1. Department of Economics, Aarhus University, Fuglesangs Allé 4, DK-8210 Aarhus, Denmark and Research Institute of Industrial Economics (Ifn), Stockholm, Sweden
2. Chair for Public Finance and Economic Policy, Faculty of Management and Economics, Ruhr-University of Bochum, Universitätsstr. 150, Bochum, Germany
3. Departamento de Economía, Edificio Amigos, Universidad de Navarra, Pamplona, Spain