1Department of Economics, University of Catania, Corso Italia 55, 95131 Catania, Italy, CSEF and CEPR (email: )
2Department of Economics, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom, Department of Economics, Lund University (email: )
3Hertie School, Friedrichstraße 180, 10117 Berlin, Germany (email: )