1 Poverty, Health, and Nutrition Division, International Food Policy Research Institute (IFPRI), Washington, DC 20015; d.headey@cgiar.org cbb2@cornell.edu.
2 Charles H. Dyson School of Applied Economics and Management, Department of Economics, and Atkinson Center for a Sustainable Future, Cornell University, Ithaca, NY 14853 d.headey@cgiar.org cbb2@cornell.edu.