1. Department of Public Health, Simmons University , 300 The Fenway, Boston, MA 02115, USA
2. Department of Public Health, Catholic University of Bukavu, Bugabo , Avenue de la Mission 02, Kadutu Commune, Bukavu, Democratic Republic of Congo
3. Social Science Division, New York University Abu Dhabi , Saadiyat Island, PO Box 129188, Abu Dhabi, United Arab Emirates
4. Development Economics Group, Wageningen University and Research , Hollandseweg 1, 6706 KN, Wageningen, The Netherlands