1. Division of General Internal Medicine and Health Services Research, David Geffen School of Medicine at University of California, Los Angeles, and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California (D.P.L.)
2. Division of General Internal Medicine, University of Pittsburgh School of Medicine, and Center for Health Equity Research and Promotion, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania (U.R.E.)
3. Department of Economics, Columbia University, New York, New York (A.R.O.)
4. Department of Health Care Policy, Harvard Medical School, Boston, Department of Medicine, Massachusetts General Hospital, Boston, and National Bureau of Economic Research, Cambridge, Massachusetts (A.B.J.).