In response to a FOIA lawsuit brought by Harvard Law School’s Election Law Clinic on behalf of Columbia political scientist Justin Phillips, the Census Bureau announced today that it will release the data needed to assess the performance of the differential privacy method that was used to protect privacy in the 2020 Census.
The U.S. Census Bureau announced today that it will release files that the Election Law Clinic at Harvard Law School had sought through litigation in order to evaluate possible bias in the 2020 Census.
The Election Law Clinic and Selendy Gay Elsberg PLLC represent Dr. Justin Phillips, a political scientist at Columbia University, in litigation to enforce a Freedom of Information Act (FOIA) request for the files. These data may reveal unintended distortions in 2020 Census data, which are used to distribute political power and resources and to conduct research across disciplines.
Scholars have contended that the privacy protections adopted by the Census Bureau for the 2020 Census may have systematically skewed the data used for redistricting in a way that underrepresents people of color. In order to determine whether that skew exists, and if so, how large that bias is, Dr. Phillips had filed a FOIA request with the Bureau on July 7, 2022.
Dr. Phillips’s FOIA request sought two files (called the “noisy measurements files”) that would enable outside observers to determine whether the published data from the 2020 Census are systematically skewed. The first is a demonstration file based on 2010 Census data. The second is the actual noisy measurement file used to generate the final 2020 Census data.
Dr. Phillips sued the Census Bureau to enforce his FOIA request on October 31, 2022. On December 1, 2022, the Bureau denied Dr. Phillips’ request for the files, contending that the 2010 file had been deleted, and the 2020 file was exempt from release under FOIA.
Reversing course, in January 2023, the Bureau announced it would recreate and publish the 2010 noisy measurement file. The 2010 file is due to be released on April 3. The Bureau further announced today that it will release the 2020 file, with a schedule for release still to be set. View the full statement here.