Researchers ask Census to stop controversial privacy method

This Sunday, April 5, 2020, file photo, shows an envelope containing a 2020 census letter mailed to a U.S. resident in Detroit. The U.S. House has passed a bill that could help protect the 2030 census and other future counts from political interference. (AP Photo/Paul Sancya, File)

Prominent demographers are asking the U.S. Census Bureau to abandon a controversial method for protecting survey and census participants’ confidentiality, saying it is jeopardizing the usability of numbers that are the foundation of the nation’s data infrastructure.

The Census Bureau embraced using differential privacy algorithms for the first time with the release last year of the first round of 2020 census data. Those numbers were used for determining how many congressional seats each state gets, as well as redrawing political districts in a once-a-decade process known as redistricting.

The demographers and other researchers ask in a letter to Census Bureau Director Robert Santos that the agency drop future plans to use the algorithms on two other important data releases — annual population estimates and the American Community Survey figures.