1. Sloan School of Management, Massachusetts Institute of Technology, Cambridge, MA, USA.
2. Abdul Latif Jameel Poverty Action Lab (J-PAL), Massachusetts Institute of Technology, Cambridge, MA, USA.
3. Kenya Lead Academic, International Growth Center, London, UK.
4. National Bureau of Economic Research, Cambridge, MA, USA.
5. Innovations for Poverty Action, New Haven, CT, USA.
6. Department of Economics, Georgetown University, Washington, DC, USA.