2020 ACS 5-year data + 2010-2020 geographic crosswalks now on IPUMS NHGIS

IPUMS NHGIS has added the 2016-2020 ACS 5-Year Summary File to our site. NHGIS allows users to select any combo of the 1,100+ tables to download in nationwide files for any of 87 summary levels, down to block groups.

To support comparisons between the new tables and ACS data from earlier years, we've also extended our collection of geographic crosswalks to include crosswalks from 2010 block groups to 2020 block groups, census tracts, and counties, and from 2020 block groups to 2010 block groups, census tracts, and counties.

Although these crosswalks are only "from block groups," they're designed to facilitate analysis at any of the target levels: block groups, census tracts, or counties. For example, to generate data for analysis of 2020 tracts, one could allocate 2006-2010 ACS data for block groups to 2020 tracts using the corresponding crosswalk. Then the output will be directly comparable with tract data in 2016-2020 ACS tables. And by starting from block groups (the lowest available level of ACS summary data), the output will also be more accurate.

The Census Bureau made very few changes to its definitions of census tracts and block groups between 2010 and 2019, and there were only a few county boundary changes, so these 2010-2020 crosswalks generally support bridging between the new 2020 ACS data and any ACS 5-year data release between 2010 and 2019. We provide more details on the few exceptions here.