the lists of shelters used for the
Shelter-and-Street-Night operation, and (2) how well procedures were
followed by census- takers for the street count in parts of five cities
(Chicago, Los Angeles, New Orleans, New York, and Phoenix). Information
about these two assessments is available from the Chief, Center for
Survey Methods Research, Bureau of the Census, Washington, DC 20233.
Comparability--For the 1990 census, the definition of institutionalized
persons was revised so that the definition of "care" only includes persons
under organized medical or formally-authorized, supervised care or
custody. As a result of this change to the institutional definition,
maternity homes are classified as noninstitutional rather than
institutional group quarters as in previous censuses. The following
types of other group quarters are classified as institutional rather
than noninstitutional group quarters: "halfway houses (operated for
correctional purposes)" and "wards in general and military
hospitals for patients who have no usual home elsewhere," which
includes maternity, neonatal, pediatric, military, and surgical wards
of hospitals, other-purpose wards of hospitals, and wards for
infectious diseases. These changes should not significantly affect the
comparability of data with earlier censuses because of the relatively
small number of persons involved.
As in 1980, 10 or more unrelated persons living together were
classified as living in noninstitutional group quarters. In 1970, the
criteria was six or more unrelated persons.
Several changes also have occurred in the identification of specific
types of group quarters. For the first time, the 1990 census identifies
separately the following types of correctional institutions: persons in
halfway houses (operated for correctional purposes), military stockades
and jails, and police lockups. In 1990, tuberculosis hospitals or wards
are included with hospitals for the chronically ill; in 1980, they were
shown separately. For 1990, the noninstitutional group quarters
category, "Group homes" is further classified as: group homes for
drug/alcohol abuse; maternity homes (for unwed mothers), group homes
for the mentally ill, group homes for the mentally retarded, and group
homes for the physically handicapped. Persons living in communes,
foster-care homes, and job corps centers are classified with "Other
group homes" only if 10 or more unrelated persons share the unit;
otherwise, they are classified as housing units.
In 1990, workers' dormitories were classified as group quarters
regardless of the number of persons sharing the dorm. In 1980, 10 or
more unrelated persons had to share the dorm for it to be classified as
a group quarters. In 1960, data on persons in military barracks were
shown only for men. In subsequent censuses, they include both men and
women.
In 1990 census data products, the phrase "inmates of institutions" was
changed to "institutionalized persons." Also, persons living in
noninstitutional group quarters were referred to as "other persons in group
quarters," and the phrase "staff residents" was used for staff living in
institutions.
In 1990, there are additional institutional categories and noninstitutional
group quarters categories compared with the 1980 census. The institutional
categories added include "hospitals and wards for drug/alcohol abuse" and
"military hospitals for the chronically ill." The noninstitutional group
quarters categories added include emergency shelters for homeless persons;
shelters for runaway, neglected, and homeless children; shelters for abused
women; and visible-in-street locations. Each of these noninstitutional
group quarters categories was enumerated on March 20-21, 1990, during the
"Shelter-and-Street-Night" operation. (For more information on
the "Shelter-and-Street-Night" operation, see Appendix D, Collection and
Processing Procedures.)
HISPANIC ORIGIN--The data on Spanish/Hispanic origin were derived from
answers to questionnaire item 7, which was asked of all persons. Persons of
Hispanic origin are those who classified themselves in one of the
specific Hispanic origin categories listed on the questionnaire--"Mexican,"
"Puerto Rican," or "Cuban"--as well as those who indicated that they were
of "other Spanish/Hispanic" origin. Persons of "Other Spanish/Hispanic"
origin are those whose origins are from Spain, the Spanish-speaking
countries of Central or South America, or the Dominican Republic, or they
are persons of Hispanic origin identifying themselves generally as Spanish,
Spanish-American, Hispanic, Hispano, Latino, and so on. Write-in responses
to the "other Spanish/Hispanic" category were coded only for sample data.
Origin can be viewed as the ancestry, nationality group, lineage, or
country of birth of the person or the person's parents or ancestors
before their arrival in the United States. Persons of Hispanic origin
may be of any race.
Some tabulations are shown by the Hispanic origin of the householder.
In all cases where households, families, or occupied housing units are
classified by Hispanic origin, the Hispanic origin of the householder
is used. (See the discussion of householder under "Household Type
and Relationship.")
During direct interviews conducted by enumerators, if a person could
not provide a single origin response, he or she was asked to select,
based on self-identification, the group which best described his or her
origin or descent. If a person could not provide a single group, the
origin of the person's mother was used. If a single group could not be
provided for the person's mother, the first origin reported by the
person was used.
If any household member failed to respond to the Spanish/Hispanic
origin question, a response was assigned by the computer according to
the reported entries of other household members by using specific rules
of precedence of household relationship. In the processing of sample
questionnaires, responses to other questions on the questionnaire, such
as ancestry and place of birth, were used to assign an origin before
any reference was made to the origin reported by other household
members. If an origin was not entered for any household member, an
origin was assigned from another household according to the race of the
householder. This procedure is a variation of the general imputation
process described in Appendix C, Accuracy of the Data.
Comparability--There may be differences between the total Hispanic origin
population based on 100-percent tabulations and sample tabulations. Such
differences are the result of sampling variability, nonsampling error,
and more extensive edit procedures for the Spanish/Hispanic origin item
on the sample questionnaires. (For more information on sampling
variability and nonsampling error, see Appendix C, Accuracy of the
Data.)
The 1990 data on Hispanic origin are generally comparable with those
for the 1980 census. However, there are some differences in the format
of the Hispanic origin question between the two censuses. For 1990, the
word "descent" was deleted from the 1980 wording. In addition,
the term "Mexican-Amer." used in 1980 was shortened further to
"Mexican-Am." to reduce misreporting (of "American") in
this category detected in the 1980 census. Finally, the 1990 question
allowed those who reported as "other Spanish/Hispanic" to write
in their specific Hispanic origin group.
Misreporting in the "Mexican-Amer." category of the 1980 census
item on Spanish/Hispanic origin may affect the comparability of 1980
and 1990 census data for persons of Hispanic origin for certain areas
of the country. An evaluation of the 1980 census item on
Spanish/Hispanic origin indicated that there was misreporting in the
Mexican origin category by White and Black persons in certain areas.
The study results showed evidence that the misreporting occurred in the
South (excluding Texas), the Northeast (excluding the New York City
area), and a few States in the Midwest Region. Also, results based on
available data suggest that the impact of possible misreporting of
Mexican origin in the 1980 census was severe in those portions of the
above-mentioned regions where the Hispanic origin population was
generally sparse. However, national 1980 census data on the Mexican
origin population or total Hispanic origin population at the national
level was not seriously affected by the reporting problem. (For a more
detailed discussion of the evaluation of the 1980 census
Spanish/Hispanic origin item, see the 1980 census Supplementary
Reports.)
The 1990 and 1980 census data on the Hispanic population are not
directly comparable with 1970 Spanish origin data because of a number
of factors: (1) overall improvements in the 1980 and 1990 censuses, (2)
better coverage of the population, (3) improved question designs, and
(4) an effective public relations campaign by the Census Bureau with
the assistance of national and community ethnic groups.
Specific changes in question design between the 1980 and 1970 censuses
included the placement of the category "No, not Spanish/Hispanic"
as the first category in that question. (The corresponding category
appeared last in the 1970 question.) Also, the 1970 category
"Central or South American" was deleted because in 1970 some
respondents misinterpreted the category; furthermore, the designations
"Mexican-American" and "Chicano" were added to the Spanish/Hispanic origin
question in 1980. In the 1970 census, the question on Spanish origin was
asked of only a 5-percent sample of the population.
HOUSEHOLD TYPE AND RELATIONSHIP
Household--A household includes all the persons who occupy a housing unit.
A housing unit is a house, an apartment, a mobile home, a group of rooms,
or a single room that is occupied (or if vacant, is intended for occupancy)
as separate living quarters. Separate living quarters are those in which
the occupants live and eat separately from any other persons in the
building and which have direct access from the outside of the building or
through a common hall. The occupants may be a single family, one person
living alone, two or more families living together, or any other group of
related or unrelated persons who share living arrangements.
In 100-percent tabulations, the count of households or householders
always equals the count of occupied housing units. In sample tabulations,
the numbers may differ as a result of the weighting process.
Persons Per Household--A measure obtained by dividing the number of persons
in households by the number of households (or householders). In cases where
persons in households are cross-classified by race or Hispanic origin,
persons in the household are classified by the race or Hispanic origin of
the householder rather than the race or Hispanic origin of each individual.
Relationship to Householder
Householder--The data on relationship to householder were derived from
answers to questionnaire item 2, which was asked of all persons in housing
units. One person in each household is designated as the householder. In
most cases, this is the person, or one of the persons, in whose name the
home is owned, being bought, or rented and who is listed in column 1 of
the census questionnaire. If there is no such person in the household,
any adult household member 15 years old and over could be designated as
the householder.
Households are classified by type according to the sex of the
householder and the presence of relatives. Two types of householders
are distinguished: a family householder and a nonfamily householder. A
family householder is a householder living with one or more persons
related to him or her by birth, marriage, or adoption. The householder
and all persons in the household related to him or her are family
members. A nonfamily householder is a householder living alone or with
nonrelatives only.
Spouse--Includes a person married to and living with a householder. This
category includes persons in formal marriages, as well as persons in
common-law marriages.
The number of spouses is equal to the number of "married-couple families"
or "married-couple households" in 100-percent tabulations. The number of
spouses, however, is generally less than half of the number of "married
persons with spouse present" in sample tabulations, since more than one
married couple can live in a household, but only spouses of householders
are specifically identified as "spouse." For sample tabulations, the number
of "married persons with spouse present" includes married-couple
subfamilies and married-couple families.
Child--Includes a son or daughter by birth, a stepchild, or adopted child
of the householder, regardless of the child's age or marital status. The
category excludes sons-in-law, daughters-in-law, and foster children.
Natural-Born or Adopted Son/Daughter--A son or daughter of the householder
by birth, regardless of the age of the child. Also, this category includes
sons or daughters of the householder by legal adoption, regardless of the
age of the child. If the stepson/stepdaughter of the householder has been
legally adopted by the householder, the child is still classified as a
stepchild.
Stepson/Stepdaughter--A son or daughter of the householder through marriage
but not by birth, regardless of the age of the child. If the
stepson/stepdaughter of the householder has been legally adopted by the
householder, the child is still classified as a stepchild.
Own Child--A never-married child under 18 years who is a son or daughter by
birth, a stepchild, or an adopted child of the householder. In certain
tabulations, own children are further classified as living with two parents
or with one parent only. Own children of the householder living with two
parents are by definition found only in married-couple families.
In a subfamily, an "own child" is a never-married child under 18
years of age who is a son, daughter, stepchild, or an adopted child of
a mother in a mother-child subfamily, a father in a father-child subfamily,
or either spouse in a married-couple subfamily.
"Related children" in a family include own children and all other persons
under 18 years of age in the household, regardless of marital status, who
are related to the householder, except the spouse of the householder.
Foster children are not included since they are not related to the
householder.
Other Relatives--In tabulations, includes any household member related to
the householder by birth, marriage, or adoption, but not included
specifically in another relationship category. In certain detailed
tabulations, the following categories may be shown:
Grandchild--The grandson or granddaughter of the householder.
Brother/Sister--The brother or sister of the householder, including
stepbrothers, stepsisters, and brothers and sisters by adoption. Brothers-
in-law and sisters-in-law are included in the "Other relative" category on
the questionnaire.
Parent--The father or mother of the householder, including a stepparent or
adoptive parent. Fathers-in-law and mothers-in-law are included in the
"Other relative" category on the questionnaire.
Other Relatives--Anyone not listed in a reported category above who is
related to the householder by birth, marriage, or adoption (brother-in-law,
grandparent, nephew, aunt, mother-in-law, daughter-in-law, cousin, and so
forth).
Nonrelatives--Includes any household member, including foster children not
related to the householder by birth, marriage, or adoption. The following
categories may be presented in more detailed tabulations:
Roomer, Boarder, or Foster Child--Roomer, boarder, lodger, and foster
children or foster adults of the householder.
Housemate or Roommate--A person who is not related to the householder
and who shares living quarters primarily in order to share expenses.
Unmarried Partner--A person who is not related to the householder, who
shares living quarters, and who has a close personal relationship with
the householder.
Other Nonrelatives--A person who is not related by birth, marriage, or
adoption to the householder and who is not described by the categories
given above.
When relationship is not reported for an individual, it is imputed
according to the responses for age, sex, and marital status for that
person while maintaining consistency with responses for other
individuals in the household. (For more information on imputation, see
Appendix C, Accuracy of the Data.)
Unrelated Individual--An unrelated individual is: (1) a householder living
alone or with nonrelatives only, (2) a household member who is not related
to the householder, or (3) a person living in group quarters who is not an
inmate of an institution.
Family Type--A family consists of a householder and one or more other
persons living in the same household who are related to the householder by
birth, marriage, or adoption. All persons in a household who are
related to the householder are regarded as members of his or her
family. A household can contain only one family for purposes of census
tabulations. Not all households contain families since a household may
comprise a group of unrelated persons or one person living alone.
Families are classified by type as either a "married-couple family" or
"other family" according to the sex of the householder and the presence of
relatives. The data on family type are based on answers to questions on sex
and relationship which were asked on a 100-percent basis.
Married-Couple Family--A family in which the householder and his or her
spouse are enumerated as members of the same household.
Other Family:
Male Householder, No Wife Present--A family with a male
householder and no spouse of householder present.
Female Householder, No Husband Present--A family with a
female householder and no spouse of householder present.
Persons Per Family--A measure obtained by dividing the number of persons in
families by the total number of families (or family householders). In cases
where the measure, "persons in family" or "persons per family" are
cross-tabulated by race or Hispanic origin, the race or Hispanic origin
refers to the householder rather than the race or Hispanic origin of
each individual.
Subfamily--A subfamily is a married couple (husband and wife enumerated as
members of the same household) with or without never-married children
under 18 years old, or one parent with one or more never-married
children under 18 years old, living in a household and related to, but
not including, either the householder or the householder's spouse. The
number of subfamilies is not included in the count of families, since
subfamily members are counted as part of the householder's family.
Subfamilies are defined during processing of sample data. In selected
tabulations, subfamilies are further classified by type: married-couple
subfamilies, with or without own children; mother-child subfamilies;
and father-child subfamilies.
Lone parents include people maintaining either one-parent families or one-
parent subfamilies. Married couples include husbands and wives in both
married-couple families and married-couple subfamilies.
Unmarried-Partner Household--An unmarried-partner household is a household
other than a "married-couple household" that includes a householder and an
"unmarried partner." An "unmarried partner" can be of the same sex or of
the opposite sex of the householder. An "unmarried partner" in an
"unmarried- partner household" is an adult who is unrelated to the
householder, but shares living quarters and has a close personal
relationship with the householder.
Unmarried-Couple Household--An unmarried-couple household is composed of
two unrelated adults of the opposite sex (one of whom is the householder)
who share a housing unit with or without the presence of children under 15
years old.
Foster Children--Foster children are nonrelatives of the householder and
are included in the category, "Roomer, boarder, or foster child" on the
questionnaire. Foster children are identified as persons under 18 years
old and living in households that have no nonrelatives 18 years old and
over (who might be parents of the nonrelatives under 18 years old).
Stepfamily--A stepfamily is a "married-couple family" with at least one
stepchild of the householder present, where the householder is the
husband.
Comparability--The 1990 definition of a household is the same as that used
in 1980. The 1980 relationship category "Son/daughter" has been replaced
by two categories, "Natural-born or adopted son/daughter" and "Stepson/
stepdaughter." "Grandchild" has been added as a separate category. The 1980
nonrelative categories: "Roomer, boarder" and "Partner, roommate" have been
replaced by the categories "Roomer, boarder, or foster child," "Housemate,
roommate," and "Unmarried partner." The 1980 nonrelative category "Paid
employee" has been dropped.
INCOME IN 1989--The data on income in 1989 were derived from answers to
questionnaire items 32 and 33. Information on money income received in
the calendar year 1989 was requested from persons 15 years old and
over. "Total income" is the algebraic sum of the amounts reported
separately for wage or salary income; net nonfarm self-employment
income; net farm self-employment income; interest, dividend, or net
rental or royalty income; Social Security or railroad retirement
income; public assistance or welfare income; retirement or disability
income; and all other income. "Earnings" is defined as the
algebraic sum of wage or salary income and net income from farm and
nonfarm self-employment. "Earnings" represent the amount of
income received regularly before deductions for personal income taxes,
Social Security, bond purchases, union dues, medicare deductions, etc.
Receipts from the following sources are not included as income: money
received from the sale of property (unless the recipient was engaged in
the business of selling such property); the value of income "in
kind" from food stamps, public housing subsidies, medical care,
employer contributions for persons, etc.; withdrawal of bank deposits;
money borrowed; tax refunds; exchange of money between relatives living
in the same household; gifts and lump-sum inheritances, insurance
payments, and other types of lump-sum receipts.
Income Type in 1989--The eight types of income reported in the census are
defined as follows:
Wage or Salary Income--Includes total money earnings
received for work performed as an employee during the calendar year
1989. It includes wages, salary, Armed Forces pay, commissions, tips,
piece-rate payments, and cash bonuses earned before deductions were made
for taxes, bonds, pensions, union dues, etc.
Nonfarm Self-Employment Income--Includes net money income (gross
receipts minus expenses) from one's own business, professional
enterprise, or partnership. Gross receipts include the value of all
goods sold and services rendered. Expenses includes costs of goods
purchased, rent, heat, light, power, depreciation charges, wages and
salaries paid, business taxes (not personal income taxes), etc.
Farm Self-Employment Income--Includes net money income (gross receipts
minus operating expenses) from the operation of a farm by a person on
his or her own account, as an owner, renter, or sharecropper. Gross
receipts include the value of all products sold, government farm
programs, money received from the rental of farm equipment to others,
and incidental receipts from the sale of wood, sand, gravel, etc.
Operating expenses include cost of feed, fertilizer, seed, and other
farming supplies, cash wages paid to farmhands, depreciation charges,
cash rent, interest on farm mortgages, farm building repairs, farm taxes
(not State and Federal personal income taxes), etc. The value of fuel,
food, or other farm products used for family living is not included as
part of net income.
Interest, Dividend, or Net Rental Income--Includes interest on savings
or bonds, dividends from stockholdings or membership in associations,
net income from rental of property to others and receipts from boarders
or lodgers, net royalties, and periodic payments from an estate or trust
fund.
Social Security Income--Includes Social Security pensions and survivors
benefits and permanent disability insurance payments made by the Social
Security Administration prior to deductions for medical insurance, and
railroad retirement insurance checks from the U.S. Government. Medicare
reimbursements are not included.
Public Assistance Income--Includes: (1) supplementary security income
payments made by Federal or State welfare agencies to low income persons
who are aged (65 years old or over), blind, or disabled; (2) aid to
families with dependent children, and (3) general assistance. Separate
payments received for hospital or other medical care (vendor payments)
are excluded from this item.
Retirement or Disability Income--Includes: (1) retirement pensions and
survivor benefits from a former employer, labor union, or Federal,
State, county, or other governmental agency; (2) disability income from
sources such as worker's compensation; companies or unions; Federal,
State, or local government; and the U.S. military; (3) periodic receipts
from annuities and insurance; and (4) regular income from IRA and KEOGH
plans.
All Other Income--Includes unemployment compensation, Veterans
Administration (VA) payments, alimony and child support,
contributions received periodically from persons not living in the
household, military family allotments, net gambling winnings, and other
kinds of periodic income other than earnings.
