1. University of Minnesota, Department of Applied Economics, 1994 Buford Ave., St. Paul, MN 55108 and World Bank.
2. Harvard University, Department of Economics, Littauer Center M20, Cambridge, MA 02138, Brookings Institution, Center for Global Development, and NBER.
3. Rabat American School, BP 120 c/o American Embassy, Agdal, Rabat, Morocco.