About the Population Estimates
The U.S. Census Bureau produces population estimates annually for the entire nation. These statistics are made publicly available on the Population Estimates section of their website and select geographies (indicated below) are available on STATS Indiana's Population topic page.
- U.S. counties
- Indiana places
- Indiana townships
Annual, as of July 1 of each year
1990 - forward
Estimates are made at the county level based on administrative records for births, deaths and migration (IRS and Medicare enrollment data primarily). The county estimates are then used as control totals for estimates of townships, cities and towns. The administrative records mentioned previously are not available at the sub-county level so population change for individual townships, cities and towns within a county are estimated based on changes in the number of housing units within these jurisdictions.
With each new issue of July 1 estimates, the population estimates program revises estimates for years back to the last census. Previously released estimates are superseded. Revisions to estimates are usually due to revised or updated administrative input data, changes in methodology, or legal boundary changes, especially for sub-county units of government, such as incorporated places. The frequency of estimates and availability of demographic detail vary by geographic level.
Geographic Boundary Updates and the Estimates Base
In many cases a legal entity has had substantial changes to its boundaries since the last census. In these cases, a comparison of the data shows population change due not only to demographic events (births, deaths and migration) but due also to geographic events (annexations, deannexations, etc.).
In contrast, all boundary updates in the post-census population estimates are reflected in the estimates base and not the year in which the change occurred. Therefore the population estimates show population change caused by demographic events only. A boundary change will make the estimates base for an area larger or smaller, but it will not cause a population estimate to show population growth over time. The Population Division produces tables that include both the Census count and the estimates base and indicate the amount of population change due to boundary changes.