Review reveals census miscounts

Population tally undercounted in six states and overcounted in eight others.

WASHINGTON — The 2020 census undercounted the population of six states and overcounted residents in eight others, the Census Bureau said Thursday, a finding that highlighted the difficulties of conducting the most star-crossed population count in living memory.

The conclusions come from a survey of 161,000 housing units conducted after the census was completed, a standard procedure following each once-a-decade headcount of the U.S. population. The results showed that six states — Arkansas, Florida, Illinois, Mississippi, Tennessee and Texas — most likely have a larger population than was officially counted.

Eight states probably have fewer residents than were recorded, the survey found: Delaware, Hawaii, Massachusetts, Minnesota, New York, Ohio, Rhode Island and Utah. The count in the remaining 36 states and the District of Columbia was basically accurate, the bureau said.

The results were markedly worse than in the 2010 census, in which none of the states had a statistically significant overcount or undercount, the agency found. But they were not unlike the conclusions from the 2000 census post-mortem, which found overcounts in 22 states and an undercount in the District of Columbia.

John H. Thompson, director of the Census Bureau from 2013 to 2017, said he was not surprised by the variations given the problems that dogged the 2020 census. “All censuses have overcounts and undercounts,” he said. “That does not preclude using the results.”

Still, for the states that missed the mark, the numbers were striking. The bureau said the greatest undercount was in Arkansas, where the census likely missed 5.04 percent of the population — some 160,000 people, or the equivalent of nearly 80 percent of the state’s largest city, Little Rock. However, that was just the midrange of a much wider band of estimates. The undercount could have been as small as about 43,000 people, the agency said, or as large as 286,000.

Similarly, the bureau pegged the undercount in fast-growing Texas at 570,000 people, but said it could range roughly between 167,000 and 985,000. And in New York, the bureau estimated that it counted 695,000 more people than actually lived there, but said the estimate could be as low as 382,000 or as high as 1 million.

The Census Bureau said in March that the same survey had found undercounts of Black and Hispanic people in the national population totals, as well as overcounts of white people and people of Asian descent. Overcounts of white people and undercounts of other racial and ethnic groups have been a persistent problem in past censuses.

The survey was not broad enough to offer reliable estimates of those racial and ethnic discrepancies on a state-bystate basis, the bureau said.

The post-mortem will not change the official state-by-state results of the census, which said 331,449,281 people were living in the United States in 2020. Nor will it alter the allotment of seats in the House of Representatives or the map boundaries in state and local political districts, which are redrawn every 10 years using census results.

The Supreme Court has barred the use of surveys in apportioning seats in the House, and in any case, the large margin of error in the post-2020 census survey makes its conclusions more like educated guesses than solid findings.

“There definitely would have been changes in reapportionment,” said Andrew Beveridge, a demographics expert and a professor emeritus of sociology at Queens College. “But just how isn’t clear.”