Who’s Right?: A Novel Use of Survey and Administrative Data to Assess State Population Estimates

Hans Johnson, Public Policy Institute of California (PPIC)
Joseph M. Hayes, Public Policy Institute of California (PPIC)

The Census Bureau and many states report annual estimates of state populations. Some states rely on the Census Bureau’s estimates, while others produce their own estimates. In this study, we exploit both the large sample size of the American Community Survey and a survey item that is new to the survey (as compared to the decennial census) to evaluate the accuracy of state population estimates for highly populated states. Specifically, we compare ACS estimates of the number of women giving birth in the prior year to vital statistics administrative data. Births and the number of women giving birth are thought to be universally recorded in state administrative data, and thus serve as a guide to assess the accuracy of state population estimates among this segment of the population. The results of this research could have important implications for improving estimates of state populations, and will shed new light on the accuracy of those estimates.