First Author:   Josep M Izquierdo University of Barcelona jizquierdoa@ub.edu   Facultat d''Economia i Empresa, Facultat d''Economia i Empresa, Diagonal 690 Barcelona, E-08034, Espanya   +34 4029090(Phone) +34 4029090(Fax) Second Author: Camilla Di Luca LUISS University cdiluca@luiss.it   Department of Economic and Finance, Viale Romania 32 Rome, 00197       Third Author: Carles Rafels Universitat de Barcelona crafels@ub.edu   Av. Diagonal, 690, Av. Diagonal, 690 Barcelona, E-08034, Espanya