Income of Households--Includes the income of the householder and all other
persons 15 years old and over in the household, whether related to the
householder or not. Because many households consist of only one person,
average household income is usually less than average family income.
Income of Families and Persons--In compiling statistics on family income,
the incomes of all members 15 years old and over in each family are summed
and treated as a single amount. However, for persons 15 years old and over,
the total amounts of their own incomes are used. Although the income
statistics covered the calendar year 1989, the characteristics of persons
and the composition of families refer to the time of enumeration (April
1990). Thus, the income of the family does not include amounts received by
persons who were members of the family during all or part of the
calendar year 1989 if these persons no longer resided with the family
at the time of enumeration. Yet, family income amounts reported by
related persons who did not reside with the family during 1989 but who
were members of the family at the time of enumeration are included.
However, the composition of most families was the same during 1989 as
in April 1990.
Median Income--The median divides the income distribution into two equal
parts, one having incomes above the median and the other having incomes
below the median. For households and families, the median income is based
on the distribution of the total number of units including those with no
income. The median for persons is based on persons with income. The
median income values for all households, families, and persons are
computed on the basis of more detailed income intervals than shown in
most tabulations. Median household or family income figures of $50,000
or less are calculated using linear interpolation. For persons,
corresponding median values of $40,000 or less are also computed using
linear interpolation. All other median income amounts are derived
through Pareto interpolation. (For more information on medians and
interpolation, see the discussion under "Derived Measures.")
Mean Income--This is the amount obtained by dividing the total income of a
particular statistical universe by the number of units in that universe.
Thus, mean household income is obtained by dividing total household income
by the total number of households. For the various types of income the
means are based on households having those types of income. "Per capita
income" is the mean income computed for every man, woman, and child in a
particular group. It is derived by dividing the total income of a
particular group by the total population in that group.
Care should be exercised in using and interpreting mean income values
for small subgroups of the population. Because the mean is influenced
strongly by extreme values in the distribution, it is especially
susceptible to the effects of sampling variability, misreporting, and
processing errors. The median, which is not affected by extreme values,
is, therefore, a better measure than the mean when the population base
is small. The mean, nevertheless, is shown in some data products for
most small subgroups because, when weighted according to the number of
cases, the means can be added to obtained summary measures for areas
and groups other than those shown in census tabulations.
Limitation of the Data--Since questionnaire entries for income frequently
are based on memory and not on records, many persons tended to forget minor
or irregular sources of income and, therefore, underreport their income.
Underreporting tends to be more pronounced for income sources that are
not derived from earnings, such as Social Security, public assistance,
or from interest, dividends, and net rental income.
There are errors of reporting due to the misunderstanding of the income
questions such as reporting gross rather than net dollar amounts for
the two questions on net self-employment income, which resulted in an
overstatement of these items. Another common error is the reporting of
identical dollar amounts in two of the eight type of income items where
a respondent with only one source of income assumed that the second
amount should be entered to represent total income. Such instances of
overreporting had an impact on the level of mean nonfarm or farm
self-employment income and mean total income published for the various
geographical subdivisions of the State.
Extensive computer editing procedures were instituted in the data
processing operation to reduce some of these reporting errors and to
improve the accuracy of the income data. These procedures corrected
various reporting deficiencies and improved the consistency of reported
income items associated with work experience and information on
occupation and class of worker. For example, if persons reported they
were self-employed on their own farm, not incorporated, but had
reported wage and salary earnings only, the latter amount was shifted
to net farm self-employment income. Also, if any respondent reported total
income only, the amount was generally assigned to one of the type of income
items according to responses to the work experience and class-of-worker
questions. Another type of problem involved nonreporting of income
data. Where income information was not reported, procedures were
devised to impute appropriate values with either no income or positive
or negative dollar amounts for the missing entries. (For more
information on imputation, see Appendix C, Accuracy of the Data.)
In income tabulations for households and families, the lowest income
group (e.g., less than $5,000) includes units that were classified as
having no 1989 income. Many of these were living on income "in
kind," savings, or gifts, were newly created families, or families
in which the sole breadwinner had recently died or left the household.
However, many of the households and families who reported no income
probably had some money income which was not recorded in the census.
The income data presented in the tabulations covers money income only.
The fact that many farm families receive an important part of their
income in the form of "free" housing and goods produced and
consumed on the farm rather than in money should be taken into
consideration in comparing the income of farm and nonfarm residents.
Nonmoney income such as business expense accounts, use of business
transportation and facilities, or partial compensation by business for
medical and educational expenses was also received by some nonfarm
residents. Many low income families also receive income "in kind"
from public welfare programs. In comparing income data for 1989 with
earlier years, it should be noted that an increase or decrease in money
income does not necessarily represent a comparable change in real
income, unless adjustments for changes in prices are made.
Comparability--The income data collected in the 1980 and 1970 censuses are
similar to the 1990 census data, but there are variations in the detail of
the questions. In 1980, income information for 1979 was collected from
persons in approximately 19 percent of all housing units and group
quarters. Each person was required to report:
Wage or salary income
Net nonfarm self-employment income
Net farm self-employment income
Interest, dividend, or net rental or royalty income Social Security
income
Public assistance income
Income from all other sources
Between the 1980 and 1990 censuses, there were minor differences in
the processing of the data. In both censuses, all persons with missing
values in one or more of the detailed type of income items
and total income were designated as allocated. Each
missing entry was imputed either as a "no" or as a dollar amount.
If total income was reported and one or more of the type of
income fields was not answered, then the entry in total income
generally was assigned to one of the income types according to the
socioeconomic characteristics of the income recipient. This person was
designated as unallocated.
In 1980 and 1990, all nonrespondents with income not reported (whether
heads of households or other persons) were assigned the reported income
of persons with similar characteristics. (For more information on
imputation, see Appendix C, "Accuracy of the Data.")
There was a difference in the method of computer derivation of
aggregate income from individual amounts between the two census
processing operations. In the 1980 census, income amounts less than
$100,000 were coded in tens of dollars, and amounts of $100,000 or more
were coded in thousands of dollars; $5 was added to each amount coded
in tens of dollars and $500 to each amount coded in thousands of
dollars. Entries of $999,000 or more were treated as $999,500 and
losses of $9,999 or more were treated as minus $9,999. In the 1990
census, income amounts less than $999,999 were keyed in dollars.
Amounts of $999,999 or more were treated as $999,999 and losses of
$9,999 or more were treated as minus $9,999 in all of the computer
derivations of aggregate income.
In 1970, information on income in 1969 was obtained from all members in
every fifth housing unit and small group quarters (less than 15
persons) and every fifth person in all other group quarters. Each
person was required to report:
Wage or salary income
Net nonfarm self-employment income
Net farm self-employment income
Social Security or Railroad Retirement
Public assistance or welfare payments
Income from all other sources
If a person reported a dollar amount in wage or salary, net nonfarm
self-employment income, or net farm self-employment income, the person was
considered as unallocated only if no further dollar amounts were imputed
for any additional missing entries.
In 1960, data on income were obtained from all members in every fourth
housing unit and from every fourth person 14 years old and over living
in group quarters. Each person was required to report wage or salary
income, net self-employment income, and income other than earnings
received in 1959. An assumption was made in the editing process that no
other type of income was received by a person who reported the receipt
of either wage and salary income or self-employment but who had failed
to report the receipt of other money income.
For several reasons, the income data shown in census tabulations are
not directly comparable with those that may be obtained from
statistical summaries of income tax returns. Income, as defined for
Federal tax purposes, differs somewhat from the Census Bureau concept.
Moreover, the coverage of income tax statistics is different because of
the exemptions of persons having small amounts of income and the
inclusion of net capital gains in tax returns. Furthermore, members of
some families file separate returns and others file joint returns;
consequently, the income reporting unit is not consistently either a
family or a person.
The earnings data shown in census tabulations are not directly
comparable with earnings records of the Social Security Administration.
The earnings record data for 1989 excluded the earnings of most
civilian government employees, some employees of nonprofit
organizations, workers covered by the Railroad Retirement Act, and
persons not covered by the program because of insufficient earnings.
Furthermore, earnings received from any one employer in excess of
$48,000 in 1989 are not covered by earnings records. Finally, because
census data are obtained from household questionnaires, they may differ
from Social Security Administration earnings record data, which are
based upon employers' reports and the Federal income tax returns of
self-employed persons.
The Bureau of Economic Analysis (BEA) of the Department of Commerce
publishes annual data on aggregate and per-capita personal income
received by the population for States, metropolitan areas, and selected
counties. Aggregate income estimates based on the income statistics
shown in census products usually would be less than those shown in the
BEA income series for several reasons. The Census Bureau data are
obtained directly from households, whereas the BEA income series is
estimated largely on the basis of data from administrative records of
business and governmental sources. Moreover, the definitions of income
are different. The BEA income series includes some items not included
in the income data shown in census publications, such as income "in
kind," income received by nonprofit institutions, the value of
services of banks and other financial intermediaries rendered to
persons without the assessment of specific charges, Medicare payments,
and the income of persons who died or emigrated prior to April 1, 1990.
On the other hand, the census income data include contributions for
support received from persons not residing in the same household and
employer contributions for social insurance.
INDUSTRY, OCCUPATION, AND CLASS OF WORKER--The data on industry,
occupation, and class of worker were derived from answers to questionnaire
items 28, 29, and 30 respectively. These questions were asked of a sample
of persons. Information on industry relates to the kind of business
conducted by a person's employing organization; occupation describes the
kind of work the person does on the job.
For employed persons, the data refer to the person's job during the
reference week. For those who worked at two or more jobs, the data
refer to the job at which the person worked the greatest number of
hours. For unemployed persons, the data refer to their last job. The
industry and occupation statistics are derived from the detailed
classification systems developed for the 1990 census as described
below. The Classified Index of Industries and Occupations
provided additional information on the industry and occupation
classification systems.
Respondents provided the data for the tabulations by writing on the
questionnaires descriptions of their industry and occupation. These
descriptions were keyed and passed through automated coding software
which assigned a portion of the written entries to categories in the
classification system. The automated system assigned codes to 59
percent of the industry entries and 38 percent of the occupation
entries.
Those cases not coded by the computer were referred to clerical staff
in the Census Bureau's Kansas City processing office for coding. The
clerical staff converted the written questionnaire descriptions to
codes by comparing these descriptions to entries in the
Alphabetical Index of Industries and Occupations. For the
industry code, these coders also referred to an Employer Name List
(formerly called Company Name List). This list, prepared from the
Standard Statistical Establishment List developed by the Census Bureau
for the economic censuses and surveys, contained the names of business
establishments and their Standard Industrial Classification (SIC) codes
converted to population census equivalents. This list facilitated
coding and maintained industrial classification comparability.
Industry--The industry classification system developed for the 1990 census
consists of 235 categories for employed persons, classified into 13
major industry groups. Since 1940, the industrial classification has
been based on the Standard Industrial Classification Manual (SIC). The
1990 census classification was developed from the 1987 SIC published by
the Office of Management and Budget Executive Office of the President.
The SIC was designed primarily to classify establishments by the type
of industrial activity in which they were engaged. However, census
data, which were collected from households, differ in detail and nature
from those obtained from establishment surveys. Therefore, the census
classification systems, while defined in SIC terms, cannot reflect the
full detail in all categories. There are several levels of industrial
classification found in census products. For example, the 1990 CP-2,
Social and Economic Characteristics report includes 41
unique industrial categories, while the 1990 Summary Tape File 4 (STF
4) presents 72 categories.
Occupation--The occupational classification system developed for the 1990
census consists of 500 specific occupational categories for employed
persons arranged into 6 summary and 13 major occupational groups. This
classification was developed to be consistent with the Standard
Occupational Classification (SOC) Manual: 1980, published by the Office
of Federal Statistical Policy and Standards, U.S. Department of
Commerce. Tabulations with occupation as the primary characteristic
present several levels of occupational detail. The most detailed
tabulations are shown in a special 1990 subject report and tape files
on occupation. These products contain all 500 occupational categories
plus industry or class of worker subgroupings of occupational
categories.
Some occupation groups are related closely to certain industries.
Operators of transportation equipment, farm operators and workers, and
private household workers account for major portions of their
respective industries of transportation, agriculture, and private
households. However, the industry categories include persons in other
occupations. For example, persons employed in agriculture include truck
drivers and bookkeepers; persons employed in the transportation
industry include mechanics, freight handlers, and payroll clerks; and
persons employed in the private household industry include occupations
such as chauffeur, gardener, and secretary.
Class of Worker--The data on class of worker were derived from answers to
questionnaire item 30. The information on class of worker refers to the
same job as a respondent's industry and occupation and categorizes
persons according to the type of ownership of the employing
organization. The class of worker categories are defined as follows:
Private Wage and Salary Workers--Includes persons who worked for wages,
salary, commission, tips, pay-in-kind, or piece rates for a private for
profit employer or a private not-for-profit, tax-exempt or charitable
organization. Self-employed persons whose business was incorporated are
included with private wage and salary workers because they are paid
employees of their own companies. Some tabulations present data
separately for these subcategories: "For profit," "Not for profit," and
"Own business incorporated."
Employees of foreign governments, the United Nations, or other formal
international organizations were classified as "Private-not-for-profit."
Government Workers--Includes persons who were employees of any local,
State, or Federal governmental unit, regardless of the activity of the
particular agency. For some tabulations, the data were presented
separately for the three levels of government.
Self-Employed Workers--Includes persons who worked for profit or fees in
their own unincorporated business, profession, or trade, or who operated
a farm.
Unpaid Family Workers--Includes persons who worked 15 hours or more
without pay in a business or on a farm operated by a relative.
Salaried/Self-Employed--In tabulations that categorize persons as either
salaried or self-employed, the salaried category includes private and
government wage and salary workers; self-employed includes self-employed
persons and unpaid family workers.
The industry category, "Public administration," is limited to regular
government functions such as legislative, judicial, administrative, and
regulatory activities of governments. Other government organizations
such as schools, hospitals, liquor stores, and bus lines are classified
by industry according to the activity in which they are engaged. On the
other hand, the class of worker government categories include all
government workers.
Occasionally respondents supplied industry, occupation, or class of
worker descriptions which were not sufficiently specific for precise
classification or did not report on these items at all. Some of these
cases were corrected through the field editing process and during the
coding and tabulation operations. In the coding operation, certain
types of incomplete entries were corrected using the Alphabetical
Index of Industries and Occupations. For example, it was possible
in certain situations to assign an industry code based on the
occupation reported.
Following the coding operations, there was a computer edit and an
allocation process. The edit first determined whether a respondent was
in the universe which required an industry and occupation code. The
codes for the three items (industry, occupation, and class of worker)
were checked to ensure they were valid and were edited for their
relation to each other. Invalid and inconsistent codes were either
blanked or changed to a consistent code.
If one or more of the three codes were blank after the edit, a code was
assigned from a "similar" person based on other items such as
age, sex, education, farm or nonfarm residence, and weeks worked. If
all the labor force and income data also were blank, all these economic
items were assigned from one other person who provided all the
necessary data.
Comparability--Comparability of industry and occupation data was affected
by a number of factors, primarily the systems used to classify the
questionnaire responses. For both the industry and occupation
classification systems, the basic structures were generally the same from
1940 to 1970, but changes in the individual categories limited
comparability of the data from one census to another. These changes were
needed to recognize the "birth" of new industries and occupations, the
"death" of others, and the growth and decline in existing industries and
occupations, as well as, the desire of analysts and other users for
more detail in the presentation of the data. Probably the greatest
cause of incomparability is the movement of a segment of a category to
a different category in the next census. Changes in the nature of jobs
and respondent terminology, and refinement of category composition made
these movements necessary.
In the 1990 census, the industry classification had minor revisions to
reflect recent changes to the SIC. The 1990 occupational classification
system is essentially the same as that for the 1980 census. However,
the conversion of the census classification to the SOC in 1980 meant
that the 1990 classification system was less comparable to the
classifications used prior to the 1980 census.
Other factors that affected data comparability included the universe to
which the data referred (in 1970, the age cutoff for labor force was
changed from 14 years to 16 years); how the industry and occupation
questions were worded on the questionnaire (for example, important
changes were made in 1970); improvements in the coding procedures (the
Employer Name List technique was introduced in 1960); and how the
"not reported" cases are handled. Prior to 1970, they were placed
in the residual categories, "Industry not reported" and
"Occupation not reported." In 1970, an allocation process was
introduced that assigned these cases to major groups. In 1990, as in
1980, the "Not reported" cases were assigned to individual
categories. Therefore, the 1980 and 1990 data for individual categories
included some numbers of persons who were tabulated in a "Not
reported" category in previous censuses.
The following publications contain information on the various factors
affecting comparability and are particularly useful for understanding
differences in the occupation and industry information from earlier
censuses: U.S. Bureau of the Census, Changes Between the 1950 and
1960 Occupation and Industry Classifications With Detailed Adjustments
of 1950 Data to the 1960 Classifications, Technical Paper No. 18,
1968; U.S. Bureau of the Census, 1970 Occupation and Industry
Classification Systems in Terms of their 1960 Occupation and Industry
Elements, Technical Paper No. 26, 1972; and U.S. Bureau of the
Census, The Relationship Between the 1970 and 1980 Industry and
Occupation Classification Systems, Technical Paper No. 59, 1988.
For citations for earlier census years, see the 1980 Census of
Population report, PC80-1-D, Detailed Population
Characteristics.
The 1990 census introduced an additional class of worker category for
"private not-for-profit" employers. This category is a subset of
the 1980 category "employee of private employer" so there is no
comparable data before 1990. Also in 1990, employees of foreign
governments, the United Nations, etc., are classified as "private
not-for-profit," rather than Federal Government as in 1970 and 1980. While
in theory, there was a change in comparability, in practice, the small
number of U.S. residents working for foreign governments made this
change negligible.
Comparability between the statistics on industry and occupation from
the 1990 census and statistics from other sources is affected by many
of the factors described in the section on "Employment Status."
These factors are primarily geographic differences between residence
and place of work, different dates of reference, and differences in
counts because of dual job holding. Industry data from population
censuses cover all industries and all kinds of workers, whereas, data
from establishments often excluded private household workers,
government workers, and the self-employed. Also, the replies from
household respondents may have differed in detail and nature from those
obtained from establishments.
Occupation data from the census and data from government licensing
agencies, professional associations, trade unions, etc., may not be as
comparable as expected. Organizational listings often include persons
not in the labor force or persons devoting all or most of their time to
another occupation; or the same person may be included in two or more
different listings. In addition, relatively few organizations, except
for those requiring licensing, attained complete coverage of membership
in a particular occupational field.
JOURNEY TO WORK
Place of Work--The data on place of work were derived from answers to
questionnaire item 22, which was asked of persons who indicated in question
21 that they worked at some time during the reference week. (For more
information, see discussion under "Reference Week.")
Data were tabulated for workers 16 years and over; that is, members of
the Armed Forces and civilians who were at work during the reference
week. Data on place of work refer to the geographic location at which
workers carried out their occupational activities during the reference
week. The exact address (number and street) of the place of work was
asked, as well as the place (city, town, or post office); whether or
not the place of work was inside or outside the limits of that city or
town; and the county, State, and ZIP Code. If the person's employer
operated in more than one location, the exact address of the location
or branch where the respondent worked was requested. When the number
and street name were unknown, a description of the location, such as
the building name or nearest street or intersection, was to be entered.
Persons who worked at more than one location during the reference week
were asked to report the one at which they worked the greatest number
of hours. Persons who regularly worked in several locations each day
during the reference week were requested to give the address at which
they began work each day. For cases in which daily work did not begin
at a central place each day, the person was asked to provide as much
information as possible to describe the area in which he or she worked
most during the reference week.
