1. School of Demography, The Australian National University, Canberra, Australia
2. MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
3. Institute of Behavioral Science, University of Colorado Boulder, Boulder, CO, USA
4. Department of Public Health, University of Missouri-Columbia, Columbia, MO, USA
5. Department of Sociology, American University, Washington, DC, USA
6. INDEPTH Network, Accra, Ghana
7. Department of Sociology, The Ohio State University, Columbus, OH, USA
8. Department of Sociology, School of Public and International Affairs, and Office of Population Research, Princeton University, Princeton, NJ, USA