1. Paris School of Economics, 75014 Paris, France; and Université Paris 1 Panthéon–Sorbonne, Centre d’Economie de la Sorbonne, 75013 Paris, France
2. GREQAM, Aix-Marseille School of Economics, Aix-Marseille University, CNRS, EHESS, Centrale Marseille, 13205 Marseille Cedex 1, France
3. CEE-M (University Montpellier, CNRS, INRA, Montpellier SupAgro), Montpellier, France;
4. Department of Economics, University of Wyoming, Laramie, Wyoming 82071