First Author:   Marco A. Marini Department of Computer, Control & Management Engineering, Sapienza University of Rome and CREI marini@dis.uniroma1.it   DIAG, Sapienza University of Rome, Via Ariosto, 25 Rome, 00185, Italy   +390677274044(Phone) +390677274044(Fax) www.dis.uniroma1.it/marini/ Second Author: Sergio Currarini University of Leicester, University of Venice and CMCC s.currarini@unive.it   Department of Economics, University of Leicester Leicester, LE1 7RH, United Kingdom       http://www2.le.ac.uk/departments/economics/people/professor-sergio-currarini