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Friday, May 20, 2022

Undercount and Overcount

Many posts have discussed the census and population trends.

From the Census Bureau:

The U.S. Census Bureau today released the 2020 Census estimated undercount and overcount rates by state and the District of Columbia from the Post-Enumeration Survey (PES). Also released today are estimated coverage rates by census operation. This includes coverage rates by mode of self-response, and by respondent type in the Nonresponse Followup operation.

“The release of these PES estimates assists us in understanding how well we did this decade, state by state, in our efforts to count everyone living in the United States,” Census Bureau Director Robert L. Santos said. “Transparency is a critical aspect of scientific integrity. That is why we are releasing these results to the public. Our assessments – including the 2020 Census quality indicators, the PES, and the Demographic Analysis released earlier this year – offer valuable insights into the quality of the 2020 Census counts. Although none of the assessments alone can be considered definitive since no “true count” of the population exists, today’s PES results suggest that some states experienced undercounts or overcounts.”

The PES estimates show how well the 2020 Census counted everyone in the nation by creating an independent estimate of the number of people living in the United States on April 1, 2020 (excluding people in group quarters, such as nursing homes or college dorms, and people in Remote Alaska areas), surveying a sample of people in households in the United States and matching those responses to their records in the 2020 Census.

“Achieving an accurate count for all 50 states and DC is always a difficult endeavor, and these results suggest it was difficult again in 2020, particularly given the unprecedented challenges we faced,” Santos added. “It is important to remember that the quality of the 2020 Census total population count is robust and consistent with that of recent censuses. However, we know there is still more work to do in planning future censuses to ensure equitable coverage across the United States and we are working to overcome any and all obstacles to achieve that goal.”

This release includes:Undercount and overcount estimates for states, the District of Columbia (a state equivalent) and regions.
Components of coverage by state and the District of Columbia to estimate the proportions of census records that are correct, wrong, or we don’t have enough information to be sure one way or the other. They include correct enumerations, erroneous enumerations, whole-person imputations, and omissions.
National components of census coverage: Correct or erroneous enumerations and whole-person imputations by census operation and mode, including self-response by mode (internet, telephone, paper) and Nonresponse Followup by type of enumeration.

Key findings: 
  • 37 states (or state equivalent) did not have estimated statistically significant undercounts or overcounts.
  • 14 states (or state equivalent) are estimated to have had an undercount or overcount – a net coverage error statistically different from zero – meaning they were either undercounted or overcounted.Undercount: Arkansas (-5.04%), Florida (-3.48%), Illinois (-1.97%), Mississippi (-4.11%), Tennessee (-4.78%) and Texas (-1.92%).
  • Overcount: Delaware (+5.45%), Hawaii (+6.79%), Massachusetts (+2.24%), Minnesota (+3.84%), New York (+3.44%), Ohio (+1.49%), Rhode Island (+5.05%) and Utah (+2.59%).
Visit the data visualization for a look at coverage for all states and the District of Columbia.