Jens Ludwig is the McCormick Foundation Professor of Social Service Administration, Law, and Public Policy at the University of Chicago Harris School of Public Policy and School of Social Service Administration, director of the University of Chicago Crime Lab, and co-director of the University of Chicago Urban Education Lab. He also serves as a non-resident senior fellow in economic studies at the Brookings Institution, research associate of the National Bureau of Economic Research (NBER), and co-director...