In some tabulations, place-of-work locations may be defined as "in
area of residence" and "outside area of residence." The area
of residence may vary from table to table or even within a table, and
refers to the particular area or areas shown. For example, in a table
that provides data for counties, "in area of residence" refers to
persons who worked in the same county in which they lived, while
"outside area of residence" refers to persons whose workplace was
located in a county different from the one in which they lived.
Similarly, in a table that provides data for several types of areas,
such as the State and its individual metropolitan areas (MA's),
counties, and places, the place-of-work data will be variable and is
determined by the geographic level (State, MA, county, or place) shown in
each section of the tabulation.
In tabulations that present data for States, workplaces for the
residents of the State may include, in addition to the State itself,
each contiguous State. The category, "in noncontiguous State or
abroad," includes persons who worked in a State that did not border
their State of residence as well as persons who worked outside the
United States.
In tabulations that present data for an MSA/PMSA, place-of-work
locations are specified to show the main destinations of workers living
in the MSA/PMSA. (For more information on metropolitan areas (MA's),
see Appendix A, Area Classifications.) All place-of-work locations are
identified with respect to the boundaries of the MSA/PMSA as "inside
MSA/PMSA" or "outside MSA/PMSA." Locations within the MSA/PMSA
are further divided into each central city, and each county or county
balance. Selected large incorporated places also may be specified as
places of work.
Within New England MSA/PMSA's, the places of work presented generally
are cities and towns. Locations outside the MSA/PMSA are specified if
they are important commuting destinations for residents of the
MSA/PMSA, and may include adjoining MSA/PMSA's and their central
cities, their component counties, large incorporated places, or
counties, cities, or other geographic areas outside any MA. In
tabulations for MSA/PMSA's in New England; Honolulu, Hawaii; and
certain other MA's, some place-of-work locations are identified as "areas"
(e.g., Area 1, Area 5, Area 12, etc.). Such areas consist of groups of
towns, cities, census designated places (Honolulu MSA only), or counties
that have been identified as unique place-of-work destinations. When an
adjoining MSA/PMSA or MSA/PMSA remainder is specified as a place-of-work
location, its components are not defined. However, the components are
presented in the 1990 CP-1, General Population Characteristics
for Metropolitan Areas and the 1990 CH-1, General Housing
Characteristics for Metropolitan Areas reports. In tabulations
that present data for census tracts outside MA's, place-of-work
locations are defined as "in county of residence" and "outside
county of residence."
In areas where the workplace address was coded to the block level,
persons were tabulated as working inside or outside a specific place
based on the location of that address, regardless of the response to
question 22c concerning city/town limits. In areas where it was
impossible to code the workplace address to the block level, persons
were tabulated as working in a place if a place name was reported in
question 22b and the response to question 22c was either "Yes" or
the item was left blank. In selected areas, census designated places
(CDP's) may appear in the tabulations as places of work. The accuracy
of place-of-work data for CDP's may be affected by the extent to which
their census names were familiar to respondents, and by coding problems
caused by similarities between the CDP name and the names of other
geographic jurisdictions in the same vicinity.
Place-of-work data are given for selected minor civil divisions
(generally, cities, towns, and townships) in the nine Northeastern
States, based on the responses to the place-of-work question. Many
towns and townships are regarded locally as equivalent to a place and
therefore, were reported as the place of work. When a respondent
reported a locality or incorporated place that formed a part of a
township or town, the coding and tabulating procedure was designed to
include the response in the total for the township or town. The
accuracy of the place-of-work data for minor civil divisions is
greatest for the New England States. However, the data for some New
England towns, for towns in New York, and for townships in New Jersey
and Pennsylvania may be affected by coding problems that resulted from
the unfamiliarity of the respondent with the minor civil division in
which the workplace was located or when a township and a city or
borough of the same or similar name are located close together.
Place-of-work data may show a few workers who made unlikely daily work
trips (e.g., workers who lived in New York and worked in California).
This result is attributable to persons who worked during the reference
week at a location that was different from their usual place of work,
such as persons away from home on business.
Comparability--The wording of the question on place of work was
substantially the same in the 1990 census as it was in 1980.
However, data on place of work from the 1990 census are based on the
full census sample, while data from the 1980 census were based on only
about one-half of the full sample.
For the 1980 census, nonresponse or incomplete responses to the
place-of-work question were not allocated, resulting in the use of
"not reported" categories in the 1980 publications. However, for
the 1990 census, when place of work was not reported or the response
was incomplete, a work location was allocated to the person based on
their means of transportation to work, travel time to work, industry,
and location of residence and workplace of others. The 1990
publications, therefore, do not contain a "not reported" category
for the place-of-work data.
Comparisons between 1980 and 1990 census data on the gross number of
workers in particular commuting flows, or the total number of persons
working in an area, should be made with extreme caution. Any apparent
increase in the magnitude of the gross numbers may be due solely to the
fact that for 1990 the "not reported" cases have been distributed
among specific place-of-work destinations, instead of tallied in a
separate category as in 1980.
Limitation of the Data--The data on place of work relate to a reference
week; that is, the calendar week preceding the date on which the
respondents completed their questionnaires or were
interviewed by enumerators. This week is not the same for all
respondents because the enumeration was not completed in 1 week.
However, for the majority of persons, the reference week for the 1990
census is the last week in March 1990. The lack of a uniform reference
week means that the place-of-work data reported in the census will not
exactly match the distribution of workplace locations observed or
measured during an actual workweek.
The place-of-work data are estimates of persons 16 years old and over
who were both employed and at work during the reference week (including
persons in the Armed Forces). Persons who did not work during the
reference week but had jobs or businesses from which they were
temporarily absent due to illness, bad weather, industrial dispute,
vacation, or other personal reasons are not included in the
place-of-work data. Therefore, the data on place of work understate the
total number of jobs or total employment in a geographic area during
the reference week. It also should be noted that persons who had
irregular, casual, or unstructured jobs during the reference week may
have erroneously reported themselves as not working.
The address where the individual worked most often during the reference
week was recorded on the census questionnaire. If a worker held two
jobs, only data about the primary job (the one worked the greatest
number of hours during the preceding week) was requested. Persons who
regularly worked in several locations during the reference week were
requested to give the address at which they began work each day. For
cases in which daily work was not begun at a central place each day,
the person was asked to provide as much information as possible to
describe the area in which he or she worked most during the reference
week.
Means of Transportation to Work--The data on means of transportation to
work were derived from answers to questionnaire item 23a, which was asked
of persons who indicated in question 21 that they worked at some time
during the reference week. (For more information, see discussion under
"Reference Week.") Means of transportation to work refers to the
principal mode of travel or type of conveyance that the person usually
used to get from home to work during the reference week.
Persons who used different means of transportation on different days of
the week were asked to specify the one they used most often, that is,
the greatest number of days. Persons who used more than one means of
transportation to get to work each day were asked to report the one
used for the longest distance during the work trip. The category,
"Car, truck, or van," includes workers using a car (including
company cars but excluding taxicabs), a truck of one-ton capacity or
less, or a van. The category, "Public transportation," includes
workers who used a bus or trolley bus, streetcar or trolley car, subway
or elevated, railroad, ferryboat, or taxicab even if each mode is not
shown separately in the tabulation. The category, "Other means,"
includes workers who used a mode of travel which is not identified
separately within the data distribution. The category, "Other
means," may vary from table to table, depending on the amount of
detail shown in a particular distribution.
The means of transportation data for some areas may show workers using
modes of public transportation that are not available in those areas
(e.g., subway or elevated riders in an MA where there actually is no
subway or elevated service). This result is largely due to persons who
worked during the reference week at a location that was different from
their usual place of work (such as persons away from home on business
in an area where subway service was available) and persons who used
more than one means of transportation each day but whose principal
means was unavailable where they lived (for example, residents of
nonmetropolitan areas who drove to the fringe of an MA and took the
commuter railroad most of the distance to work).
Private Vehicle Occupancy--The data on private vehicle occupancy were
derived from answers to questionnaire item 23b. This question was asked of
persons who indicated in question 21 that they worked at some time during
the reference week and who reported in question 23a that their means of
transportation to work was "Car, truck, or van." (For more
information, see discussion under "Reference Week.")
Private vehicle occupancy refers to the number of persons who usually
rode to work in the vehicle during the reference week. The category,
"Drove alone," includes persons who usually drove alone to work
as well as persons who were driven to work by someone who then drove
back home or to a nonwork destination. The category, "Carpooled,"
includes workers who reported that two or more persons usually rode to
work in the vehicle during the reference week.
Persons Per Car, Truck, or Van--This is obtained by dividing the number of
persons who reported using a car, truck, or van to get to work by the
number of such vehicles that they used. The number of vehicles used is
derived by counting each person who drove alone as one vehicle, each person
who reported being in a two-person carpool as one-half vehicle, each person
who reported being in a three-person carpool as one-third vehicle, and so
on, and then summing all the vehicles.
Time Leaving Home to Go to Work--The data on time leaving home to go to
work were derived from answers to questionnaire item 24a. This question was
asked of persons who indicated in question 21 that they worked at some time
during the reference week and who reported in question 23a that they worked
outside their home. The departure time refers to the time of day that
the person usually left home to go to work during the reference week.
(For more information, see discussion under "Reference Week.")
Travel Time to Work--The data on travel time to work were derived from
answers to questionnaire item 24b. This question was asked of persons who
indicated in question 21 that they worked at some time during the
reference week and who reported in question 23a that they worked
outside their home. Travel time to work refers to the total number of
minutes that it usually took the person to get from home to work during
the reference week. The elapsed time includes time spent waiting for
public transportation, picking up passengers in carpools, and time
spent in other activities related to getting to work. (For more
information, see discussion under "Reference Week.")
LANGUAGE SPOKEN AT HOME AND ABILITY TO SPEAK ENGLISH
Language Spoken at Home--Data on language spoken at home were derived from
the answers to questionnaire items 15a and 15b, which were asked of a
sample of persons born before April 1, 1985. Instructions mailed with the
1990 census questionnaire stated that a respondent should mark "Yes"
in question 15a if the person sometimes or always spoke a language
other than English at home and should not mark "Yes" if a
language was spoken only at school or if speaking was limited to a few
expressions or slang. For question 15b, respondents were instructed to
print the name of the non-English language spoken at home. If the
person spoke more than one language other than English, the person was
to report the language spoken more often or the language learned first.
The cover of the census questionnaire included information in Spanish
which provided a telephone number for respondents to call to request a
census questionnaire and instructions in Spanish. Instruction guides
were also available in 32 other languages to assist enumerators who
encountered households or respondents who spoke no English.
Questions 15a and 15b referred to languages spoken at home in an effort
to measure the current use of languages other than English. Persons who
knew languages other than English but did not use them at home or who
only used them elsewhere were excluded. Persons who reported speaking a
language other than English at home may also speak English; however,
the questions did not permit determination of the main or dominant
language of persons who spoke both English and another language. (For
more information, see discussion below on "Ability to Speak
English.")
For persons who indicated that they spoke a language other than English
at home in question 15a, but failed to specify the name of the language
in question 15b, the language was assigned based on the language of
other speakers in the household; on the language of a person of the
same Spanish origin or detailed race group living in the same or a
nearby area; or on a person of the same ancestry or place of birth. In
all cases where a person was assigned a non-English language, it was
assumed that the language was spoken at home. Persons for whom the name
of a language other than English was entered in question 15b, and for
whom question 15a was blank were assumed to speak that language at
home.
The write-in responses listed in question 15b (specific language
spoken) were transcribed onto computer files and coded into more than
380 detailed language categories using an automated coding system. The
automated procedure compared write-in responses reported by respondents
with entries in a computer dictionary, which initially contained
approximately 2,000 language names. The dictionary was updated with a
large number of new names, variations in spelling, and a small number
of residual categories. Each write-in response was given a numeric code
that was associated with one of the detailed categories in the
dictionary. If the respondent listed more than one non-English
language, only the first was coded.
The write-in responses represented the names people used for languages
they speak. They may not match the names or categories used by
linguists. The sets of categories used are sometimes geographic and
sometimes linguistic. Figure 1 provides an illustration of the content
of the classification schemes used to present language data. For more
information, write to the Chief, Population Division, U.S. Bureau of
the Census, Washington, DC 20233.
Household Language--In households where one or more persons (age 5 years
old or over) speak a language other than English, the household language
assigned to all household members is the non-English language spoken by the
first person with a non-English language in the following order:
householder, spouse, parent, sibling,
child, grandchild, other relative, stepchild, unmarried partner,
housemate or roommate, roomer, boarder, or foster child, or other
nonrelative. Thus, persons who speak only English may have a
non-English household language assigned to them in tabulations of
persons by household language.
---------------------------------------------------------------------------
Figure 1. Four- and Twenty-Five-Group Classifications of 1990 Census
Languages Spoken at Home with Illustrative Examples
Four-Group Twenty-Five-Group Examples
Classification Classification
---------------------------------------------------------------------------
Spanish Spanish Spanish, Ladino
Other Indo- French French, Cajun,
European French Creole
Italian
Portuguese
German
Yiddish
Other West Afrikaans, Dutch,
Germanic Pennsylvania Dutch
Scandanavian Danish, Norwegian,
Swedish
Polish
Russian
South Slavic Serbocroatian,
Bulgarian, Macedonian,
Slovene
Other Slavic Czech, Slovak,
Ukranian
Greek
Indic Hindi, Bengali,
Gujarathi, Punjabi,
Romany, Sinhalese
Other Indo- Armenian, Gaelic,
European, not Lithuanian, Persian
elsewhere classified
Languages of Chinese
Asia and the Japanese
Pacific Mon-Khmer Cambodian
Tagalog
Korean
Vietnamese
Other languages Chamorro, Dravidian
(part) Languages, Hawaiian,
Ilocano, Thai, Turkish
All other lan- Arabic
guages Hungarian
Native North
American languages
Other languages Amharic, Syriac,
(part) Finnish, Hebrew,
Languages of
Central and South
America, Other
Languages of Africa
---------------------------------------------------------------------------
Ability to Speak English--Persons 5 years old and over who reported that
they spoke a language other than English in question 15a were also asked in
question 15c to indicate their ability to speak English based on one of the
following categories: "Very well," "Well," "Not well," or "Not at all."
The data on ability to speak English represent the person's own
perception about his or her own ability or, because census
questionnaires are usually completed by one household member, the
responses may represent the perception of another household member. The
instruction guides and questionnaires that were mailed to households
did not include any information on how to interpret the response
categories in question 15c.
Persons who reported that they spoke a language other than English
at home but whose ability to speak English was not reported, were
assigned the English-language ability of a randomly selected person of
the same age, Spanish origin, nativity and year of entry, and language
group.
Linguistic Isolation-- A household in which no person age 14 years or over
speaks only English and no person age 14 years or over who speaks a
language other than English speaks English "Very well" is classified as
"linguistically isolated." All the members of a linguistically isolated
household are tabulated as linguistically isolated, including members under
age 14 years who may speak only English.
Limitation of the Data--Persons who speak a language other than English at
home may have first learned that language at school. However, these persons
would be expected to indicate that they spoke English "Very well." Persons
who speak a language other than English, but do not do so at home, should
have been reported as not speaking a language other than English at home.
The extreme detail in which language names were coded may give a false
impression of the linguistic precision of these data. The names used by
speakers of a language to identify it may reflect ethnic, geographic,
or political affiliations and do not necessarily respect linguistic
distinctions. The categories shown in the tabulations were chosen on a
number of criteria, such as information about the number of speakers of
each language that might be expected in a sample of the United States
population.
Comparability--Information on language has been collected in every census
since 1890. The comparability of data among censuses is limited by changes
in question wording, by the subpopulations to whom the question was
addressed, and by the detail that was published.
The same question on language was asked in the 1980 and 1990 censuses.
This question on the current language spoken at home replaced the
questions asked in prior censuses on mother tongue; that is, the
language other than English spoken in the person's home when he or she
was a child; one's first language; or the language spoken before
immigrating to the United States. The censuses of 1910-1940, 1960 and
1970 included questions on mother tongue. A change in coding procedure
from 1980 to 1990 should have improved accuracy of coding and may
affect the number of persons reported in some of the 380 plus
categories. It should not greatly affect the 4-group or 25- group
lists. In 1980, coding clerks supplied numeric codes for the written
entries on each questionnaire using a 2,000 name reference list. In
1990 written entries were transcribed to a computer file and matched to
a computer dictionary which began with the 2,000 name list, but
expanded as unmatched names were referred to headquarters specialists
for resolution.
The question on ability to speak English was asked for the first time
in 1980. In tabulations from 1980, the categories "Very well" and
"Well" were combined. Data from other surveys suggested a major
difference between the category "Very well" and the remaining
categories. In tabulations showing ability to speak English, persons
who reported that they spoke English "Very well" are presented
separately from persons who reported their ability to speak English as
less than "Very well."
MARITAL STATUS--The data on marital status were derived from answers to
questionnaire item 6, which was asked of all persons. The marital
status classification refers to the status at the time of enumeration.
Data on marital status are tabulated only for persons 15 years old and
over.
All persons were asked whether they were "now married," "widowed,"
"divorced," "separated," or "never married." Couples who live together
(unmarried persons, persons in common-law marriages) were allowed to report
the marital status they considered the most appropriate.
Never Married--Includes all persons who have never been married, including
persons whose only marriage(s) was annulled.
Ever Married--Includes persons married at the time of enumeration
(including those separated), widowed, or divorced.
Now Married, Except Separated--Includes persons whose current marriage has
not ended through widowhood, divorce, or separation (regardless of previous
marital history). The category may also include couples who live together
or persons in common-law marriages if they consider this category the most
appropriate. In certain tabulations, currently married persons are
further classified as "spouse present" or "spouse absent."
Separated--Includes persons legally separated or otherwise absent from
their spouse because of marital discord. Included are persons who have been
deserted or who have parted because they no longer want to live
together but who have not obtained a divorce.
Widowed--Includes widows and widowers who have not remarried.
Divorced--Includes persons who are legally divorced and who have not
remarried.
In selected sample tabulations, data for married and separated persons are
reorganized and combined with information on the presence of the spouse in
the same household.
Now Married--All persons whose current marriage has not ended by widowhood
or divorce. This category includes persons defined above as "separated."
Spouse Present--Married persons whose wife or husband was enumerated as a
member of the same household, including those whose spouse may have been
temporarily absent for such reasons as travel or hospitalization.
Spouse Absent--Married persons whose wife or husband was not enumerated as
a member of the same household. This category also includes all married
persons living in group quarters.
Separated--Defined above.
Spouse Absent, Other--Married persons whose wife or husband was not
enumerated as a member of the same household, excluding separated. Included
is any person whose spouse was employed and living away from home or in an
institution or absent in the Armed Forces.
Differences between the number of currently married males and the
number of currently married females occur because of reporting
differences and because some husbands and wives have their usual
residence in different areas. In sample tabulations, these differences
can also occur because different weights are applied to the
individual's data. Any differences between the number of "now
married, spouse present" males and females are due solely to sample
weighting. By definition, the numbers would be the same.
When marital status was not reported, it was imputed according to the
relationship to the householder and sex and age of the person. (For
more information on imputation, see Appendix C, Accuracy of the Data.)
Comparability--The 1990 marital status definitions are the same as those
used in 1980 with the exception of the term "never married" which replaces
the term "single" in tabulations. A general marital status question
has been asked in every census since 1880.
MOBILITY LIMITATION STATUS--The data on mobility limitation status were
derived from answers to questionnaire item 19a, which was asked of a sample
of persons 15 years old and over. Persons were identified as having a
mobility limitation if they had a health condition that had lasted for 6 or
more months and which made it difficult to go outside the home alone.
Examples of outside activities on the questionnaire included shopping and
visiting the doctor's office.
