1. Department of Health Policy and Management, University of Pittsburgh, 130 De Soto St., A664 Crabtree Hall, Pittsburgh, PA 15261.
2. Harvard Kennedy School; Department of Health Care Policy, Harvard Medical School; Department of Health Policy and Management, Harvard School of Public Health; and NBER.
3. Department of Health Policy and Management, Harvard School of Public Health, 677 Huntington Ave., Boston, MA 02115.