1. Aix-Marseille School of Economics, Aix-Marseille University, 13001 Marseille, France;
2. National Centre for Scientific Research, 75016 Paris, France;
3. School for Advanced Studies in the Social Sciences, 75006 Paris, France;
4. Department of Economics, McGill University, Montreal, Quebec H3A 0G4, Canada;
5. Research School of Economics, Australian National University, Acton ACT 2601, Australia;
6. Cef.up, Economics Department, University of Porto, 4099-002 Porto, Portugal