MIT economist David Autor made news in January, when he delivered the prestigious Richard T. Ely Lecture at the annual meeting of the American Economic Association and presented an attention-grabbing finding about the U.S. economy. Cities no longer provide an abundance of middle-skill jobs for workers without college degrees, he announced, based on his own careful analysis of decades of federal jobs data, which he scrutinized by occupation, location, and more. MIT News talked to Autor, the Ford Professor of Economics at MIT, about how this sea change is responsible for much of the “hollowing out” of the middle-class work force, and overall inequality, in the U.S.