Beyond the PUMA: Supplemental Geography in ACS Microdata from IPUMS USA

In Public Use Microdata Samples (PUMS) from the American Community Survey (ACS), the only sub-state units identified are Public Use Microdata Areas (PUMAs). The correspondence between PUMAs and other standard geographies (counties, cities, metro areas, etc.) is often inexact. PUMA definitions are also updated after each decennial census, causing inconsistencies in geographic correspondences across time. IPUMS USA leverages the available PUMA information to produce a range of supplementary geographic variables, identifying cities, counties, and metro areas where possible as well as metropolitan status, metropolitan population, and population density. IPUMS USA also produces “consistent PUMAs” that group together PUMAs where boundaries have changed to identify areas with static geographic footprints. This webinar gives an introduction to these PUMA-based variables, describing their key features, the methods we use to produce them, how we measure and report mismatches, and other important considerations for their use. Register to attend.