The term "health condition" referred to both physical and mental
conditions. A temporary health problem, such as a broken bone that was
expected to heal normally, was not considered a health condition.
Comparability--This was the first time that a question on mobility
limitation was included in the census.
PLACE OF BIRTH--The data on place of birth were derived from answers to
questionnaire item 8, which was asked on a sample basis. The
place-of-birth question asked respondents to report the U.S. State,
commonwealth or territory, or the foreign country where they were born.
Persons born outside the United States were asked to report their place
of birth according to current international boundaries. Since numerous
changes in boundaries of foreign countries have occurred in the last
century, some persons may have reported their place of birth in terms
of boundaries that existed at the time of their birth or emigration, or
in accordance with their own national preference.
Persons not reporting place of birth were assigned the birthplace of
another family member or were allocated the response of another person
with similar characteristics. Persons allocated as foreign born were
not assigned a specific country of birth but were classified as
"Born abroad, country not specified."
Nativity--Information on place of birth and citizenship were used to
classify the population into two major categories: native and foreign born.
When information on place of birth was not reported, nativity was assigned
on the basis of answers to citizenship, if reported, and other
characteristics.
Native--Includes persons born in the United States, Puerto Rico, or an
outlying area of the United States. The small number of persons who were
born in a foreign country but have at least one American parent also are
included in this category.
The native population is classified in the following groups: persons
born in the State in which they resided at the time of the census;
persons born in a different State, by region; persons born in Puerto
Rico or an outlying area of the U.S.; and persons born abroad with at
least one American parent.
Foreign Born--Includes persons not classified as "Native." Prior to the
1970 census, persons not reporting place of birth were generally classified
as native.
The foreign-born population is shown by selected area, country, or
region of birth: the places of birth shown in data products were
selected based on the number of respondents who reported that area or
country of birth.
Comparability--Data on the State of birth of the native population have
been collected in each census beginning with that of 1850. Similar data
were shown in tabulations for the 1980 census and other recent censuses.
Nonresponse was allocated in a similar manner in 1980; however, prior to
1980, nonresponse to the place of birth question was not allocated. Prior
to the 1970 census, persons not reporting place of birth were generally
classified as native.
The questionnaire instruction to report mother's State of residence
instead of the person's actual State of birth (if born in a hospital
in a different State) was dropped in 1990. Evaluation studies of 1970
and 1980 census data demonstrated that this instruction was generally
either ignored or misunderstood. Since the hospital and the mother's
residence is in the same State for most births, this change may have a
slight effect on State of birth data for States with large metropolitan
areas that straddle State lines.
POVERTY STATUS IN 1989--The data on poverty status were derived from
answers to the same questions as the income data, questionnaire items 32
and 33. (For more information, see the discussion under "Income in 1989.")
Poverty statistics presented in census publications were based on a
definition originated by the Social Security Administration in 1964 and
subsequently modified by Federal interagency committees in 1969 and
1980 and prescribed by the Office of Management and Budget in Directive
14 as the standard to be used by Federal agencies for statistical
purposes.
At the core of this definition was the 1961 economy food plan, the
least costly of four nutritionally adequate food plans designed by the
Department of Agriculture. It was determined from the Agriculture
Department's 1955 survey of food consumption that families of three or
more persons spend approximately one-third of their income on food;
hence, the poverty level for these families was set at three times the
cost of the economy food plan. For smaller families and persons living
alone, the cost of the economy food plan was multiplied by factors that
were slightly higher to compensate for the relatively larger fixed
expenses for these smaller households.
The income cutoffs used by the Census Bureau to determine the poverty
status of families and unrelated individuals included a set of 48
thresholds arranged in a two-dimensional matrix consisting of family
size (from one person to nine or more persons) cross-classified by
presence and number of family members under 18 years old (from no
children present to eight or more children present). Unrelated
individuals and two-person families were further differentiated by age
of the householder (under 65 years old and 65 years old and over).
The total income of each family or unrelated individual in the sample
was tested against the appropriate poverty threshold to determine the
poverty status of that family or unrelated individual. If the total
income was less than the corresponding cutoff, the family or unrelated
individual was classified as "below the poverty level." The
number of persons below the poverty level was the sum of the number of
persons in families with incomes below the poverty level and the number
of unrelated individuals with incomes below the poverty level.
The poverty thresholds are revised annually to allow for changes in the
cost of living as reflected in the Consumer Price Index. The average
poverty threshold for a family of four persons was $12,674 in 1989.
(For more information, see table A below.) Poverty thresholds were
applied on a national basis and were not adjusted for regional, State
or local variations in the cost of living. For a detailed discussion of
the poverty definition, see U.S. Bureau of the Census, Current
Population Reports, Series P-60, No. 171, Poverty in the United
States: 1988 and 1989.
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Table A. Poverty Thresholds in 1989 by Size of Family and Number
of Related Children Under 18 Years
Weight Related children under 18 years
Size of average Eight
Family Unit thresholds None One Two Three Four Five Six Seven or more
---------------------------------------------------------------------------
One person
(unrelated
individual) $6,310
Under 65 yrs. 6 451 $6,451
65 yrs. &
over 5,947 5,947
Two persons 8,076
Householder
under 65 yrs. 8,343 8,303 $8,547
Householder
65 yrs. & over 7,501 7,495 8,515
Three persons 9,885 9,699 9,981 $9,990
Four persons 12,674 12,790 12,999 12,575 $12,619
Five persons 14,990 15,424 15,648 15,169 14,798 $14,572
Six persons 16,921 17,740 17,811 17,444 17,092 16,569 $16,259
Seven persons 19,162 20,412 20,540 20,101 19,794 19,224 18,558 $17,828
Eight persons 21,328 22,830 23,031 22,617 22,253 21,738 21,084 20,403 $20,230
Nine or
more persons 25,480 27,463 27,596 27,229 26,921 26,415 25,719 25,089 24,933 $23,973
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Persons for Whom Poverty Status is Determined-- Poverty status was
determined for all persons except institutionalized persons, persons in
military group quarters and in college dormitories, and unrelated
individuals under 15 years old. These groups also were excluded from the
denominator when calculating poverty rates.
Specified Poverty Levels--Since the poverty levels currently in use by the
Federal Government do not meet all the needs of data users, some of the
data are presented for alternate levels. These specified poverty levels are
obtained by multiplying the income cutoffs at the poverty level by the
appropriate factor. For example, the average income cutoff at 125 percent
of poverty level was $15,843 ($12,674 x 1.25) in 1989 for a family of four
persons.
Weighted Average Thresholds at the Poverty Level--The average thresholds
shown in the first column of table A are weighted by the presence and
number of children. For example, the weighted average threshold for a given
family size is obtained by multiplying the threshold for each presence and
number of children category within the given family size by the number of
families in that category. These products are then aggregated across the
entire range of presence and number of children categories, and the
aggregate is divided by the total number of families in the group to yield
the weighted average threshold at the poverty level for that family size.
Since the basic thresholds used to determine the poverty status of
families and unrelated individuals are applied to all families and
unrelated individuals, the weighted average poverty thresholds are
derived using all families and unrelated individuals rather than just
those classified as being below the poverty level. To obtain the
weighted poverty thresholds for families and unrelated individuals
below alternate poverty levels, the weighted thresholds shown in table
A may be multiplied directly by the appropriate factor. The weighted
average thresholds presented in the table are based on the March 1990
Current Population Survey. However, these thresholds would not differ
significantly from those based on the 1990 census.
Income Deficit--Represents the difference between the total income of
families and unrelated individuals below the poverty level and their
respective poverty thresholds. In computing the income deficit, families
reporting a net income loss are assigned zero dollars and for such cases
the deficit is equal to the poverty threshold.
This measure provided an estimate of the amount which would be required
to raise the incomes of all poor families and unrelated individuals to
their respective poverty thresholds. The income deficit is thus a
measure of the degree of impoverishment of a family or unrelated
individual. However, caution must be used in comparing the average
deficits of families with different characteristics. Apparent
differences in average income deficits may, to some extent, be a
function of differences in family size.
Mean Income Deficit--Represents the amount obtained by dividing the total
income deficit of a group below the poverty level by the number of families
(or unrelated individuals) in that group.
Comparability--The poverty definition used in the 1990 and 1980 censuses
differed slightly from the one used in the 1970 census. Three technical
modifications were made to the definition used in the 1970 census as
described below:
1. The separate thresholds for families with a female householder with
no husband present and all other families were eliminated. For the 1980
and 1990 censuses, the weighted average of the poverty thresholds for
these two types of families was applied to all types of families,
regardless of the sex of the householder.
2. Farm families and farm unrelated individuals no longer had a set of
poverty thresholds that were lower than the thresholds applied to
nonfarm families and unrelated individuals. The farm thresholds were 85
percent of the corresponding levels for nonfarm families in the 1970
census. The same thresholds were applied to all families and unrelated
individuals regardless of residence in 1980 and 1990.
3. The thresholds by size of family were extended from seven or more
persons in 1970 to nine or more persons in 1980 and 1990.
These changes resulted in a minimal increase in the number of poor
at the national level. For a complete discussion of these modifications
and their impact, see the Current Population Reports, Series P-60, No.
133.
The population covered in the poverty statistics derived from the 1980
and 1990 censuses was essentially the same as in the 1970 census. The
only difference was that in 1980 and 1990, unrelated individuals under
15 years old were excluded from the poverty universe, while in 1970,
only those under 14 years old were excluded. The poverty data from the
1960 census excluded all persons in group quarters and included all
unrelated individuals regardless of age. It was unlikely that these
differences in population coverage would have had significant impact
when comparing the poverty data for persons since the 1960 censuses.
Current Population Survey--Because of differences in the questionnaires and
data collection procedures, estimates of the number of persons below the
poverty level by various characteristics from the 1990 census may differ
from those reported in the March 1990 Current Population Survey.
RACE--The data on race were derived from answers to questionnaire item 4,
which was asked of all persons. The concept of race as used by the
Census Bureau reflects self-identification; it does not denote any
clear-cut scientific definition of biological stock. The data for race
represent self-classification by people according to the race with
which they most closely identify. Furthermore, it is recognized that
the categories of the race item include both racial and national origin
or socio-cultural groups.
During direct interviews conducted by enumerators, if a person could
not provide a single response to the race question, he or she was asked
to select, based on self-identification, the group which best described
his or her racial identity. If a person could not provide a single race
response, the race of the mother was used. If a single race response
could not be provided for the person's mother, the first race reported
by the person was used. In all cases where occupied housing units,
households, or families are classified by race, the race of the
householder was used.
The racial classification used by the Census Bureau generally adheres
to the guidelines in Federal Statistical Directive No. 15, issued by
the Office of Management and Budget, which provides standards on ethnic
and racial categories for statistical reporting to be used by all
Federal agencies. The racial categories used in the 1990 census data
products are provided below.
White--Includes persons who indicated their race as "White" or reported
entries such as Canadian, German, Italian, Lebanese, Near Easterner,
Arab, or Polish.
Black--Includes persons who indicated their race as "Black or Negro" or
reported entries such as African American, Afro-American, Black Puerto
Rican, Jamaican, Nigerian, West Indian, or Haitian.
American Indian, Eskimo, or Aleut--Includes persons who classified
themselves as such in one of the specific race categories identified below.
American Indian--Includes persons who indicated their race as "American
Indian," entered the name of an Indian tribe, or reported such entries as
Canadian Indian, French-American Indian, or Spanish-American Indian.
American Indian Tribe--Persons who identified themselves as American Indian
were asked to report their enrolled or principal tribe. Therefore, tribal
data in tabulations reflect the written tribal entries reported on the
questionnaires. Some of the entries (for example, Iroquois, Sioux, Colorado
River, and Flathead) represent nations or reservations.
The information on tribe is based on self-identification and therefore
does not reflect any designation of Federally- or State-recognized
tribe. Information on American Indian tribes is presented in summary
tape files and special data products. The information is derived from
the American Indian Detailed Tribal Classification List for the 1990
census. The classification list represents all tribes, bands, and clans
that had a specified number of American Indians reported on the census
questionnaire.
Eskimo--Includes persons who indicated their race as "Eskimo" or reported
entries such as Arctic Slope, Inupiat, and Yupik.
Aleut--Includes persons who indicated their race as "Aleut" or reported
entries such as Alutiiq, Egegik, and Pribilovian.
Asian or Pacific Islander--Includes persons who reported in one of the
Asian or Pacific Islander groups listed on the questionnaire or who
provided write-in responses such as Thai, Nepali, or Tongan. A more
detailed listing of the groups comprising the Asian or Pacific Islander
population is presented in figure 2 below. In some data products,
information is presented separately for the Asian population and the
Pacific Islander population.
Asian--Includes "Chinese," "Filipino," "Japanese," "Asian Indian,"
"Korean," "Vietnamese," and "Other Asian." In some tables, "Other Asian"
may not be shown separately, but is included in the total Asian population.
Chinese--Includes persons who indicated their race as "Chinese" or who
identified themselves as Cantonese, Tibetan, or Chinese American. In
standard census reports, persons who reported as "Taiwanese" or "Formosan"
are included here with Chinese. In special reports on the Asian or Pacific
Islander population, information on persons who identified themselves as
Taiwanese are shown separately.
Filipino--Includes persons who indicated their race as "Filipino" or
reported entries such as Philipino, Philipine, or Filipino American.
Japanese--Includes persons who indicated their race as "Japanese" and
persons who identified themselves as Nipponese or Japanese American.
Asian Indian--Includes persons who indicated their race as "Asian Indian"
and persons who identified themselves as Bengalese, Bharat, Dravidian, East
Indian, or Goanese.
Korean--Includes persons who indicated their race as "Korean" and persons
who identified themselves as Korean American.
Vietnamese--Includes persons who indicated their race as "Vietnamese" and
persons who identified themselves as Vietnamese American.
Cambodian--Includes persons who provided a write-in response such as
Cambodian or Cambodia.
Hmong--Includes persons who provided a write-in response such as Hmong,
Laohmong, or Mong.
Laotian--Includes persons who provided a write-in response such as Laotian,
Laos, or Lao.
Thai--Includes persons who provided a write-in response such as Thai,
Thailand, or Siamese.
Other Asian--Includes persons who provided a write-in response of
Bangladeshi, Burmese, Indonesian, Pakistani, Sri Lankan,
Amerasian, or Eurasian. See figure 2 for other groups comprising
"Other Asian."
Pacific Islander--Includes persons who indicated their race as "Pacific
Islander" by classifying themselves into one of the following groups or
identifying themselves as one of the Pacific Islander cultural groups
of Polynesian, Micronesian, or Melanesian.
Hawaiian--Includes persons who indicated their race as "Hawaiian" as well
as persons who identified themselves as Part Hawaiian or Native Hawaiian.
Samoan--Includes persons who indicated their race as "Samoan" or persons
who identified themselves as American Samoan or Western Samoan.
Guamanian--Includes persons who indicated their race as "Guamanian" or
persons who identified themselves as Chamorro or Guam.
Other Pacific Islander--Includes persons who provided a write-in response
of a Pacific Islander group such as Tahitian, Northern Mariana Islander,
Palauan, Fijian, or a cultural group such as Polynesian, Micronesian, or
Melanesian. See figure 2 for other groups comprising "Other Pacific
Islander."
Other Race--Includes all other persons not included in the "White,"
"Black," "American Indian, Eskimo, or Aleut," and the "Asian or Pacific
Islander" race categories described above.
Persons reporting in the "Other race" category and providing
write-in entries such as multiracial, multiethnic, mixed, interracial,
Wesort, or a Spanish/Hispanic origin group (such as Mexican, Cuban, or
Puerto Rican) are included here.
Written entries to three categories on the race item--"Indian (Amer.),"
"Other Asian or Pacific Islander (API)," and "Other race"--were reviewed,
edited, and coded by subject matter specialists. (For more information on
the coding operation, see the section below that discusses
"Comparability.")
The written entries under "Indian (Amer.)" and "Other Asian or
Pacific Islander (API)" were reviewed and coded during 100-percent
processing of the 1990 census questionnaires. A substantial portion of
the entries for the "Other race" category also were reviewed,
edited, and coded during the 100-percent processing. The remaining
entries under "Other race" underwent review and coding during
sample processing. Most of the written entries reviewed and coded
during sample processing were those indicating Hispanic origin such as
Mexican, Cuban, or Puerto Rican.
If the race entry for a member of a household was missing on the
questionnaire, race was assigned based upon the reported entries of
race by other household members using specific rules of precedence of
household relationship. For example, if race was missing for the
daughter of the householder, then the race of her mother (as female
householder or female spouse) would be assigned. If there was no female
householder or spouse in the household, the daughter would be assigned
her father's (male householder) race. If race was not reported for
anyone in the household, the race of a householder in a previously
processed household was assigned. This procedure is a variation of the
general imputation procedures described in Appendix C, Accuracy of the
Data.
Limitation of the Data--In the 1980 census, a relatively high proportion
(20 percent) of American Indians did not report any tribal entry in the
race item. Evaluation of the pre-census tests indicated that changes made
for the 1990 race item should improve the reporting of tribes in the rural
areas (especially on reservations) for the 1990 census. The results for
urban areas were inconclusive. Also, the precensus tests indicated that
there may be overreporting of the Cherokee tribe. An evaluation of 1980
census data showed overreporting of Cherokee in urban areas or areas
where the number of American Indians was sparse.
In the 1990 census, respondents sometimes did not fill in a circle or
filled the "Other race" circle and wrote in a response, such as
Arab, Polish, or African American in the shared write-in box for
"Other race" and "Other API" responses. During the automated coding
process, these responses were edited and assigned to the appropriate racial
designation. Also, some Hispanic origin persons did not fill in a circle,
but provided entries such as Mexican or Puerto Rican. These persons were
classified in the "Other race" category during the coding and editing
process. There may be some minor differences between sample data and 100-
percent data because sample processing included additional edits not
included in the 100-percent processing.
Figure 2. Asian or Pacific Islander Groups Reported in the 1990 Census
Asian Pacific Islander
Chinese Hawaiian
Filipino Samoan
Japanese Guamanian
Asian Indian Other Pacific Islander(1)
Korean Carolinian
Vietnamese Fijian
Cambodian Kosraean
Hmong Melanesian(3)
Laotian Micronesian(3)
Thai Northern Mariana Islander
Other Asian(1) Palauan
Bangladeshi Papua New Guinean
Bhutanese Ponapean (Pohnpeian)
Borneo Polynesian(3)
Burmese Solomon Islander
Celebesian Tahitian
Ceram Tarawa Islander
Indochinese Tokelauan
Indonesian Tongan
Iwo-Jiman Trukese (Chuukese)
Javanese Yapese
Malayan Pacific Islander, not specified
Maldivian
Nepali
Okinawan
Pakistani
Sikkim
Singaporean
Sri Lankan
Sumatran
Asian, not specified(2)
---------------------------------------------------------------------------
(1)In some data products, specific groups listed under "Other Asian" or
"Other Pacific Islander" are shown separately. Groups not shown are
tabulated as "All other Asian" or "All other Pacific Islander,"
respectively.
(2)Includes entries such as Asian American, Asian, Asiatic, Amerasian, and
Eurasian.
(3)Polynesian, Micronesian, and Melanesian are Pacific Islander cultural
groups.
Comparability--Differences between the 1990 census and earlier censuses
affect the comparability of data for certain racial groups and American
Indian tribes. The 1990 census was the first census to undertake, on a 100-
percent basis, an automated review, edit, and coding operation for
written responses to the race item. The automated coding system used in
the 1990 census greatly reduced the potential for error associated with
a clerical review. Specialists with a thorough knowledge of the race
subject matter reviewed, edited, coded, and resolved inconsistent or
incomplete responses. In the 1980 census, there was only a limited
clerical review of the race responses on the 100-percent forms with a
full clerical review conducted only on the sample questionnaires.
