1. Department of Economics, University of Michigan, 238 Lorch Hall, 611 Tappan St., Ann Arbor, MI 48109-1220.
2. Department of Economics, Washington University in St. Louis, 388 Seigle Hall, St. Louis, MO 63130.
3. Haas School of Business MC1900, University of California, Berkeley 94720.
4. World Bank, 1818 H Street, NW, Washington, DC 20433.
5. Department of Agricultural and Resource Economics, University of California at Berkeley, 207 Giannini Hall #3310, Berkeley, CA 94720-3310.