Andrew Mason1, Ronald Lee2, Jennifer Xue Jiang3. 1. Department of Economics, University of Hawaii at Manoa, and Population and Health Studies, East-West Center, 2424 Maile Way, Saunders 542, Honolulu, HI 96821. 2. Departments of Demography and Economics, University of California at Berkeley, 2232 Piedmont Ave, Berkeley, CA 94720. 3. Department of Economics, University of Cambridge.