1. University of Macerata, Department of Economics and Law, Via Crescimbeni 20, Macerata, I-62100, Italy
2. School of Management, University of Leicester, University Road, Leicester LE1 7RH, UK
3. eHumanities Group, Royal Netherlands Academy of Arts and Sciences, Joan Muyskenweg 25, 1096 CJ Amsterdam, Amsterdam, 1096 CJ, The Netherlands
4. GRAPES – Group of Researchers for Applications of Physics in Economy and Sociology, Rue de la Belle Jardiniere 483, Angleur, B-4031, Belgium