First Author:   Claudio Lupi ISAE - Institute for Studies and Economic Analyses c.lupi@isae.it   Piazza dell'Indipendenza, 4 Rome, I-00185, Italy   +39 06 4448 2337(Phone) +39 06 4448 2337(Fax) Second Author: Patrizia Ordine University of Calabria, Dept. of Economics and Statistics p.ordine@unical.it   Arcavacata di Rende Cosenza, I-87036, