Philip L. Martin is Professor of Agricultural and Resource Economics at the University of California, Davis. Susan F. Martin is Director of the Institute for Study of International Migration and Program on Refugees and Humanitarian Emergencies and Visiting Professor at Georgetown University. Patrick Weil is senior research fellow at the National Center for Scientific Research and serves as the director of the Center for the Study of Immigration, Integration, and Citizenship Policies in the university of Paris-Sorbonne.