1 DSI-NRF Centre of Excellence in Human Development, University of the Witwatersrand, Wits School of Public Health, Johannesburg 2193, South Africa. Electronic address: linda.richter@wits.ac.za.
2 Data and Analytics Section, Division of Data, Analytics, Planning and Monitoring, New York, NY, USA.
3 Arab Network for Early Childhood Development, Beirut, Lebanon.
4 Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA, USA.
5 DSI-NRF Centre of Excellence in Human Development, University of the Witwatersrand, Wits School of Public Health, Johannesburg 2193, South Africa.