COVID-19 is making it harder to check how accurate the 2020 census was

The U.S. Census Bureau is extending a final round of door knocking into early 2022 for a key survey that helps determine the accuracy of last year’s national head count, NPR has learned.

The change is the latest in a series of delays to the follow-up survey that have been raising concerns about whether the bureau can produce important indicators about who was missed and which groups were over- or undercounted in the 2020 census.

In a statement to NPR, the bureau confirms what was expected to be a month-long operation for gathering information on housing units starting in late October, is now set to begin sometime in November and end in February.

“We adjusted the start date and operational length as a result of the impact of the COVID-19 pandemic on the schedule of the preceding census operations,” the bureau said of the change to the Post-Enumeration Survey’s schedule.

About 1,100 of the bureau’s field representatives — who, like all federal government employees, must be fully vaccinated for COVID-19 by Nov. 22 — will try to interview people at some 14,000 housing units around the country while wearing masks and practicing social distancing.

Some census watchers outside the bureau say they’re worried the difficulties of conducting in-person interviews during the coronavirus pandemic could limit the usefulness of the survey’s findings, which the bureau has said it plans to start releasing within the first three months of 2022.