Another major difference between the 1990 and preceding censuses is the
handling of the write-in responses for the Asian or Pacific Islander
populations. In addition to the nine Asian or Pacific Islander
categories shown on the questionnaire under the spanner "Asian or
Pacific Islander (API)," the 1990 census race item provided a new
residual category, "Other API," for Asian or Pacific Islander
persons who did not report in one of the listed Asian or Pacific
Islander groups. During the coding operation, write-in responses for
"Other API" were reviewed, coded, and assigned to the appropriate
classification. For example, in 1990, a write-in entry of Laotian,
Thai, or Javanese is classified as "Other Asian," while a
write-in entry of Tongan or Fijian is classified as "Other Pacific
Islander." In the 1990 census, these persons were able to identify
as "Other API" in both the 100-percent and sample operations.
In the 1980 census, the nine Asian or Pacific Islander groups were also
listed separately. However, persons not belonging to these nine groups
wrote in their specific racial group under the "Other" race
category. Persons with a written entry such as Laotian, Thai, or
Tongan, were tabulated and published as "Other race" in the 100-
percent processing operation in 1980, but were reclassified as "Other
Asian and Pacific Islander" in 1980 sample tabulations. In 1980
special reports on the Asian or Pacific Islander populations, data were
shown separately for "Other Asian" and "Other Pacific Islander."
The 1970 questionnaire did not have separate race categories for Asian
Indian, Vietnamese, Samoan, and Guamanian. These persons indicated
their race in the "Other" category and later, through the editing
process, were assigned to a specific group. For example, in 1970, Asian
Indians were reclassified as "White," while Vietnamese,
Guamanians, and Samoans were included in the "Other" category.
Another difference between 1990 and preceding censuses is the approach
taken when persons of Spanish/Hispanic origin did not report in a
specific race category but reported as "Other race" or "Other." These
persons commonly provided a write-in entry such as Mexican, Venezuelan, or
Latino. In the 1990 and 1980 censuses, these entries remained in the "Other
race" or "Other" category, respectively. In the 1970 census, most of these
persons were included in the "White" category.
REFERENCE WEEK
The data on labor force status and journey to work were related to
the reference week; that is, the calendar week preceding the date on
which the respondents completed their questionnaires or were
interviewed by enumerators. This week is not the same for all
respondents since the enumeration was not completed in one week. The
occurrence of holidays during the enumeration period could affect the
data on actual hours worked during the reference week, but probably had
no effect on overall measurement of employment status (see the
discussion below on "Comparability").
Comparability--The reference weeks for the 1990 and 1980 censuses differ in
that Passover and Good Friday occurred in the first week of April 1980, but
in the second week of April 1990. Many workers presumably took time off
for those observances. The differing occurrence of these holidays could
affect the comparability of the 1990 and 1980 data on actual hours
worked for some areas if the respective weeks were the reference weeks
for a significant number of persons. The holidays probably did not
affect the overall measurement of employment status since this
information was based on work activity during the entire reference
week.
RESIDENCE IN 1985
The data on residence in 1985 were derived from answers to question
14b, which asked for the State (or foreign country), county, and place
of residence on April 1, 1985, for those persons reporting in question
14a that on that date they lived in a different house than their
current residence. Residence in 1985 is used in conjunction with
location of current residence to determine the extent of residential
mobility of the population and the resulting redistribution of the
population across the various States, metropolitan areas, and regions
of the country.
When no information on residence in 1985 was reported for a person,
information for other family members, if available, was used to assign
a location of residence in 1985. All cases of nonresponse or incomplete
response that were not assigned a previous residence based on
information from other family members were allocated the previous
residence of another person with similar characteristics who provided
complete information.
The tabulation category, "Same house," includes all persons 5 years old and
over who did not move during the 5 years as well as those who had moved but
by 1990 had returned to their 1985 residence. The category, "Different
house in the United States," includes persons who lived in the United
States in 1985 but in a different house or apartment from the one they
occupied on April 1, 1990. These movers are then further subdivided
according to the type of move.
In most tabulations, movers are divided into three groups according to
their 1985 residence: "Different house, same county," "Different county,
same State," and "Different State." The last group may be further
subdivided into region of residence in 1985. The category, "Abroad,"
includes those persons who were residing in a foreign country, Puerto Rico,
or an outlying area of the U.S. in 1985, including members of the Armed
Forces and their dependents. Some tabulations show movers who were residing
in Puerto Rico or an outlying area in 1985 separately from those residing
in other countries.
In tabulations for metropolitan areas, movers are categorized according
to the metropolitan status of their current and previous residences,
resulting in such groups as movers within an MSA/PMSA, movers between
PMSA's, movers from nonmetropolitan areas to MSA/PMSA, and movers from
central cities to the remainder of an MSA/PMSA. In some tabulations,
these categories are further subdivided by size of MSA/PMSA, region of
current or previous residence, or movers within or between central
cities and the remainder of the same or a different MSA/PMSA.
The size categories used in some tabulations for both 1985 and 1990
residence refer to the populations of the MSA/PMSA on April 1, 1990;
that is, at the end of the migration interval.
Some tabulations present data on inmigrants, outmigrants, and net
migration. "Inmigrants" are generally defined as those persons
who entered a specified area by crossing its boundary from some point
outside the area. In some tabulations, movers from abroad are included
in the number of inmigrants; in others, only movers within the United
States are included.
"Outmigrants" are persons who depart from a specific area by
crossing its boundary to a point outside it, but without leaving the
United States. "Net migration" is calculated by subtracting the
number of outmigrants from the number of inmigrants and, depending upon
the particular tabulation, may or may not include movers from abroad.
The net migration for the area is net inmigration if the result was
positive and net outmigration if the result was negative. In the
tabulations, net outmigration is indicated by a minus sign (-).
Inmigrants and outmigrants for States include only those persons who
did not live in the same State in 1985 and 1990; that is, they exclude
persons who moved between counties within the same State. Thus, the sum
of the inmigrants to (or outmigrants from) all counties in any State is
greater than the number of inmigrants to (or outmigrants from) that
State. However, in the case of net migration, the sum of the nets for
all the counties within a State equal the net for the State. In the
same fashion, the net migration for a division or region equals the sum
of the nets for the States comprising that division or region, while
the number of inmigrants and outmigrants for that division or region is
less than the sum of the inmigrants or outmigrants for the individual
States.
The number of persons who were living in a different house in 1985 is
somewhat less than the total number of moves during the 5-year period.
Some persons in the same house at the two dates had moved during the
5-year period but by the time of the census had returned to their 1985
residence. Other persons who were living in a different house had made
one or more intermediate moves. For similar reasons, the number of
persons living in a different county, MSA/PMSA, or State or moving
between nonmetropolitan areas may be understated.
Comparability--Similar questions were asked on all previous censuses
beginning in 1940, except the questions in 1950 referred to residence 1
year earlier rather than 5 years earlier. Although the questions in the
1940 census covered a 5-year period, comparability with that census was
reduced somewhat because of different definitions and categories of
tabulation. Comparability with the 1960 and 1970 census is also somewhat
reduced because nonresponse was not allocated in those earlier censuses.
For the 1980 census, nonresponse was allocated in a manner similar to the
1990 allocation scheme.
SCHOOL ENROLLMENT AND LABOR FORCE STATUS
Tabulation of data on enrollment, educational attainment, and labor
force status for the population 16 to 19 years old allows for
calculation of the proportion of the age group who are not enrolled in
school and not high school graduates or "dropouts" and an
unemployment rate for the "dropout" population. Definitions of
the three topics and descriptions of the census items from which they
were derived are presented in "Educational Attainment," "Employment
Status," and "School Enrollment and Type of School." The published
tabulations include both the civilian and Armed Forces populations, but
labor force status is provided for the civilian population only. Therefore,
the component labor force statuses may not add to the total lines enrolled
in school, high school graduate, and not high school graduate. The
difference is Armed Forces.
Comparability--The tabulation of school enrollment by labor force status is
similar to that published in 1980 census reports. The 1980 census
tabulation included a single data line for Armed Forces; however,
enrollment, attainment, and labor force status data were shown for the
civilian population only. In 1970, a tabulation was included for 16 to 21
year old males not attending school.
SCHOOL ENROLLMENT AND TYPE OF SCHOOL
Data on school enrollment were derived from answers to questionnaire
item 11, which was asked of a sample of persons. Persons were
classified as enrolled in school if they reported attending a
"regular" public or private school or college at any time between
February 1, 1990, and the time of enumeration. The question included
instructions to "include only nursery school, kindergarten,
elementary school, and schooling which would lead to a high school
diploma or a college degree" as regular school. Instructions
included in the 1990 respondent instruction guide, which was mailed
with the census questionnaire, further specified that enrollment in a
trade or business school, company training, or tutoring were not to be
included unless the course would be accepted for credit at a regular
elementary school, high school, or college. Persons who did not answer
the enrollment question were assigned the enrollment status and type of
school of a person with the same age, race or Hispanic origin, and, at
older ages, sex, whose residence was in the same or a nearby area.
Public and Private School--Includes persons who attended school in the
reference period and indicated they were enrolled by marking one of the
questionnaire categories for either "public school, public college" or
"private school, private college." The instruction guide defines
a public school as "any school or college controlled and supported
by a local, county, State, or Federal Government." "Schools
supported and controlled primarily by religious organizations or other
private groups" are defined as private. Persons who filled both the
"public" and "private" circles are edited to the first entry, "public."
Level of School in Which Enrolled--Persons who were enrolled in school were
classified as enrolled in "preprimary school," "elementary or high school,"
or "college" according to their response to question 12 (years of school
completed or highest degree received). Persons who were enrolled and
reported completing nursery school or less were classified as enrolled in
"preprimary school," which includes kindergarten. Similarly, enrolled
persons who had completed at least kindergarten, but not high school, were
classified as enrolled in elementary or high school. Enrolled persons who
reported completing high school or some college or having received a post-
secondary degree were classified as enrolled in "college." Enrolled persons
who reported completing the twelfth grade but receiving "NO DIPLOMA" were
classified as enrolled in high school. (For more information on level of
school, see the discussion under "Educational Attainment.")
Comparability--School enrollment questions have been included in the census
since 1840; grade attended was first asked in 1940; type of school was
first asked in 1960. Before 1940, the enrollment question in various
censuses referred to attendance in the preceding six months or the
preceding year. In 1940, the reference was to attendance in the month
preceding the census, and in the 1950 and subsequent censuses, the question
referred to attendance in the two months preceding the census date.
Until the 1910 census, there were no instructions limiting the kinds of
schools in which enrollment was to be counted. Starting in 1910, the
instructions indicated that attendance at "school, college, or any
educational institution" was to be counted. In 1930 an instruction
to include "night school" was added. In the 1940 instructions,
night school, extension school, or vocational school were included only
if the school was part of the regular school system. Correspondence
school work of any kind was excluded. In the 1950 instructions, the
term "regular school" was introduced, and it was defined as
schooling which "advances a person towards an elementary or high
school diploma or a college, university, or professional school
degree." Vocational, trade, or business schools were excluded unless
they were graded and considered part of a regular school system.
On-the-job training was excluded, as was nursery school. Instruction by
correspondence was excluded unless it was given by a regular school and
counted towards promotion.
In 1960, the question used the term "regular school or college"
and a similar, though expanded, definition of "regular" was
included in the instructions, which continued to exclude nursery
school. Because of the census' use of mailed questionnaires, the 1960
census was the first in which instructions were written for the
respondent as well as enumerators. In the 1970 census, the
questionnaire used the phrase "regular school or college" and
included instructions to "count nursery school, kindergarten, and
schooling which leads to an elementary school certificate, high school
diploma, or college degree." Instructions in a separate document
specified that to be counted as regular school, nursery school must
include instruction as an important and integral phase of its program,
and continued the exclusion of vocational, trade, and business schools.
The 1980 census question was very similar to the 1970 question, but the
separate instruction booklet did not require that nursery school
include substantial instructional content in order to be counted.
The age range for which enrollment data have been obtained and
published has varied over the censuses. Information on enrollment was
recorded for persons of all ages in the 1930 and 1940 and 1970 through
1990; for persons under age 30, in 1950; and for persons age 5 to 34,
in 1960. Most of the published enrollment figures referred to persons
age 5 to 20 in the 1930 census, 5 to 24 in 1940, 5 to 29 in 1950, 5 to
34 in 1960, 3 to 34 in 1970, and 3 years old and over in 1980. This
growth in the age group whose enrollment was reported reflects
increased interest in the number of children in preprimary schools and
in the number of older persons attending colleges and universities.
In the 1950 and subsequent censuses, college students were enumerated
where they lived while attending college, whereas in earlier censuses,
they generally were enumerated at their parental homes. This change
should not affect the comparability of national figures on college
enrollment since 1940; however, it may affect the comparability over
time of enrollment figures at sub-national levels.
Type of school was first introduced in the 1960 census, where a
separate question asked the enrolled persons whether they were in a
"public" or "private" school. Since the 1970 census, the
type of school was incorporated into the response categories for the
enrollment question and the terms were changed to "public,"
"parochial," and "other private." In the 1980 census,
"private, church related" and "private, not church related"
replaced "parochial" and "other private."
Grade of enrollment was first available in the 1940 census, where it
was obtained from responses to the question on highest grade of school
completed. Enumerators were instructed that "for a person still in
school, the last grade completed will be the grade preceding the one in
which he or she was now enrolled." From 1950 to 1980, grade of
enrollment was obtained from the highest grade attended in the two-part
question used to measure educational attainment. (For more information,
see the discussion under "Educational Attainment.") The form of
the question from which level of enrollment was derived in the 1990
census most closely corresponds to the question used in 1940. While
data from prior censuses can be aggregated to provide levels of
enrollment comparable to the 1990 census, 1990 data cannot be
disaggregated to show single grade of enrollment as in previous
censuses.
Data on school enrollment were also collected and published by other
Federal, State, and local government agencies. Where these data were
obtained from administrative records of school systems and institutions
of higher learning, they were only roughly comparable with data from
population censuses and household surveys because of differences in
definitions and concepts, subject matter covered, time references, and
enumeration methods. At the local level, the difference between the
location of the institution and the residence of the student may affect
the comparability of census and administrative data. Differences
between the boundaries of school districts and census geographic units
also may affect these comparisons.
SELF-CARE LIMITATION STATUS
The data on self-care limitation status were derived from answers to
questionnaire item 19b, which was asked of a sample of persons 15 years
old and over. Persons were identified as having a self-care limitation
if they had a health condition that had lasted for 6 or more months and
which made it difficult to take care of their own personal needs, such
as dressing, bathing, or getting around inside the home.
The term "health condition" referred to both physical and mental
conditions. A temporary health problem, such as a broken bone that was
expected to heal normally was not considered a health condition.
Comparability--This was the first time that a question on self-care
limitation was included in the census.
SEX
The data on sex were derived from answers to questionnaire item 3,
which was asked of all persons. For most cases in which sex was not
reported, it was determined by the appropriate entry from the person's
given name and household relationship. Otherwise, sex was imputed
according to the relationship to the householder and the age and
marital status of the person. For more information on imputation, see
Appendix C, Accuracy of the Data.
Sex Ratio--A measure derived by dividing the total number of males by the
total number of females and multiplying by 100.
Comparability--A question on the sex of individuals has been asked of the
total population in every census.
VETERAN STATUS
Data on veteran status, period of military service, and years of
military service were derived from answers to questionnaire item 17,
which was asked of a sample of persons.
Veteran Status--The data on veteran status were derived from responses to
question 17a. For census data products, a "civilian veteran" is a person
16 years old or over who had served (even for a short time) but is not now
serving on active duty in the U.S. Army, Navy, Air Force, Marine Corps,
or the Coast Guard, or who served as a Merchant Marine seaman during
World War II. Persons who served in the National Guard or military
Reserves are classified as veterans only if they were ever called or
ordered to active duty not counting the 4-6 months for initial training
or yearly summer camps. All other civilians 16 years old and over are
classified as nonveterans.
Period of Military Service--Persons who indicated in question 17a that they
had served on active duty (civilian veterans) or were now on active duty
were asked to indicate in question 17b the period or periods in which they
served. Persons serving in at least one wartime period are classified in
their most recent wartime period. For example, persons who served both
during the Korean conflict and the post-Korean peacetime era between
February 1955 and July 1964 are classified in one of the two "Korean
conflict" categories. If the same person had also served during the
Vietnam era, he or she would instead be included in the "Vietnam era
and Korean conflict" category. The responses were edited to
eliminate inconsistencies between reported period(s) of service and the
age of the person and to cancel out reported combinations of periods
containing unreasonable gaps (for example, a person could not serve
during World War I and the Korean conflict without serving during World
War II). Note that the period of service categories shown in this
report are mutually exclusive.
Years of Military Service--Persons who indicated in question 17a that they
had served on active duty (civilian veterans) or were now on active duty
were asked to report the total number of years of active-duty service in
question 17c. The data were edited for consistency with responses to
question 17b (Period of Military Service) and with the age of the person.
Limitation of the Data--There may be a tendency for the following kinds of
persons to report erroneously that they served on active duty in the Armed
Forces: (a) persons who served in the National Guard or military Reserves
but were never called to active duty; (b) civilian employees or volunteers
for the USO, Red Cross, or the Department of Defense (or its predecessor
Departments, War and Navy); and (c) employees of the Merchant Marine or
Public Health Service. There may also be a tendency for persons to
erroneously round up months to the nearest year in question 17c (for
example, persons with 1 year 8 months of active duty military service
may mistakenly report "2 years").
Comparability--Since census data on veterans were based on self-reported
responses, they may differ from data from other sources such as
administrative records of the Department of Defense. Census data may also
differ from Veterans Administration data on the benefits-eligible
population, since factors determining eligibility for veterans benefits
differ from the rules for classifying veterans in the census.
The wording of the question on veteran status (17a) for 1990 was
expanded from the veteran/not veteran question in 1980 to include
questions on current active duty status and service in the military
Reserves and the National Guard. The expansion was intended to clarify
the appropriate response for persons in the Armed Forces and for
persons who served in the National Guard or military Reserve units
only. For the first time in a census, service during World War II as a
Merchant Marine Seaman was considered active-duty military service and
persons with such service were counted as veterans. An additional
period of military service, "September 1980 or later" was added
in 1990. As in 1970 and 1980, persons reporting more than one period of
service are shown in the most recent wartime period of service
category. Question 17c (Years of Military Service) was new for 1990.
WORK DISABILITY STATUS
The data on work disability were derived from answers to questionnaire item
18, which was asked of a sample of persons 15 years old and over. Persons
were identified as having a work disability if they had a health condition
that had lasted for 6 or more months and which limited the kind or amount
of work they could do at a job or business. A person was limited in the
kind of work he or she could do if the person had a health condition which
restricted his or her choice of jobs. A person was limited in the amount of
work if he or she was not able to work full-time. Persons with a work
disability were further classified as "Prevented from working" or "Not
prevented from working."
The term "health condition" referred to both physical and mental
conditions. A temporary health problem, such as a broken bone that was
expected to heal normally, was not considered a health condition.
Comparability--The wording of the question on work disability
was the same in 1990 as in 1980. Information on work disability was
first collected in 1970. In that census, the work disability question
did not contain a clause restricting the definition of disability to
limitations caused by a health condition that had lasted 6 or more
months; however, it did contain a separate question about the duration
of the disability.
WORK STATUS IN 1989
The data on work status in 1989 were derived from answers to
questionnaire item 31, which was asked of a sample of persons. Persons
16 years old and over who worked 1 or more weeks according to the
criteria described below are classified as "Worked in 1989." All
other persons 16 years old and over are classified as "Did not work
in 1989." Some tabulations showing work status in 1989 include 15
year olds; these persons, by definition, are classified as "Did not
work in 1989."
