University of Zurich - Department of Economics, University of Zurich - Department of Economics, Kamuzu University of Health Sciences, Kamuzu University of Health Sciences, Kamuzu University of Health Sciences, affiliation not provided to SSRN, Harvard University - Harvard Medical School, Harvard University - Harvard Medical School, Northwestern University, Princeton University, Johns Hopkins University, University of California, San Diego (UCSD), Princeton University, Princeton University, University of Alberta, ISI Foundation, University of Florence - Department of Economics and Management, University of Zurich, ISI Foundation and University College London - Department of Economics