Commerce Order Bans Differential Privacy for US Census, Reverting to 1970s Methods

A June 4, 2026 Commerce Department directive (DAO 216-26) strips the Census Bureau and Bureau of Economic Analysis of every modern disclosure-avoidance technique, restricting them to 1970s-era methods: coarsening (rounding, grouping, ranges) and, as a last resort, suppression. It explicitly forbids noise infusion, data swapping, and differential privacy — the last being the current state of the art for maximizing data utility at a fixed privacy budget. These techniques underpin dozens of releases over three decades, including the Quarterly Workforce Indicators (input noise since 2002), decennial census swapping (since 1990), OnTheMap commuting data (differential privacy since 2008), and the 2020 Census; differential privacy had been planned for 2030 as well.

The authors, led by Harvard’s Cynthia Dwork and cosigned by numerous CS theory leaders, argue the order is politically rather than scientifically motivated. It bypassed required administrative procedures and tracks the goals of Project 2025 and the Center for Renewing America, founded by OMB Director Russell Vought. The CRA has stated plainly that its aim is to make individual citizenship status ascertainable from census data — which the Census Act (13 U.S.C. §9) makes a crime, since it bars any publication that lets an individual’s furnished data be identified. Confidentiality is also considered essential to census response rates.

The piece demonstrates that coarsening fails on both fronts. In a brewery example, it either renders fine-grained business statistics useless or suppresses them entirely, hurting economic decision-making. Worse, coarsening does not even guarantee confidentiality: with five good-faith coarsened statistics across two towns and four beer-related businesses, an analyst is left with five equations in four unknowns and can recover each company’s exact employee count with high-school algebra. Noise infusion and differential privacy were invented precisely to publish granular data without enabling this kind of reconstruction — which the directive now prohibits.