1 CU Population Center, Institute of Behavioral Science, University of Colorado Boulder, USA.
2 Department of Sociology, University of Colorado Boulder, USA.
3 School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, South Africa.
4 MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, University of the Witwatersrand, South Africa.
5 Earth Lab, Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder.