1. Department of Sociology, University of California at Berkeley, USA
2. Center for Education Policy Research, Harvard University, Cambridge, MA, USA
3. University of California, Irvine, USA
4. Sanford School of Public Policy, Duke University, Durham, NC, USA
5. Department of Economics, Harvard University, National Bureau of Economic Research (NBER), Cambridge, MA, USA
6. Harvard Medical School, Department of Health Care Policy, Boston, MA, USA
7. Congressional Budget Office, NBER, Washington, DC, USA
8. RTI International, Waltham, MA, USA
9. University of Chicago, IL, USA