US State Population Estimates and Census 2010 Counts: Did They Match?

How well did the US Census Bureau's population estimates for the first decade of the 21st century match the actual counts from the 2010 Census? The short answer: Pretty well for the nation, and for all but a handful of states.

The accuracy of these population estimates is important because the numbers, which are released each year in between the once-a-decade census counts, are the basis for distributing billions of dollars in federal funds and are the denominators for rates used in some federal surveys. Unlike the census, which counts people directly, the estimates are assembled using government data, including birth and death certificates, immigration estimates and tax-return statistics on people who changed residences.