1. Department of Mathematics, Informatics and Economics, University of Basilicata, I-85100 Potenza, Italy
2. Department of Sociology, University of the Aegean, Mitilini Hill, GR-08110 Lesvos, Greece
3. Global Change Research Institute CAS, Lipova 9, CZ-370 05 Ceske Budejovice, Czech Republic
4. Department of Methods and Models for Economics, Territory and Finance, Faculty of Economics, Sapienza University of Rome, I-00185 Rome, Italy