This year, the Census Bureau introduced a new privacy mechanism known as ‘differential privacy’, that injects statistical ‘noise’ into the census data, making it harder to identify individuals.

The agency is proposing to limit some of its next round of data from the 2020 census to census tracts, made by combining neighbourhood-level blocks and containing an average of 4,000 people, according to the Associated Press.

If it goes ahead, the move would mean that block-level census data is not available to census users for some data products, which would be a change since the 2010 census. 

Users of census data include researchers, city planning officials and policymakers.

The Census Bureau is consulting on the changes, with data users invited to share their feedback on proposed census products until 22nd October. 

Earlier this year, a federal court in Alabama ruled that the Census Bureau could continue with its differential privacy statistical method, after the state of Alabama raised a challenge that said the approach would lead to inaccurate data.