Ensuring Fair Representation for Cities & States through Accurate Census Data
August 2024
Accurate U.S. census counts are crucial for fair political representation and the equitable distribution of federal resources.
They determine congressional apportionment and influence the allocation of federal funding for health care, education, infrastructure, and other essential services. Moreover, census data inform critical state and municipal policymaking and provide invaluable information for businesses, researchers, and community planners to make informed decisions.
To ensure the accuracy of its data products, the Census Bureau provides formal mechanisms for states and cities to correct decennial census counts and challenge annual population estimates.
Beginning in 2023, NORC collaborated with the City of Chicago and the State of Illinois to pursue three challenges to Census Bureau data: a Post-Census Group Quarters Review (PCGQR) for both the city and the state to correct for inaccuracies in the 2020 decennial census, and a Population Estimates Challenge for the city to correct for inaccuracies in the Vintage 2022 Chicago population estimate.
These projects are important to me for a number of reasons. First, as a NORC researcher, much of my team’s work relies on the Census Bureau’s data. Any steps that we take to help ensure the accuracy of Census counts will make our own work more accurate. Second, I live in Chicago, so I have a stake in ensuring that the state and city have the best data possible to make informed decisions about programs and policies and receive their fair share of revenue from federal funding allocations. And lastly, I’m enthusiastic about the prospects of expanding this work to other places—particularly when it comes to helping counties or states use their administrative data to produce useful tools and demographic analyses, like population estimates.
“I live in Chicago, so I have a stake in ensuring that the state and city have the best data possible to make informed decisions about programs and policies and receive their fair share of revenue from federal funding allocations.”
Methodology
To review group quarters for the PCGQRs, our team acquired, cleaned, harmonized, and geocoded information about facilities in Chicago and Illinois that met the Census Bureau’s definition of group quarters, such as nursing homes, dorms, prisons, homeless shelters, and residential treatment centers. We then created a list of group quarters and identified gaps between it and the 2020 decennial census records. Then, through direct data collection, our vetting team verified all facilities that had potentially been undercounted.
For the City of Chicago Population Estimates Challenge, we identified the data inputs used in the Census Bureau’s estimate for the 2022 Chicago population and compared them with city administrative records. This involved obtaining, cleaning, and coding a large set of building permit and certificate of occupancy data, and estimating the components of housing unit change; that is, housing unit gain from permitted construction and non-residential to residential housing conversions, and housing unit loss from permitted demolitions and residential to non-residential housing conversions.
Results
- The City of Chicago PCGQR challenge was officially approved by the Census Bureau in June 2023.
- The State of Illinois PCGQR challenge identified 733 group quarters facilities that may have been missed during the 2020 decennial census, representing over 46,000 Illinois residents.
- The Vintage 2022 Population Estimates Challenge resulted in an upward revision of the City of Chicago’s 2022 population estimate by 7,639, and an upward revision of the 2021 population estimate by 5,273. The Census Bureau officially accepted the city’s challenge in February 2024.
Implications
Updated group-quarters population counts for the City of Chicago and the State of Illinois will be incorporated into future annual population estimates released by the Census Bureau through the end of the decade. These population estimates are used to determine the annual distribution of over $675 billion in state and federal programs. Successful challenges to the 2020 Census will bring in more federal funding to Chicago and Illinois.
The annual population estimates are also used as control totals for the American Community Survey (ACS) and Current Population Survey (CPS). Ensuring the accuracy of the annual population estimates improves the accuracy of other Census Bureau data products, on which state, county, and city governments rely for policy development and decision-making.
Illinois Governor JB Pritzker acknowledged the importance of this work in a statement, saying, “This correction will bring in millions in additional federal funding for crucial programs and help to ensure future counts reflect the true number of Illinois residents. I’m grateful to NORC at the University of Chicago for their work on this appeal and all who helped make this decision possible.”
Next Steps
NORC’s demographic, statistical, and data science experts are providing ongoing technical consultation to the City of Chicago as it prepares for a challenge to its Vintage 2023 population estimate. This work entails continued analysis of city building permit data and outreach to group quarters facilities for updated population counts.
I’m particularly interested in exploring future population estimate work at the state level. The abundance of state administrative records is such that individual states, like Illinois, could conceivably produce accurate independent estimates of population and population change for their counties on an annual basis. This would have many benefits, including increased control over methodology and creation of other, useful data products for application across state agencies.
Suggested Citation
Fiorio, L., (2024, August 28). Ensuring Fair Representation for Cities and States through Accurate Census Data. [Web blog post]. NORC at the University of Chicago. Retrieved from https://www.norc.org.
