Professor in Economics and Public Affairs at Princeton University. A member of the School of Social Science, the Institute for Advanced Studies and visiting professor at IDEI (Toulouse) and CERAS (Paris), he writes for the most important specialist journals, such as “American Economic Review”, “American Journal of Political Science”, “Annales d'Economie et de Statistique” and “Econometria”. He has published : Understanding Poverty (with A. Banerje and D. Mookherjee), Oxford University Press (2006).