1 DST-NRF Centre of Excellence on Human Development, University of the Witwatersrand, Johannesburg, South Africa. Electronic address: linda.richter@wits.ac.za.
2 DST-NRF Centre of Excellence on Human Development, University of the Witwatersrand, Johannesburg, South Africa.
3 Department of Economics, University of Pennsylvania, Philadelphia, PA, USA.
4 UNICEF, New York Headquarters, New York, NY, USA.
5 Department of Maternal, Newborn, Child, and Adolescent Health, World Health Organization, Geneva, Switzerland.
6 The World Bank, Washington, DC, USA.
7 School of Public Health, University of California, Berkley, CA, USA.
8 Department of Economics, Cornell University, Ithaca, NY, USA.
9 Department of Global Health and Population, Harvard TH Chan School of Public Health, Cambridge, MA, USA.
10 Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland.
11 Early Opportunities, Washington, DC, USA.
12 Social Protection and Health Division, Inter-American Development Bank, Washington, DC, USA.
13 Program in Global Health Economics and Social Change, Harvard Medical School, Cambridge, MA, USA.
14 Alliance for Human Development, Sinai Health System and Obstetrics & Gynaecology, Physiology and Medicine, University of Toronto, Toronto, ON, Canada.
15 National Institute for Early Education Research, Rutgers Graduate School of Education, New Brunswisk, NJ, USA.