1. Department of Economics, Management and Statistics University of Milano‐Bicocca Via Bicocca degli Arcimboldi, 8 Milan 20128 Italy
2. Department of Statistics and Quantitative Methods University of Milano‐Bicocca Via Bicocca degli Arcimboldi, 8 Milan 20128 Italy
3. Department of Economics University of Perugia Via A. Pascoli, 20 Perugia 60123 Italy