How Commerce Secretary Ross got the science behind the census so wrong—and why it matters

A decision this week by a federal court to block the U.S. government’s plan to add a citizenship question to the 2020 census is more than a political setback for Secretary of Commerce Wilbur Ross and President Donald Trump. It also represents a strong vote of confidence in the U.S. statistical community and the value of research. On 15 January, U.S. District Court Judge Jesse Furman of the Southern District of New York declared that Ross had been “arbitrary and capricious” in deciding last year to add the citizenship question. He also ruled that the question would most likely result in leaving millions of noncitizens and Hispanic residents out of the decennial head count.The plaintiffs in the case, some 33 state and local officials as well as numerous civil rights organizations, argued successfully that Ross had violated a federal law governing how to make changes in the census. They also convinced the judge that their jurisdictions would likely suffer politically and economically from an undercount.