Census Bureau dodges challenge to controversial privacy tool

The U.S. Census Bureau on Tuesday dodged a challenge for now to its use of a controversial statistical method aimed at keeping people’s data private in the numbers used for redrawing congressional and legislative districts after federal judges refused to stop the technique’s implementation.

A panel of three federal judges in Alabama rejected the state of Alabama’s request for a preliminary injunction to halt the Census Bureau from using the method called differential privacy. The decision in federal court in Opelika, Alabama, allows the Census Bureau, for now, to proceed toward its goal of releasing the redistricting data in mid-August.

The federal judges dismissed counts brought by Alabama that said differential privacy would produce inaccurate data and was unconstitutional. They also dismissed a count by Alabama challenging the Census Bureau’s timetable for releasing the data, but they allowed that count to proceed for three Alabama politicians who joined the state in the lawsuit. The state of Alabama and the politicians also claimed in the lawsuit that the Census Bureau violated proper decision-making rules when coming up with differential privacy, and the judges allowed those counts to move ahead.

Any appeal could go straight to the Supreme Court. Jason Torchinsky, one of the attorneys for Alabama, said he couldn’t immediately comment on the decision. The Census Bureau, and the Commerce Department, which oversees the statistical agency, didn’t respond to a request for comment.

The privacy method known as “differential privacy” adds intentional errors to the data to obscure the identity of any given participant in the 2020 census while still providing statistically valid information. The Census Bureau says more privacy protections are needed than in past decades as technological innovations magnify the threat of people being identified through their census answers, which are confidential by law.

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