2020 Census County Assessment Tool

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Accurate decennial census data are critical to making effective decisions at the national, state, and local levels. The Census Bureau’s population counts affect congressional redistricting, social program funding, school planning, and more.

The importance of the decennial census is clear,  but the 2020 Census faced unprecedented challenges with unknown effects on data quality. From the impact of the COVID-19 pandemic and related stay-at-home orders to new household compositions, displacement of college students, and natural disasters, the U.S. Census Bureau kept encountering new challenges. Because of these issues, the U.S. Census Bureau experienced significant disruptions to its planned operations. Separately, they implemented a new privacy framework for protecting publicly released data and provided households the option to respond on the internet. These factors not only delayed the release of 2020 census data products, but have also led some data users and policy makers to question whether the data are fit to use.

To help state and local decision makers and data users explore the 2020 Census data, the Massive Data Institute at Georgetown University’s McCourt School of Public Policy in collaboration with the Urban Institute developed the 2020 Census County Assessment Tool (CCAT). This tool measures whether the 2020 Census diverges significantly from the 2020 population estimates, which are also created by the U.S. Census Bureau. Additionally, our team compiled data from public and administrative sources to provide context for these differences in population counts and population estimates at the county level. Overall, while no single analysis can provide a true look at the complete quality of the 2020 Census, our goal in this project was to provide data users with an easy-to-use tool that will help them to explore unexpected differences between estimates and the actual outcome of the 2020 Census.

We will continue to update the tool as the Census Bureau releases new 2020 data products, publishes the tool’s underlying data, and provides additional resources. We encourage users to email mdiresearch@georgetown.edu to share how this tool assists their data analyses and suggest future features. 

The 2020 Census County Assessment Tool was developed with support from the Tableau Foundation and Alfred P. Sloan Foundation.