Enhancements to Census Bureau's Population Estimates Challenge Program: Key Changes and Implications
The Census Bureau's Population Estimates Challenge Program (PECP) has undergone significant changes aimed at addressing complications that arose from the 2020 Census, which was heavily impacted by the COVID-19 pandemic and confidentiality concerns. These changes, particularly the use of a “blended” population base, allow for greater accuracy in annual population estimates, which play a critical role in determining federal funding allocations for states and localities. The blended base combines data from three main sources: 2020 Census counts, demographic analysis estimates, and population estimates from the Vintage 2020 series. This integration helps the Bureau adjust for inconsistencies and delays in 2020 Census data and provides a more resilient foundation for current and future population estimates.
To continuously improve the PECP and Population Estimates Program (PEP), the Census Bureau has established the Base Evaluation and Research Team (BERT), which monitors the methodology used in creating population estimates. BERT's ongoing research includes exploring new data sources, such as administrative data from agencies like the Department of Justice and Homeland Security, to improve the accuracy of estimates, particularly for foreign-born populations. These data sources are intended to help the Bureau respond to fluctuations in migration trends, which have posed challenges to maintaining accurate population counts.
The PECP now also encourages more direct engagement between local governments and members of the Federal-State Cooperative for Population Estimates (FSCPE). FSCPE members, appointed by state governors, work with the Census Bureau on producing population estimates and now review prerelease estimates alongside local governments to provide input. This change arose from public feedback and underscores the Bureau’s effort to make the program more collaborative and transparent.
In response to feedback from state and local governments, the PECP has become more accommodating regarding submission methods. The Bureau now accepts physical copies of challenge documentation, which allows more flexibility in how governments submit challenges. In addition, localities may suggest new data sources to support their population estimate challenges, provided there is sufficient research backing. This change signals the Bureau’s openness to evolve the program based on government needs and new research, although any further expansion will be carefully evaluated to ensure the accuracy and equity of population estimates.
During the 2022 vintage, the Bureau reviewed twelve population challenges submitted by governmental units, which included two county-level and ten subcounty-level challenges. None of the county challenges were accepted, as they lacked complete documentation, and the Bureau provided feedback to help these counties meet the requirements for future submissions. Of the ten subcounty challenges, three were not accepted—two were withdrawn by the submitting localities upon realizing they did not reflect significant changes, and the third failed to meet the Bureau’s criteria. The seven accepted challenges resulted in population adjustments, five of which showed increases, while two reflected decreases. For instance, the population estimate for Berlin, Massachusetts, decreased by nearly 20 percent following a successful challenge. These accepted adjustments demonstrate the potential impact of accurate population estimates, as even minor population shifts can influence the allocation of federal funds and the planning efforts of state and local governments.
The Bureau’s commitment to improving population estimates extends beyond PECP modifications. Additional research is underway to evaluate different methods for county-level estimates. The Bureau currently uses the cohort-component method, which considers changes in births, deaths, and migration. However, it is exploring the housing unit method, typically used for subcounty estimates, which calculates population based on housing stock changes, such as building permits and housing losses. This research will help the Bureau determine whether a different method may be more suitable for annual county-level estimates and ultimately enhance the accuracy of population data.
With funding from the fiscal year 2024 appropriation, the Census Bureau has also begun hiring additional staff to expand its research capabilities. Seventeen new positions were approved to support research and improvements in the population and housing unit estimates. Although the Bureau initially hired temporary employees due to the lengthy process of hiring permanent staff, it plans to transition to permanent hires by spring 2025. This additional staff capacity will accelerate the Bureau’s research projects, ensuring that critical initiatives like the BERT's ongoing projects and PECP improvements are well-supported.
In sum, the recent updates to the Census Bureau's PECP reflect a concerted effort to address challenges and limitations arising from the 2020 Census, enhance data reliability, and increase the program's accessibility for state and local governments. By embracing a blended data approach, promoting cooperative engagement with local governments, and actively exploring new methods and data sources, the Bureau aims to provide more accurate population estimates that will benefit both federal decision-making and local planning. These changes have significant implications for how federal resources are distributed, as well as for the transparency and responsiveness of the Census Bureau’s population estimates processes.
This blog post is intended to provide general information only and is not guaranteed to be accurate or up-to-date. It does not constitute legal advice.