1. Department of Economics, Newcastle University Business School , 5 Barrack Road, Newcastle upon Tyne NE1 4SE, UK
2. Department of Economics, Uppsala University , Kyrkogårdsgatan 10, Uppsala 753 13, Sweden
3. Department of Economics, University of Wisconsin—La Crosse , 339F Wimberly Hall, 1701 Badger Street, La Crosse, WI 54601, USA