1. Department of Sociology, American University, Washington, DC, USA
2. MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), Faculty of Health Sciences, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
3. Population Program, Institute of Behavioral Science, University of Colorado Boulder, Boulder, USA
4. Department of Sociology and Institute of Behavioral Science, University of Colorado Boulder, Boulder, USA
5. Departments of Health Sciences and Women’s & Gender Studies, University of Missouri, Columbia, USA
6. Center for Population and Development Studies, Harvard University, Cambridge, USA