The United States census has an inmate problem

ROBERT HOLBROOK was 17 years old when he went to prison in 1991. For the next 27 years he was incarcerated in several state prisons in Pennsylvania. He was imprisoned at SCI Greene, a supermax prison in the south-western corner of the state, during the 2010 census. Since 1790, the Census Bureau—which began its decennial count on April 1st—has registered incarcerated people as residents of the counties where their prisons are located, not the last address before their arrest. This is important because states then use the census data to draw legislative maps. A prison can bump up a state legislative district’s population, even in places where prisoners cannot vote, which in America means everywhere apart from Maine and Vermont.