commented on an earlier draft. We are particularly grateful to Jeff Swanson for helpful guidance. Colleagues from the MacArthur Foundation Mandated Community Treatment Network, chaired by John Monahan, did much of the research on the relation between mental health and crime. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research. NBER working papers are circulated for discussion and comment purposes. They have not been peerreviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.