Weeks Worked in 1989
The data on weeks worked in 1989 were derived from responses to
questionnaire item 31b. Question 31b (Weeks Worked in 1989) was asked
of persons 16 years old and over who indicated in question 31a that
they worked in 1989.
The data pertain to the number of weeks during 1989 in which a person
did any work for pay or profit (including paid vacation and paid sick
leave) or worked without pay on a family farm or in a family business.
Weeks of active service in the Armed Forces are also included.
Usual Hours Worked Per Week Worked in 1989
The data on usual hours worked per week worked in 1989 were derived
from answers to questionnaire item 31c. This question was asked of
persons 16 years old and over who indicated that they worked in 1989.
The data pertain to the number of hours a person usually worked during
the weeks worked in 1989. The respondent was to report the number of
hours worked per week in the majority of the weeks he or she worked in
1989. If the hours worked per week varied considerably during 1989, the
respondent was to report an approximate average of the hours worked per
week. The statistics on usual hours worked per week in 1989 are not
necessarily related to the data on actual hours worked during the
census reference week (question 21b).
Persons 16 years old and over who reported that they usually worked 35
or more hours each week during the weeks they worked are classified as
"Usually worked full time;" persons who reported that they
usually worked 1 to 34 hours are classified as "Usually worked part
time."
Year-Round Full-Time Workers--All persons 16 years old and over who usually
worked 35 hours or more per week for 50 to 52 weeks in 1989.
Number of Workers in Family in 1989--The term "worker" as used for these
data is defined based on the criteria for Work Status in 1989.
Limitation of the Data--It is probable that the number of persons who
worked in 1989 and the number of weeks worked are understated since there
was some tendency for respondents to forget intermittent or short periods
of employment or to exclude weeks worked without pay. There may also be a
tendency for persons not to include weeks of paid vacation among their
weeks worked; one result may be that the census figures may understate the
number of persons who worked "50 to 52 weeks."
Comparability--The data on weeks worked collected in the 1990 census were
comparable with data from the 1980, 1970, and 1960 censuses, but may not be
entirely comparable with data from the 1940 and 1950 censuses. Since
the 1960 census, two separate questions have been used to obtain this
information. The first identified persons with any work experience
during the year and, thus, indicated those persons for whom the
questions on number of weeks worked applied. In 1940 and 1950, however,
the questionnaires contained only a single question on number of weeks
worked.
In 1970, persons responded to the question on weeks worked by
indicating one of six weeks-worked intervals. In 1980 and 1990, persons
were asked to enter the specific number of weeks they worked.
YEAR OF ENTRY
The data on year of entry were derived from answers to questionnaire
item 10, which was asked of a sample of persons. The question, "When
did this person come to the United States to stay?" was asked of
persons who indicated in the question on citizenship that they were not
born in the United States. (For more information, see the discussion
under "Citizenship.")
The 1990 census questions, tabulations, and census data products about
citizenship and year of entry include no reference to immigration. All
persons who were born and resided outside the United States before
becoming residents of the United States have a date of entry. Some of
these persons are U.S. citizens by birth (e.g., persons born in Puerto
Rico or born abroad of American parents). To avoid any possible
confusion concerning the date of entry of persons who are U.S. citizens
by birth, the term, "year of entry" is used in this report
instead of the term "year of immigration."
Limitation of the Data--The census questions on nativity, citizenship, and
year of entry were not designed to measure the degree of permanence of
residence in the United States. The phrase, "to stay" was used to obtain
the year in which the person became a resident of the United States.
Although the respondent was directed to indicate the year he or she entered
the country "to stay," it was difficult to ensure that respondents
interpreted the phrase correctly.
Comparability--A question on year of entry, (alternately called "year of
immigration") was asked in each decennial census from 1890 to 1930,
1970, and 1980. In 1980, the question on year of entry included six
arrival time intervals. The number of arrival intervals was expanded to
ten in 1990. In 1980, the question on year of entry was asked only of
the foreign-born population. In 1990, all persons who responded to the
long-form questionnaire and were not born in the United States were to
complete the question on year of entry.
HOUSING CHARACTERISTICS
LIVING QUARTERS
Living quarters are classified as either housing units or group
quarters. (For more information, see the discussion of "Group
Quarters" under Population Characteristics.) Usually, living
quarters are in structures intended for residential use (for example, a
one-family home, apartment house, hotel or motel, boarding house, or
mobile home). Living quarters also may be in structures intended for
nonresidential use (for example, the rooms in a warehouse where a guard
lives), as well as in places such as tents, vans, shelters for the
homeless, dormitories, barracks, and old railroad cars.
Housing Units--A housing unit is a house, an apartment, a mobile home or
trailer, a group of rooms or a single room occupied as separate living
quarters or, if vacant, intended for occupancy as separate living quarters.
Separate living quarters are those in which the occupants live and eat
separately from any other persons in the building and which have direct
access from outside the building or through a common hall.
The occupants may be a single family, one person living alone, two or
more families living together, or any other group of related or
unrelated persons who share living arrangements. For vacant units, the
criteria of separateness and direct access are applied to the intended
occupants whenever possible. If that information cannot be obtained,
the criteria are applied to the previous occupants.
Both occupied and vacant housing units are included in the housing unit
inventory, except that recreational vehicles, boats, vans, tents,
railroad cars, and the like are included only if they are occupied as
someone's usual place of residence. Vacant mobile homes are included
provided they are intended for occupancy on the site where they stand.
Vacant mobile homes on dealers' sales lots, at the factory, or in
storage yards are excluded from the housing inventory.
If the living quarters contains nine or more persons unrelated to the
householder or person in charge (a total of at least 10 unrelated
persons), it is classified as group quarters. If the living quarters
contains eight or fewer persons unrelated to the householder or person
in charge, it is classified as a housing unit.
Occupied Housing Units--A housing unit is classified as occupied if it is
the usual place of residence of the person or group of persons living in it
at the time of enumeration, or if the occupants are only temporarily
absent; that is, away on vacation or business. If all the persons staying
in the unit at the time of the census have their usual place of residence
elsewhere, the unit is classified as vacant. A household includes all the
persons who occupy a housing unit as their usual place of residence. By
definition, the count of occupied housing units for 100-percent
tabulations is the same as the count of households or householders. In
sample tabulations, the counts of household and occupied housing units
may vary slightly because of different sample weighting methods.
Vacant Housing Units--A housing unit is vacant if no one is living in it at
the time of enumeration, unless its occupants are only temporarily absent.
Units temporarily occupied at the time of enumeration entirely by persons
who have a usual residence elsewhere also are classified as vacant. (For
more information, see discussion under "Usual Home Elsewhere.")
New units not yet occupied are classified as vacant housing units if
construction has reached a point where all exterior windows and doors
are installed and final usable floors are in place. Vacant units are
excluded if they are open to the elements; that is, the roof, walls,
windows, and/or doors no longer protect the interior from the elements,
or if there is positive evidence (such as a sign on the house or in the
block) that the unit is condemned or is to be demolished. Also excluded
are quarters being used entirely for nonresidential purposes, such as a
store or an office, or quarters used for the storage of business
supplies or inventory, machinery, or agricultural products.
Hotels, Motels, Rooming Houses, Etc.--Occupied rooms or suites of rooms in
hotels, motels, and similar places are classified as housing units only
when occupied by permanent residents; that is, persons who consider the
hotel as their usual place of residence or have no usual place of residence
elsewhere. Vacant rooms or suites of rooms are classified as housing units
only in those hotels, motels, and similar places in which 75 percent or
more of the accommodations are occupied by permanent residents.
If any of the occupants in a rooming or boarding house live and eat
separately from others in the building and have direct access, their
quarters are classified as separate housing units.
Staff Living Quarters--The living quarters occupied by staff personnel
within any group quarters are separate housing units if they satisfy the
housing unit criteria of separateness and direct access; otherwise, they
are considered group quarters.
Comparability--The first Census of Housing in 1940 established the
"dwelling unit" concept. Although the term became "housing unit" and the
definition has been modified slightly in succeeding censuses, the 1990
definition is essentially comparable to previous censuses. There was no
change in the housing unit definition between 1980 and 1990.
ACREAGE
The data on acreage were obtained from questionnaire items H5a and
H19a. Question H5a was asked at all occupied and vacant one-family
houses and mobile homes. Question H19a was asked on a sample basis at
occupied and vacant one-family houses and mobile homes.
Question H5a asks whether the house or mobile home is located on a
place of 10 or more acres. The intent of this item is to exclude
owner-occupied and renter-occupied one-family houses on 10 or more
acres from the specified owner- and renter-occupied universes for value
and rent tabulations.
Question H19a provides data on whether the unit is located on less than
1 acre. The main purpose of this item, in conjunction with question
H19b on agricultural sales, is to identify farm units. (For more
information, see discussion under "Farm Residence.")
For both items, the land may consist of more than one tract or plot.
These tracts or plots are usually adjoining; however, they may be
separated by a road, creek, another piece of land, etc.
Comparability--
Question H5a is similar to that asked in 1970 and 1980. This item was
asked for the first time of mobile home occupants in 1990. Question
H19a is an abbreviated form of a question asked on a sample basis in
1980. In previous censuses, information on city or suburban lot and
number of acres was obtained also.
AGRICULTURAL SALES
Data on the sales of agricultural crops were obtained from
questionnaire item H19b, which was asked on a sample basis at occupied
one-family houses and mobile homes located on lots of 1 acre or more.
Data for this item exclude units on lots of less than 1 acre, units
located in structures containing 2 or more units, and all vacant units.
This item refers to the total amount (before taxes and expenses)
received in 1989 from the sale of crops, vegetables, fruits, nuts,
livestock and livestock products, and nursery and forest products,
produced on "this property." Respondents new to a unit were asked
to estimate total agricultural sales in 1989 even if some portion of
the sales had been made by other occupants of the unit.
This item is used mainly to classify housing units as farm or nonfarm
residences, not to provide detailed information on the sale of
agricultural products. Detailed information on the sale of agricultural
products is provided by the Census Bureau's Census of Agriculture
(Factfinder for the Nation: Agricultural Statistics, Bureau
of the Census, 1989). (For more information, see the discussion under
"Farm Residence.")
BEDROOMS
The data on bedrooms were obtained from questionnaire item H9, which
was asked at both occupied and vacant housing units. This item was
asked on a sample basis. The number of bedrooms is the count of rooms
designed to be used as bedrooms; that is, the number of rooms that
would be listed as bedrooms if the house or apartment were on the
market for sale or for rent. Included are all rooms intended to be used
as bedrooms even if they currently are being used for some other
purpose. A housing unit consisting of only one room, such as a one-room
efficiency apartment, is classified, by definition, as having no
bedroom.
Comparability--Data on bedrooms have been collected in every census since
1960. In 1970 and 1980, data for bedrooms were shown only for year-round
units. In past censuses, a room was defined as a bedroom if it was used
mainly for sleeping even if also used for other purposes. Rooms that were
designed to be used as bedrooms but used mainly for other purposes were
not considered to be bedrooms. A distribution of housing units by
number of bedrooms calculated from data collected in a 1986 test showed
virtually no differences in the two versions except in the two bedroom
category, where the previous "use" definition showed a slightly
lower proportion of units.
BOARDED-UP STATUS
Boarded-up status was obtained from questionnaire item C2 and was
determined for all vacant units. Boarded-up units have windows and
doors covered by wood, metal, or masonry to protect the interior and to
prevent entry into the building. A single-unit structure, a unit in a
multi-unit structure, or an entire multi-unit structure may be
boarded-up in this way. For certain census data products, boarded-up
units are shown only for units in the "Other vacant" category. A
unit classified as "Usual home elsewhere" can never be boarded
up. (For more information, see the discussion under "Usual Home
Elsewhere.")
Comparability--This item was first asked in the 1980 census and was shown
only for year-round vacant housing units. In 1990, data are shown for all
vacant housing units.
BUSINESS ON PROPERTY
The data for business on property were obtained from questionnaire
item H5b, which was asked at all occupied and vacant one-family houses
and mobile homes. This question is used to exclude owner-occupied
one-family houses with business or medical offices on the property from
certain statistics on financial characteristics.
A business must be easily recognizable from the outside. It usually
will have a separate outside entrance and have the appearance of a
business, such as a grocery store, restaurant, or barber shop. It may
be either attached to the house or mobile home or be located elsewhere
on the property. Those housing units in which a room is used for
business or professional purposes and have no recognizable alterations
to the outside are not considered as having a business.
Medical offices are considered businesses for tabulation purposes.
Comparability--Data on business on property have been collected since 1940.
CONDOMINIUM FEE
The data on condominium fee were obtained from questionnaire item
H25, which was asked at owner-occupied condominiums. This item was
asked on a sample basis. A condominium fee normally is charged monthly
to the owners of the individual condominium units by the condominium
owners association to cover operating, maintenance, administrative, and
improvement costs of the common property (grounds, halls, lobby,
parking areas, laundry rooms, swimming pool, etc.) The costs for
utilities and/or fuels may be included in the condominium fee if the
units do not have separate meters.
Data on condominium fees may include real estate tax and/or insurance
payments for the common property, but do not include real estate taxes
or fire, hazard, and flood insurance for the individual unit already
reported in questions H21 and H22.
Amounts reported were the regular monthly payment, even if paid by
someone outside the household or remain unpaid. Costs were estimated as
closely as possible when exact costs were not known.
The data from this item were added to payments for mortgages (both
first and junior mortgages and home equity loans); real estate taxes;
fire, hazard, and flood insurance payments; and utilities and fuels to
derive "Selected Monthly Owner Costs" and "Selected Monthly
Owner Costs as a Percentage of Household Income in 1989" for
condominium owners.
Comparability--This is a new item in 1990.
CONDOMINIUM STATUS
The data on condominium housing units were obtained from
questionnaire item H18, which was asked on a sample basis at both
occupied and vacant housing units. Condominium is a type of ownership
that enables a person to own an apartment or house in a development of
similarly owned units and to hold a common or joint ownership in some
or all of the common areas and facilities such as land, roof, hallways,
entrances, elevators, swimming pool, etc. Condominiums may be
single-family houses as well as units in apartment buildings. A
condominium unit need not be occupied by the owner to be counted as
such. A unit classified as "mobile home or trailer" or
"other" (see discussion under "Units in Structure") cannot
be a condominium unit.
Limitation of the Data--Testing done prior to the 1980 and 1990 censuses
indicated that the number of condominiums may be slightly overstated.
Comparability--In 1970, condominiums were grouped together with cooperative
housing units, and the data were reported only for owner-occupied
cooperatives and condominiums. Beginning in 1980, the census identified all
condominium units and the data were shown for renter-occupied and vacant
year-round condominiums as well as owner occupied. In 1970 and 1980, the
question on condominiums was asked on a 100-percent basis. In 1990, it was
asked on a sample basis.
CONTRACT RENT
The data on contract rent (also referred to as "rent asked" for vacant
units) were obtained from questionnaire item H7a, which was asked at all
occupied housing units that were rented for cash rent and all vacant
housing units that were for rent at the time of enumeration.
Housing units that are renter occupied without payment of cash rent are
shown separately as "No cash rent" in census data products. The
unit may be owned by friends or relatives who live elsewhere and who
allow occupancy without charge. Rent-free houses or apartments may be
provided to compensate caretakers, ministers, tenant farmers,
sharecroppers, or others.
Contract rent is the monthly rent agreed to or contracted for,
regardless of any furnishings, utilities, fees, meals, or services that
may be included. For vacant units, it is the monthly rent asked for the
rental unit at the time of enumeration.
If the contract rent includes rent for a business unit or for living
quarters occupied by another household, the respondent was instructed
to report that part of the rent estimated to be for his or her unit
only. Respondents were asked to report rent only for the housing unit
enumerated and to exclude any rent paid for additional units or for
business premises.
If a renter pays rent to the owner of a condominium or cooperative, and
the condominium fee or cooperative carrying charge is also paid by the
renter to the owner, the respondent was instructed to include the fee
or carrying charge.
If a renter receives payments from lodgers or roomers who are listed as
members of the household, the respondent was instructed to report the
rent without deduction for any payments received from the lodgers or
roomers. The respondent was instructed to report the rent agreed to or
contracted for even if paid by someone else such as friends or
relatives living elsewhere, or a church or welfare agency.
In some tabulations, contract rent is presented for all renter-occupied
housing units, as well as specified renter-occupied and vacant-for-rent
units. Specified renter-occupied and specified vacant-for-rent units
exclude one-family houses on 10 or more acres. (For more information on
rent, see the discussion under "Gross Rent.")
Median and Quartile Contract Rent--The median divides the rent distribution
into two equal parts.
Quartiles divide the rent distribution into four equal parts. In
computing median and quartile contract rent, units reported as "No
cash rent" are excluded. Median and quartile rent calculations are
rounded to the nearest whole dollar. (For more information on medians
and quartiles, see the discussion under "Derived Measures.")
Aggregate Contract Rent--To calculate aggregate contract rent, the amount
assigned for the category "Less than $80" is $50. The amount assigned to
the category "$1,000 or more" is $1,250. Mean contract rent is
rounded to the nearest whole dollar. (For more information on
aggregates and means, see the discussion under "Derived Measures.")
Limitation of the Data--In the 1970 and 1980 censuses, contract rent for
vacant units had high allocation rates, about 35 percent.
Comparability--Data on this item have been collected since 1930. For 1990,
quartiles were added because the range of rents and values in the United
States has increased in recent years. Upper and lower quartiles can be used
to note large rent and value differences among various geographic areas.
DURATION OF VACANCY
The data for duration of vacancy (also referred to as "months
vacant") were obtained from questionnaire item D, which was
completed by census enumerators. The statistics on duration of vacancy
refer to the length of time (in months and years) between the date the
last occupants moved from the unit and the time of enumeration. The
data, therefore, do not provide a direct measure of the total length of
time units remain vacant.
For newly constructed units which have never been occupied, the
duration of vacancy is counted from the date construction was
completed. For recently converted or merged units, the time is reported
from the date conversion or merger was completed. Units occupied by an
entire household with a usual home elsewhere are assigned to the
"Less than 1 month" interval.
Comparability--Similar data have been collected since 1960. In 1970 and
1980, these data were shown only for year-round vacant housing units. In
1990, these data are shown for all vacant housing units.
FARM RESIDENCE
The data on farm residence were obtained from questionnaire items
H19a and H19b. An occupied one-family house or mobile home is
classified as a farm residence if: (1) the housing unit is located on a
property of 1 acre or more, and (2) at least $1,000 worth of
agricultural products were sold from the property in 1989. Group
quarters and housing units that are in multi-unit buildings or vacant
are not included as farm residences.
A one-family unit occupied by a tenant household paying cash rent for
land and buildings is enumerated as a farm residence only if sales of
agricultural products from its yard (as opposed to the general property
on which it is located) amounted to at least $1,000 in 1989. A
one-family unit occupied by a tenant household that does not pay cash
rent is enumerated as a farm residence if the remainder of the farm
(including its yard) qualifies as a farm.
Farm residence is provided as an independent data item only for housing
units located in rural areas. It may be derived for housing units in
urban areas from the data items on acreage and sales of agricultural
products on the public-use microdata sample (PUMS) files. (For more
information on PUMS, see Appendix F, Data Products and User
Assistance.)
The farm population consists of persons in households living in farm
residences. Some persons who are counted on a property classified as a
farm (including in some cases farm workers) are excluded from the farm
population. Such persons include those who reside in multi-unit
buildings or group quarters.
