Today, Common Cause and the Prison Policy Initiative urged the U.S. Census Bureau to change how it counts prison populations each decade. The Bureau’s use of differential privacy, the intentional infusion of inaccurate information into population data, creates unnecessary miscounts in data used by state and local officials for redistricting. In a letter to Director Robert L. Santos and other senior officials, the groups emphasized that the populations of correctional facilities are already publicly available and that differential privacy is unnecessary and produces needless inaccuracies.

The Prison Policy Initiative and Common Cause praised the Census Bureau’s commitment to ensuring the privacy of all U.S. residents by enacting privacy methods that keeps the data of all residents safe. But the groups shared examples illustrating how the Bureau’s implementation of differential privacy resulted in undercounts of incarcerated individuals. In correctional facilities in California and Rhode Island, some inmates were counted outside those facilities.

States like Rhode Island, California, and over a dozen others send their correctional population data to the Census Bureau, which ultimately makes the data inaccurate and then sends it back to the states. The states then have to correct the data before it is usable for redistricting purposes.

“The inaccurate Census Bureau counts of correctional facility populations make it harder for those states looking to do the right thing by counting incarcerated individuals in the communities where they lived before they were imprisoned,” said Keshia Morris Desir, Common Cause Justice & Democracy Manager. “It would be a simple fix for the Bureau to make without violating anyone’s privacy. In the interest of a more accurate Census count and more equitable redistricting maps, we strongly urge the Bureau to make these commonsense changes to its process.”

“For decades, the Census Bureau — despite mountains of evidence — has stubbornly refused to fix its flawed way of counting incarcerated people,” said Aleks Kajstura, the Prison Policy Initiative Legal Director. “This new approach of adding ‘noise’ to official census population numbers threatens to make it even harder for hundreds of local governments and nearly two dozen states that are adjusting their redistricting data to avoid prison gerrymandering. At the bare minimum, the Bureau should rethink their one-size-fits all approach to protect the work of state and local governments, but it would be even better if it actually listened to them and counted incarcerated people at home.”

In addition to calling for new policies to end the avoidable inaccuracies in the current process, the letter ultimately urges the Bureau to make the shift in the 2030 Census to begin counting incarcerated people in the communities where they resided before they were imprisoned.

To read the full letter, click here.