1. School of Business, University of Leicester, Brookfield, Leicester LE2 1RQ, UK
2. Group for Research and Applications of Physics in Economy and Sociology (GRAPES), Rue de la Belle Jardinière 483, Angleur, B-4031 Liège, Belgium
3. Department of Statistics and Econometrics, The Bucharest University of Economic Studies, Caeia Dorobantilor 15-17, 010552 Bucharest, Romania
4. Universitatea Babe-Blolyai, Str. Mihail Kogălniceanu nr. 1, 400084 Cluj-Napoca, Romania
5. Department of Statistical Sciences, Sapienza University of Rome, Piazzale Aldo Moro 5, I-00185 Rome, Italy
6. Department of Social and Economic Sciences, Sapienza University of Rome, Piazzale Aldo Moro 5, I-00185 Rome, Italy
7. Groupe de Recherche Angevin en Économie et Management (GRANEM), University of Angers, SFR Confluences, F-49000 Angers, France