Comparability--These are the same criteria that were used to define a farm
residence in 1980. In 1960 and 1970, a farm was defined as a place of 10 or
more acres with at least $50 worth of agricultural sales or a place of less
than 10 acres with at least $250 worth of agricultural sales. Earlier
censuses used other definitions. Note that the definition of a farm
residence differs from the definition of a farm in the Census of
Agriculture (Factfinder for the Nation: Agricultural Statistics, Bureau of
the Census, 1989).
GROSS RENT
Gross rent is the contract rent plus the estimated average monthly
cost of utilities (electricity, gas, and water) and fuels (oil, coal,
kerosene, wood, etc.) if these are paid for by the renter (or paid for
the renter by someone else). Gross rent is intended to eliminate
differentials which result from varying practices with respect to the
inclusion of utilities and fuels as part of the rental payment. The
estimated costs of utilities and fuels are reported on a yearly basis
but are converted to monthly figures for the tabulations. Renter units
occupied without payment of cash rent are shown separately as "No
cash rent" in the tabulations. Gross rent is calculated on a sample
basis.
Comparability--Data on gross rent have been collected since 1940 for
renter-occupied housing units. In 1980, costs for electricity and gas were
collected as average monthly costs. In 1990, all utility and fuel costs
were collected as yearly costs and divided by 12 to provide an average
monthly cost.
GROSS RENT AS A PERCENTAGE OF HOUSEHOLD INCOME IN 1989
Gross rent as a percentage of household income in 1989 is a computed
ratio of monthly gross rent to monthly household income (total
household income in 1989 divided by 12). The ratio was computed
separately for each unit and was rounded to the nearest whole
percentage. Units for which no cash rent is paid and units occupied by
households that reported no income or a net loss in 1989 comprise the
category "Not computed." This item is calculated on a sample
basis.
HOUSE HEATING FUEL
The data on house heating fuel were obtained from questionnaire item
H14, which was asked at occupied housing units. This item was asked on
a sample basis. The data show the type of fuel used most to heat the
house or apartment.
Utility Gas--Includes gas piped through underground pipes from a central
system to serve the neighborhood.
Bottled, Tank, or LP Gas--Includes liquid propane gas stored in bottles or
tanks which are refilled or exchanged when empty.
Fuel Oil, Kerosene, Etc.--Includes fuel oil, kerosene, gasoline, alcohol,
and other combustible liquids.
Wood--Includes purchased wood, wood cut by household members on their
property or elsewhere, driftwood, sawmill or construction scraps, or
the like.
Solar Energy--Includes heat provided by sunlight which is collected,
stored, and actively distributed to most of the rooms.
Other Fuel--Includes all other fuels not specified elsewhere.
No Fuel Used--Includes units that do not use any fuel or that do not have
heating equipment.
Comparability--Data on house heating fuel have been collected since 1940.
The category, "Solar energy" is new for 1990.
INSURANCE FOR FIRE, HAZARD, AND FLOOD
The data on fire, hazard, and flood insurance were obtained from
questionnaire item H22, which was asked at a sample of owner-occupied
one-family houses, condominiums, and mobile homes. The statistics for
this item refer to the annual premium for fire, hazard, and flood
insurance on the property (land and buildings); that is, policies that
protect the property and its contents against loss due to damage by
fire, lightning, winds, hail, flood, explosion, and so on.
Liability policies are included only if they are paid with the fire,
hazard, and flood insurance premiums and the amounts for fire, hazard,
and flood cannot be separated. Premiums are included even if paid by
someone outside the household or remain unpaid. When premiums are paid
on other than a yearly basis, the premiums are converted to a yearly
basis.
The payment for fire, hazard, and flood insurance is added to payments
for real estate taxes, utilities, fuels, and mortgages (both first and
junior mortgages and home equity loans) to derive "Selected Monthly
Owner Costs" and "Selected Monthly Owner Costs as a Percentage of
Household Income in 1989."
A separate question (H23d) determines whether insurance premiums are
included in the mortgage payment to the lender(s). This makes it
possible to avoid counting these premiums twice in the computations.
Comparability--Data on payment for fire and hazard insurance were collected
for the first time in 1980. Flood insurance was not specifically mentioned
in the wording of the question in 1980. The question was asked only at
owner-occupied one-family houses. Excluded were mobile homes,
condominiums, houses with a business or medical office on the property,
houses on 10 or more acres, and housing units in multi-unit buildings.
In 1990, the question was asked of all one-family owner-occupied
houses, including houses on 10 or more acres. It also was asked at
mobile homes, condominiums, and one-family houses with a business or
medical office on the property.
KITCHEN FACILITIES
Data on kitchen facilities were obtained from questionnaire item
H11, which was asked at both occupied and vacant housing units. A unit
has complete kitchen facilities when it has all of the following: (1)
an installed sink with piped water, (2) a range, cook top and
convection or microwave oven, or cookstove, and (3) a refrigerator. All
kitchen facilities must be located in the structure. They need not be
in the same room. Portable cooking equipment is not considered a range
or cookstove. An ice box is not considered to be a refrigerator.
Comparability--Data on complete kitchen facilities were collected for the
first time in 1970. Earlier censuses collected data on individual
components, such as kitchen sink and type of refrigeration equipment. In
1970 and 1980, data for kitchen facilities were shown only for year-round
units. In 1990, data are shown for all housing units.
MEALS INCLUDED IN RENT
The data on meals included in the rent were obtained from
questionnaire item H7b, which was asked of all occupied housing units
that were rented for cash and all vacant housing units that were for
rent at the time of enumeration.
The statistics on meals included in rent are presented for specified
renter-occupied and specified vacant-for-rent units. Specified
renter-occupied and specified vacant-for-rent units exclude one-family
houses on 10 or more acres. (For more information, see the discussion under
"Contract Rent.")
Comparability--This is a new item in 1990. It is intended to measure
"congregate" housing, which generally is considered to be housing
units where the rent includes meals and other services, such as
transportation to shopping and recreation.
MOBILE HOME COSTS
The data on mobile home costs were obtained from questionnaire item
H26, which was asked at owner-occupied mobile homes. This item was
asked on a sample basis.
These data include the total yearly costs for personal property taxes,
land or site rent, registration fees, and license fees on all
owner-occupied mobile homes. The instructions are to not include real
estate taxes already reported in question H21.
Costs are estimated as closely as possible when exact costs are not
known. Amounts are the total for an entire 12-month billing period,
even if they are paid by someone outside the household or remain
unpaid.
The data from this item are added to payments for mortgages, real
estate taxes, fire, hazard, and flood insurance payments, utilities,
and fuels to derive selected monthly owner costs for mobile homes
owners.
Comparability--This item is new for 1990.
MORTGAGE PAYMENT
The data on mortgage payment were obtained from questionnaire item
H23b, which was asked at owner occupied one-family houses,
condominiums, and mobile homes. This item was asked on a sample basis.
Question H23b provides the regular monthly amount required to be paid
the lender for the first mortgage (deed of trust, contract to purchase,
or similar debt) on the property. Amounts are included even if the
payments are delinquent or paid by someone else. The amounts reported
are included in the computation of "Selected Monthly Owner Costs"
and "Selected Monthly Owner Costs as a Percentage of Household
Income in 1989" for units with a mortgage.
The amounts reported include everything paid to the lender including
principal and interest payments, real estate taxes, fire, hazard, and
flood insurance payments, and mortgage insurance premiums. Separate
questions determine whether real estate taxes and fire, hazard, and
flood insurance payments are included in the mortgage payment to the
lender. This makes it possible to avoid counting these components twice
in the computation of "Selected Monthly Owner Costs."
Comparability--Information on mortgage payment was collected for the first
time in 1980. It was collected only at owner-occupied one-family houses.
Excluded were mobile homes, condominiums, houses with a business or
medical office on the property, one-family houses on 10 or more acres,
and housing units in multi-unit buildings. In 1990, the questions on
monthly mortgage payments were asked of all owner-occupied one-family
houses, including one-family houses on 10 or more acres. They were also
asked at mobile homes, condominiums, and one-family houses with a
business or medical office.
The 1980 census obtained total regular monthly mortgage payments,
including payments on second or junior mortgages, from a single
question. Two questions were used in 1990; one for regular monthly
payments on first mortgages, and one for regular monthly payments on
second or junior mortgages or home equity loans. (For more information,
see the discussion under "Second or Junior Mortgage Payment.")
MORTGAGE STATUS
The data on mortgage status were obtained from questionnaire items
H23a and H24a, which were asked at owner-occupied one-family houses,
condominiums, and mobile homes. "Mortgage" refers to all forms of
debt where the property is pledged as security for repayment of the
debt. It includes such debt instruments as deeds of trust, trust deeds,
contracts to purchase, land contracts, junior mortgages and home equity
loans.
A mortgage is considered a first mortgage if it has prior claim over
any other mortgage or if it is the only mortgage on the property. All
other mortgages, (second, third, etc.) are considered junior mortgages.
A home equity loan is generally a junior mortgage. If no first mortgage
is reported, but a junior mortgage or home equity loan is reported,
then the loan is considered a first mortgage.
In most census data products, the tabulations for "Selected Monthly
Owner Costs" and "Selected Monthly Owner Costs as a Percentage of
Household Income in 1989" usually are shown separately for units
"with a mortgage" and for units "not mortgaged." The
category "not mortgaged" is comprised of housing units owned free
and clear of debt.
Comparability--A question on mortgage status was included in the 1940 and
1950 censuses, but not in the 1960 and 1970 censuses. The item was
reinstated in 1980 along with a separate question dealing with the
existence of second or junior mortgages. In 1980, the mortgage status
questions were asked at owner-occupied one-family houses on less than
10 acres. Excluded were mobile homes, condominiums, houses with a
business or medical office, houses on 10 or more acres, and housing
units in multi-unit buildings. In 1990, the questions were asked of all
one-family owner-occupied housing units, including houses on 10 or more
acres. They were also asked at mobile homes, condominiums, and houses
with a business or medical office.
PERSONS IN UNIT
This item is based on the 100-percent count of persons in occupied
housing units. All persons occupying the housing unit are counted,
including the householder, occupants related to the householder, and
lodgers, roomers, boarders, and so forth.
The data on "persons in unit" show the number of housing units
occupied by the specified number of persons. The phrase "persons in
unit" is used for housing tabulations, "persons in households"
for population items. Figures for "persons in unit" match those
for "persons in household" for 100-percent data products. In
sample products, they may differ because of the weighting process.
Median Persons in Unit--In computing median persons in unit, a whole number
is used as the midpoint of an interval; thus, a unit with 4 persons is
treated as an interval ranging from 3.5 to 4.5 persons. Median persons is
rounded to the nearest hundredth. (For more information on medians, see the
discussion under "Derived Measures.")
Persons in Occupied Housing Units--This is the total population minus those
persons living in group quarters. "Persons per occupied housing unit" is
computed by dividing the population living in housing units by the number
of occupied housing units.
PERSONS PER ROOM
"Persons per room" is obtained by dividing the number of
persons in each occupied housing unit by the number of rooms in the
unit. Persons per room is rounded to the nearest hundredth. The figures
shown refer, therefore, to the number of occupied housing units having
the specified ratio of persons per room.
Mean Persons Per Room--This is computed by dividing persons in housing
units by the aggregate number of rooms. This is intended to provide a
measure of utilization. A higher mean may indicate a greater degree of
utilization or crowding; a low mean may indicate under-utilization. (For
more information on means, see the discussion under "Derived Measures.")
PLUMBING FACILITIES
The data on plumbing facilities were obtained from questionnaire
item H10, which was asked at both occupied and vacant housing units.
This item was asked on a sample basis. Complete plumbing facilities
include hot and cold piped water, a flush toilet, and a bathtub or
shower. All three facilities must be located inside the house,
apartment, or mobile home, but not necessarily in the same room.
Housing units are classified as lacking complete plumbing facilities
when any of the three facilities are not present.
Comparability--The 1990 data on complete plumbing facilities are not
strictly comparable with the 1980 data. In 1980, complete plumbing
facilities were defined as hot and cold piped water, a bathtub or shower,
and a flush toilet in the housing unit for the exclusive use of the
residents of that unit. In 1990, the Census Bureau dropped the requirement
of exclusive use from the definition of complete plumbing facilities. Of
the 2.3 million year-round housing units classified in 1980 as lacking
complete plumbing for exclusive use, approximately 25 percent of these
units had complete plumbing but the facilities were also used by
members of another household. From 1940 to 1970, separate and more
detailed questions were asked on piped water, bathing, and toilet
facilities. In 1970 and 1980, the data on plumbing facilities were
shown only for year-round units.
POVERTY STATUS OF HOUSEHOLDS IN 1989
The data on poverty status of households were derived from answers
to the income questions. The income items were asked on a sample basis.
Households are classified below the poverty level when the total 1989
income of the family or of the nonfamily householder is below the
appropriate poverty threshold. The income of persons living in the
household who are unrelated to the householder is not considered when
determining the poverty status of a household, nor does their presence
affect the household size in determining the appropriate poverty
threshold. The poverty thresholds vary depending upon three criteria:
size of family, number of children, and age of the family householder
or unrelated individual for one and two-persons households. (For more
information, see the discussion of "Poverty Status in 1989" and "Income in
1989" under Population Characteristics.)
REAL ESTATE TAXES
The data on real estate taxes were obtained from questionnaire item
H21, which was asked at owner-occupied one-family houses, condominiums,
and mobile homes. The statistics from this question refer to the total
amount of all real estate taxes on the entire property (land and
buildings) payable in 1989 to all taxing jurisdictions, including
special assessments, school taxes, county taxes, and so forth.
Real estate taxes include State, local, and all other real estate taxes
even if delinquent, unpaid, or paid by someone who is not a member of
the household. However, taxes due from prior years are not included. If
taxes are paid on other than a yearly basis, the payments are converted
to a yearly basis.
The payment for real estate taxes is added to payments for fire,
hazard, and flood insurance; utilities and fuels; and mortgages (both
first and junior mortgages and home equity loans) to derive
"Selected Monthly Owner Costs" and "Selected Monthly Owner
Costs as a Percentage of Household Income in 1989." A separate
question (H23c) determines whether real estate taxes are included in
the mortgage payment to the lender(s). This makes it possible to avoid
counting taxes twice in the computations.
Comparability--Data for real estate taxes were collected for the first time
in 1980. The question was asked only at owner-occupied one-family houses.
Excluded were mobile homes or trailers, condominiums, houses with a
business or medical office on the property, houses on 10 or more acres,
and housing units in multi-unit buildings. In 1990, the question was
asked of all one-family owner-occupied houses, including houses on 10
or more acres. It also was asked at mobile homes, condominiums, and
one-family houses with a business or medical office on the property.
ROOMS
The data on rooms were obtained from questionnaire item H3, which
was asked at both occupied and vacant housing units. The statistics on
rooms are in terms of the number of housing units with a specified
number of rooms. The intent of this question is to count the number of
whole rooms used for living purposes.
For each unit, rooms include living rooms, dining rooms, kitchens,
bedrooms, finished recreation rooms, enclosed porches suitable for
year-round use, and lodger's rooms. Excluded are strip or pullman
kitchens, bathrooms, open porches, balconies, halls or foyers,
half-rooms, utility rooms, unfinished attics or basements, or other
unfinished space used for storage. A partially divided room is a
separate room only if there is a partition from floor to ceiling, but
not if the partition consists solely of shelves or cabinets.
Median Rooms--This measure divides the room distribution into two equal
parts, one-half of the cases falling below the median number of rooms and
one-half above the median. In computing median rooms, the whole number
is used as the midpoint of the interval; thus, the category "3
rooms" is treated as an interval ranging from 2.5 to 3.5 rooms.
Median rooms is rounded to the nearest tenth. (For more information on
medians, see the discussion under "Derived Measures.")
Aggregate Rooms--To calculate aggregate rooms, an arbitrary value of "10"
is assigned to rooms for units falling within the terminal category, "9
or more." (For more information on aggregates and means, see the
discussion under "Derived Measures.")
Comparability--Data on rooms have been collected since 1940. In 1970 and
1980, these data were shown only for year-round housing units. In 1990,
these data are shown for all housing units.
SECOND OR JUNIOR MORTGAGE PAYMENT
The data on second or junior mortgage payments were obtained from
questionnaire items H24a and H24b, which were asked at owner-occupied
one-family houses, condominiums, and mobile homes. Question H24a asks
whether a second or junior mortgage or a home equity loan exists on the
property. Question H24b provides the regular monthly amount required to
be paid to the lender on all second or junior mortgages and home equity
loans. Amounts are included even if the payments are delinquent or paid
by someone else. The amounts reported are included in the computation
of "Selected Monthly Owner Costs" and "Selected Monthly Owner
Costs as a Percentage of Household Income in 1989" for units with a
mortgage.
All mortgages other than first mortgages are classified as
"junior" mortgages. A second mortgage is a junior mortgage that
gives the lender a claim against the property that is second to the
claim of the holder of the first mortgage. Any other junior mortgage(s)
would be subordinate to the second mortgage. A home equity loan is a
line of credit available to the borrower that is secured by real
estate. It may be placed on a property that already has a first or
second mortgage, or it may be placed on a property that is owned free
and clear.
If the respondents answered that no first mortgage existed, but a
second mortgage did (as in the above case with a home equity loan), a
computer edit assigned the unit a first mortgage and made the first
mortgage monthly payment the amount reported in the second mortgage.
The second mortgage data were then made "No" in question H24a and
blank in question H24b.
Comparability--The 1980 census obtained total regular monthly mortgage
payments, including payments on second or junior mortgages, from one single
question. Two questions were used in 1990: one for regular monthly
payments on first mortgages, and one for regular monthly payments on
second or junior mortgages and home equity loans.
SELECTED MONTHLY OWNER COSTS
The data on selected monthly owner costs were obtained from
questionnaire items H20 through H26 for a sample of owner-occupied
one-family houses, condominiums, and mobile homes. Selected monthly
owner costs is the sum of payments for mortgages, deeds of trust,
contracts to purchase, or similar debts on the property (including
payments for the first mortgage, second or junior mortgages, and home
equity loans); real estate taxes; fire, hazard, and flood insurance on
the property; utilities (electricity, gas, and water); and fuels (oil,
coal, kerosene, wood, etc.). It also includes, where appropriate, the
monthly condominium fee for condominiums and mobile home costs
(personal property taxes, site rent, registration fees, and license
fees) for mobile homes.
In certain tabulations, selected monthly owner costs are presented
separately for specified owner-occupied housing units (owner-occupied
one-family houses on fewer than 10 acres without a business or medical
office on the property), owner-occupied condominiums, and
owner-occupied mobile homes. Data usually are shown separately for
units "with a mortgage" and for units "not mortgaged."
Median Selected Monthly Owner Costs--This measure is rounded to the nearest
whole dollar.
Comparability--The components of selected monthly owner costs were
collected for the first time in 1980. The 1990 tabulations of selected
monthly owner costs for specified owner-occupied housing units are
virtually identical to 1980, the primary difference was the amounts of the
first and second mortgages were collected in separate questions in 1990,
while the amounts were collected in a single question in 1980. The
component parts of the item were tabulated for mobile homes and
condominiums for the first time in 1990.
In 1980, costs for electricity and gas were collected as average
monthly costs. In 1990, all utility and fuel costs were collected as
yearly costs and divided by 12 to provide an average monthly cost.
SELECTED MONTHLY OWNER COSTS AS A PERCENTAGE OF HOUSEHOLD INCOME IN
1989
The information on selected monthly owner costs as a percentage of
household income in 1989 is the computed ratio of selected monthly
owner costs to monthly household income in 1989. The ratio was computed
separately for each unit and rounded to the nearest whole percentage.
The data are tabulated separately for specified owner-
occupied units, condominiums, and mobile homes.
