1. Department of Population Planning and International Health, School of Public Health, University of Michigan, Ann Arbor, Michigan 48109
2. Center to Prevent Childhood Malnutrition, 7200 Wisconsin Avenue, Suite 204, Bethesda, Maryland 20814
3. Institute for International Programs, Johns Hopkins University, Baltimore, Maryland 21205
4. Department of Population Dynamics, Johns Hopkins University, Baltimore, Maryland 21205
5. Department of Biostatistics, Johns Hopkins University, Baltimore, Maryland 21205
6. Population Studies Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104