Abhijit Banerjee1, Esther Duflo2, Richard Hornbeck3. 1. MIT Department of Economics, 77 Massachusetts Ave., Building E17, Cambridge, MA 02139 ( banerjee@mit.edu ). 2. MIT Department of Economics, 77 Massachusetts Ave., Building E17, Cambridge, MA 02139 ( eduo@mit.edu ). 3. Department of Economics, Littauer Center 232, Harvard University, Cambridge, MA 02138 ( horn-beck@fas.harvard.edu ).