1 Harvard TH Chan School of Public Health and Harvard Humanitarian Initiative, Harvard University, Boston, MA 02115, USA. Electronic address: vsharma@hsph.harvard.edu.
2 Paris School of Economics, Paris, France.
3 Harvard Medical School, Harvard University, Boston, MA 02115, USA; Beth Israel Deaconess Medical Center, Boston, MA, USA; Brigham and Women's Hospital, Boston, USA.