1. Department of Economics, University of California – Berkeley, Berkeley, CA;
2. National Bureau of Economic Research, Cambridge, MA;
3. Department of Economics, University of Southern California, Los Angeles, CA;
4. Department of Economics, Lund University, Lund, Sweden;
5. IZA, Bonn, Germany;
6. Department of Education Reform, University of Arkansas, Fayetteville, AR;
7. Center for Economic and Social Research (CESR), University of Southern California, Los Angeles, CA