Separate distributions are often shown for units "with a mortgage" and for
units "not mortgaged." Units occupied by households reporting no income or
a net loss in 1989 are included in the "not computed" category. (For more
information, see the discussion under "Selected Monthly Owner Costs.")
Comparability--The components of selected monthly owner costs were
collected for the first time in 1980. The tabulations of "Selected Monthly
Owner Costs as a Percentage of Household Income in 1989" for specified
owner-occupied housing units are comparable to 1980.
SEWAGE DISPOSAL
The data on sewage disposal were obtained from questionnaire item H16,
which was asked at both occupied and vacant housing units. This item
was asked on a sample basis. Housing units are either connected to a
public sewer, to a septic tank or cesspool, or they dispose of sewage
by other means. A public sewer may be operated by a government body or
by a private organization. A housing unit is considered to be connected
to a septic tank or cesspool when the unit is provided with an
underground pit or tank for sewage disposal. The category, "Other
means" includes housing units which dispose of sewage in some other
way.
Comparability--Data on sewage disposal have been collected since 1940. In
1970 and 1980, data were shown only for year-round housing units. In 1990,
data are shown for all housing units.
SOURCE OF WATER
The data on source of water were obtained from questionnaire item
H15, which was asked at both occupied and vacant housing units. Housing
units may receive their water supply from a number of sources. A common
source supplying water to five or more units is classified as a
"Public system or private company." The water may be supplied by
a city, county, water district, water company, etc., or it may be
obtained from a well which supplies water to five or more housing
units. If the water is supplied from a well serving four or fewer
housing units, the units are classified as having water supplied by
either an "Individual drilled well" or an "Individual dug
well." Drilled wells or small diameter wells are usually less than
1-1/2 feet in diameter. Dug wells are usually larger than 1-1/2 feet
wide and generally hand dug. The category, "Some other source"
includes water obtained from springs, creeks, rivers, lakes, cisterns,
etc.
Comparability--Data on source of water have been collected since 1940. In
1970 and 1980, data were shown only for year-round housing units. In 1990,
data are shown for all housing units.
TELEPHONE IN HOUSING UNIT
The data on telephones were obtained from questionnaire item H12,
which was asked at occupied housing units. This item was asked on a
sample basis. A telephone must be inside the house or apartment for the
unit to be classified as having a telephone. Units where the respondent
uses a telephone located inside the building but not in the
respondent's living quarters are classified as having no telephone.
Comparability--Data on telephones in 1980 are comparable to 1990. The 1960
and 1970 censuses collected data on telephone availability. A unit was
classified as having a telephone available if there was a telephone
number on which occupants of the unit could be reached. The telephone
could have been in another unit, in a common hall, or outside the
building.
TENURE
The data for tenure were obtained from questionnaire item H4, which
was asked at all occupied housing units. All occupied housing units are
classified as either owner occupied or renter occupied.
Owner Occupied--A housing unit is owner occupied if the owner or co-owner
lives in the unit even if it is mortgaged or not fully paid for. The owner
or co-owner must live in the unit and usually is the person listed in
column 1 of the questionnaire. The unit is "Owned by you or someone
in this household with a mortgage or loan" if it is being purchased
with a mortgage or some other debt arrangement such as a deed of trust,
trust deed, contract to purchase, land contract, or purchase agreement.
The unit is also considered owned with a mortgage if it is built on
leased land and there is a mortgage on the unit.
A housing unit is "Owned by you or someone in this household free
and clear (without a mortgage)" if there is no mortgage or other
similar debt on the house, apartment, or mobile home including units
built on leased land if the unit is owned outright without a mortgage.
Although owner-occupied units are divided between mortgaged and owned free
and clear on the questionnaire, census data products containing 100-percent
data show only total owner-occupied counts. More extensive mortgage
information was collected on the long-form questionnaire and are shown
in census products containing sample data. (For more information, see
the discussion under "Mortgage Status.")
Renter Occupied--All occupied housing units which are not owner occupied,
whether they are rented for cash rent or occupied without payment of cash
rent, are classified as renter occupied. "No cash rent" units are
separately identified in the rent tabulations. Such units are generally
provided free by friends or relatives or in exchange for services such
as resident manager, caretaker, minister, or tenant farmer. Housing
units on military bases also are classified in the "No cash rent"
category. "Rented for cash rent" includes units in continuing
care, sometimes called life care arrangements. These arrangements
usually involve a contract between one or more individuals and a health
services provider guaranteeing the individual shelter, usually a house
or apartment, and services, such as meals or transportation to shopping
or recreation.
Comparability--Data on tenure have been collected since 1890. In 1970, the
question on tenure also included a category for condominium and cooperative
ownership. In 1980, condominium units and cooperatives were dropped
from the tenure item, and since 1980, only condominium units are
identified in a separate question.
For 1990, the response categories were expanded to allow the respondent
to report whether the unit was owned with a mortgage or free and clear
(without a mortgage). The distinction between units owned with a
mortgage and units owned free and clear was added in 1990 to improve
the count of owner-occupied units. Research after the 1980 census
indicated some respondents did not consider their units owned if they
had a mortgage.
UNITS IN STRUCTURE
The data on units in structure (also referred to as "type of
structure") were obtained from questionnaire item H2, which was
asked at all housing units. A structure is a separate building that
either has open spaces on all sides or is separated from other
structures by dividing walls that extend from ground to roof. In
determining the number of units in a structure, all housing units, both
occupied and vacant, are counted. Stores and office space are excluded.
The statistics are presented for the number of housing units in
structures of specified type and size, not for the number of
residential buildings.
1-Unit, Detached--This is a 1-unit structure detached from any other house;
that is, with open space on all four sides. Such structures are considered
detached even if they have an adjoining shed or garage. A one-family house
that contains a business is considered detached as long as the building has
open space on all four sides. Mobile homes or trailers to which one or
more permanent rooms have been added or built also are included.
1-Unit, Attached--This is a 1-unit structure that has one or more walls
extending from ground to roof separating it from adjoining structures. In
row houses (sometimes called townhouses), double houses, or houses attached
to nonresidential structures, each house is a separate, attached structure
if the dividing or common wall goes from ground to roof.
2 or More Units--These are units in structures containing 2 or more housing
units, further categorized as units in structures with 2, 3 or 4, 5 to 9,
10 to 19, 20 to 49, and 50 or more units.
Mobile Home or Trailer--Both occupied and vacant mobile homes to which no
permanent rooms have been added are counted in this category. Mobile homes
or trailers used only for business purposes or for extra sleeping space and
mobile homes or trailers for sale on a dealer's lot, at the factory, or in
storage are not counted in the housing inventory.
Other--This category is for any living quarters occupied as a housing unit
that does not fit the previous categories. Examples that fit this
category are houseboats, railroad cars, campers, and vans.
Comparability--Data on units in structure have been collected since 1940
and on mobile homes and trailers since 1950. In 1970 and 1980, these data
were shown only for year-round housing units. In 1990, these data are shown
for all housing units. In 1980, the data were collected on a sample basis.
The category, "Boat, tent, van, etc." was replaced in 1990 by the
category "Other." In some areas, the proportion of units
classified as "Other" is far larger than the number of units that
were classified as "Boat, tent, van, etc." in 1980.
USUAL HOME ELSEWHERE
The data for usual home elsewhere are obtained from questionnaire
item B, which was completed by census employees. A housing unit
temporarily occupied at the time of enumeration entirely by persons
with a usual residence elsewhere is classified as vacant. The occupants
are classified as having a "Usual home elsewhere" and are counted
at the address of their usual place of residence. Typical examples are
people in a vacation home, persons renting living quarters temporarily
for work, and migrant workers.
Limitation of the Data--Evidence from previous censuses suggests that in
some areas enumerators marked units as "vacant--usual home elsewhere" when
they should have marked "vacant--regular."
Comparability--Data for usual home elsewhere was tabulated for the first
time in 1980.
UTILITIES
The data on utility costs were obtained from questionnaire items
H20a through H20d, which were asked of occupied housing units. These
items were asked on a sample basis.
Questions H20a through H20d asked for the yearly cost of utilities
(electricity, gas, water) and other fuels (oil, coal, wood, kerosene,
etc.). For the tabulations, these yearly amounts are divided by 12 to
derive the average monthly cost and are then included in the
computation of "Gross Rent," "Gross Rent as a Percentage of
Household Income in 1989," "Selected Monthly Owner Costs," and
"Selected Monthly Owner Costs as a Percentage of Household Income in
1989."
Costs are recorded if paid by or billed to occupants, a welfare agency,
relatives, or friends. Costs that are paid by landlords, included in
the rent payment, or included in condominium or cooperative fees are
excluded.
Limitation of the Data--Research has shown that respondents tended to
overstate their expenses for electricity and gas when compared to utility
company records. There is some evidence that this overstatement is reduced
when yearly costs are asked rather than monthly costs. Caution should be
exercised in using these data for direct analysis because costs are not
reported for certain kinds of units such as renter-occupied units with all
utilities included in the rent and owner-occupied condominium units with
utilities included in the condominium fee.
Comparability--The data on utility costs have been collected since 1980 for
owner-occupied housing units, and since 1940 for renter-occupied
housing units. In 1980, costs for electricity and gas were collected as
average monthly costs. In 1990, all utility and fuel costs were
collected as yearly costs and divided by 12 to provide an average
monthly cost.
VACANCY STATUS
The data on vacancy status were obtained from questionnaire item C1,
which was completed by census enumerators. Vacancy status and other
characteristics of vacant units were determined by enumerators
obtaining information from landlords, owners, neighbors, rental agents,
and others. Vacant units are subdivided according to their housing
market classification as follows:
For Rent--These are vacant units offered "for rent," and vacant units
offered either "for rent" or "for sale."
For Sale Only--These are vacant units being offered "for sale only,"
including units in cooperatives and condominium projects if the individual
units are offered "for sale only."
Rented or Sold, Not Occupied--If any money rent has been paid or agreed
upon but the new renter has not moved in as of the date of enumeration, or
if the unit has recently been sold but the new owner has not yet moved in,
the vacant unit is classified as "rented or sold, not occupied."
For Seasonal, Recreational, or Occasional Use--These are vacant units used
or intended for use only in certain seasons or for weekend or other
occasional use throughout the year.
Seasonal units include those used for summer or winter sports or
recreation, such as beach cottages and hunting cabins. Seasonal units
also may include quarters for such workers as herders and loggers.
Interval ownership units, sometimes called shared-ownership or
time-sharing condominiums, also are included here.
For Migrant Workers--These include vacant units intended for occupancy by
migratory workers employed in farm work during the crop season. (Work in a
cannery, a freezer plant, or a food-processing plant is not farm work.)
Other Vacant--If a vacant unit does not fall into any of the
classifications specified above, it is classified as "other vacant." For
example, this category includes units held for occupancy by a caretaker or
janitor, and units held for personal reasons of the owner.
Homeowner Vacancy Rate--This is the percentage relationship between the
number of vacant units for sale and the total homeowner inventory. It is
computed by dividing the number of vacant units for sale only by the sum of
the owner-occupied units and the number of vacant units that are for sale
only.
Rental Vacancy Rate--This is the percentage relationship of the number of
vacant units for rent to the total rental inventory. It is computed by
dividing the number of vacant units for rent by the sum of the renter-
occupied units and the number of vacant units for rent.
Comparability--Data on vacancy status have been collected since 1940. For
1990, the category, "seasonal/recreational/occasional use" combined vacant
units classified in 1980 as "seasonal or migratory" and "held
for occasional use." Also, in 1970 and 1980, housing characteristics
generally were presented only for year-round units. In 1990, housing
characteristics are shown for all housing units.
VALUE
The data on value (also referred to as "price asked" for vacant units) were
obtained from questionnaire item H6, which was asked at housing units that
were owned, being bought, or vacant for sale at the time of enumeration.
Value is the respondent's estimate of how much the property (house and lot,
mobile home and lot, or condominium unit) would sell for if it were for
sale. If the house or mobile home was owned or being bought, but the land
on which it sits was not, the respondent was asked to estimate the combined
value of the house or mobile home and the land. For vacant units, value was
the price asked for the property.
Value was tabulated separately for all owner-occupied and
vacant-for-sale housing units, owner-occupied and vacant-for-sale
mobile homes or trailers, and specified owner-occupied and specified
vacant-for-sale housing units. Specified owner-occupied and specified
vacant-for-sale housing units include only one-family houses on fewer
than 10 acres without a business or medical office on the property. The
data for "specified units" exclude mobile homes, houses with a
business or medical office, houses on 10 or more acres, and housing
units in multi-unit buildings.
Median and Quartile Value--The median divides the value distribution into
two equal parts. Quartiles divide the value distribution into four equal
parts. These measures are rounded to the nearest hundred dollars. (For more
information on medians and quartiles, see the discussion under
"Derived Measures.")
Aggregate Value--To calculate aggregate value, the amount assigned for the
category "Less than $10,000" is $9,000. The amount assigned to the
category "$500,000 or more" is $600,000. Mean value is rounded to
the nearest hundred dollars. (For more information on aggregates and
means, see the discussion under "Derived Measures.")
Comparability--In 1980, value was asked only at owner-occupied or vacant-
for-sale one-family houses on fewer than 10 acres with no business or
medical office on the property and at all owner-occupied or vacant-for-sale
condominium housing units. Mobile homes were excluded. Value data were
presented for specified owner-occupied housing units, specified vacant-for-
sale-only housing units, and owner-occupied condominium housing units.
In 1990, the question was asked at all owner-occupied or
vacant-for-sale-only housing units with no exclusions. Data presented
for specified owner-occupied and specified vacant-for-sale-only housing
units will include one-family condominium houses but not condominiums in
multi-unit structures since condominium units are now identified only in
long-form questionnaires.
For 1990, quartiles have been added because the range of values and
rents in the United States has increased in recent years. Upper and
lower quartiles can be used to note large value and rent differences
among various geographic areas.
VEHICLES AVAILABLE
The data on vehicles available were obtained from questionnaire item
H13, which was asked at occupied housing units. This item was asked on
a sample basis. These data show the number of households with a
specified number of passenger cars, vans, and pickup or panel trucks of
one-ton capacity or less kept at home and available for the use of
household members. Vehicles rented or leased for one month or more,
company vehicles, and police and government vehicles are included if
kept at home and used for nonbusiness purposes. Dismantled or immobile
vehicles are excluded. Vehicles kept at home but used only for business
purposes also are excluded.
Vehicles Per Household--This is computed by dividing aggregate vehicles
available by the number of occupied housing units.
Limitation of the Data--The 1980 census evaluations showed that the number
of automobiles was slightly overreported; the number of vans and trucks
slightly underreported. The statistics do not measure the number of
vehicles privately owned or the number of households owning vehicles.
Comparability--Data on automobiles available were collected from 1960 to
1980. In 1980, a separate question also was asked on the number of trucks
and vans. The data on automobiles and trucks and vans were presented
separately and also as a combined vehicles available tabulation. The
1990 data are comparable to the 1980 vehicles available tabulations.
YEAR HOUSEHOLDER MOVED INTO UNIT
The data on year householder moved into unit were obtained from
questionnaire item H8, which was asked at occupied housing units. This
item was asked on a sample basis. These data refer to the year of the
latest move by the householder. If a householder moved back into a
housing unit he or she previously occupied, the year of the latest move
was reported. If the householder moved from one apartment to another
within the same building, the year the householder moved into the
present apartment was reported. The intent is to establish the year the
present occupancy by the householder began. The year that the
householder moved in is not necessarily the same year other members of
the household moved, although in the great majority of cases an entire
household moves at the same time.
Comparability--In 1960 and 1970, this question was asked of every person
and included in population reports. This item in housing tabulations refers
to the year the householder moved in. In 1980 and 1990, the question was
asked only of the householder.
YEAR STRUCTURE BUILT
The data on year structure built were obtained from questionnaire
item H17, which was asked at both occupied and vacant housing units.
This item was asked on a sample basis. Data on year structure built
refer to when the building was first constructed, not when it was
remodeled, added to, or converted. For housing units under construction
that met the housing unit definition--that is, all exterior windows,
doors, and final usable floors were in place--the category "1989 or
March 1990" was used. For a houseboat or a mobile home or trailer,
the manufacturer's model year was assumed to be the year built. The
figures shown in census data products relate to the number of units
built during the specified periods that were still in existence at the
time of enumeration.
Median Year Structure Built--The median divides the distribution into two
equal parts. The median is rounded to the nearest calendar year. Median age
of housing can be obtained by subtracting median year structure built from
1990. For example, if the median year structure built is 1957, the median
age of housing in that area is 33 years (1990 minus 1957).
Limitation of the Data--Data on year structure built are more susceptible
to errors of response and nonreporting than data on many other items
because respondents must rely on their memory or on estimates by persons
who have lived in the neighborhood a long time. Available evidence
indicates there is underreporting in the older-year-structure- built
categories, especially "Built in 1939 or earlier." The introduction of the
"Don't know" category (see the discussion on "Comparability") may have
resulted in relatively higher allocation rates. Data users should refer to
the discussion in Appendix C, Accuracy of the Data, and to the allocation
tables.
Comparability--Data on year structure built were collected for the first
time in the 1940 census. Since then, the response categories have been
modified to accommodate the 10-year period between each census. In 1990,
the category, "Don't Know," was added in an effort to minimize the
response error mentioned in the paragraph above on limitation of the
data.
DERIVED MEASURES
Census data products include various derived measures, such as
medians, means, and percentages, as well as certain rates and ratios.
Derived measures that round to less than 0.1 are not shown but
indicated as zero. In printed reports, zero is indicated by a dash
(-).
Interpolation
Interpolation frequently is used in calculating medians or quartiles
based on interval data and in approximating standard errors from
tables. Linear interpolation is used to estimate values of a function
between two known values. "Pareto interpolation" is an
alternative to linear interpolation. It is used by the Census Bureau in
calculating median income within intervals wider than $2,500. In Pareto
interpolation, the median is derived by interpolating between the
logarithms of the upper and lower income limits of the median category.
Mean
This measure represents an arithmetic average of a set of values. It
is derived by dividing the sum of a group of numerical items (or
aggregate) by the total number of items. Aggregates are used in
computing mean values. For example, mean family income is obtained by
dividing the aggregate of all income reported by persons in families by
the total number of families. (Additional information on means and
aggregates is included in the separate explanations of many population
and housing subjects.)
Median
This measure represents the middle value in a distribution. The
median divides the total frequency into two equal parts: one-half of
the cases fall below the median and one-half of the cases exceed the
median. The median is computed on the basis of the distribution as
tabulated, which is sometimes more detailed than the distribution shown
in specific census publications and other data products.
In reports, if the median falls within the upper interval of the
tabulation distribution, the median is shown as the initial value of
the interval followed by a plus sign (+); if within the lower interval,
the median is shown as the upper value of the category followed by a
minus sign (-). For summary tape files, if the median falls within the
upper or lower interval, it is set to a specified value. (Additional
information on medians is included in the separate explanations of many
population and housing subjects.)
Percentages, Rates, and Ratios
These measures are frequently presented in census products to
compare two numbers or two sets of measurements. These comparisons are
made in two ways: (1) subtraction, which provides an absolute measure
of the difference between two items, and (2) the quotient of two
numbers, which provides a relative measure of difference.
Quartile
This measure divides a distribution into four equal parts. The first
quartile (or lower quartile) is the value that defines the upper limit
of the lowest one-quarter of the cases. The second quartile is the
median. The third quartile (or upper quartile) defines the lower limit
of the upper one-quarter of the cases in the distribution. The
difference between the upper and lower quartiles is called the
interquartile range. This interquartile range is less affected by wide
variations than is the mean. Quartiles are presented for certain
financial characteristics such as housing value and rent.
Page last updated by STATS Indiana May 3, 1999.
