1. Catalan Institute for Research and Advanced Studies, 08005 Barcelona, Spain;
2. Barcelona Graduate School of Economics, Universitat Pompeu Fabra, 08005 Barcelona, Spain;
3. Barcelona Graduate School of Economics, 08005 Barcelona, Spain;
4. Department of Economics, University of Heidelberg, 69115 Heidelberg, Germany;
5. Department of Economics, University of Essex, Colchester CO4 3SQ, United Kingdom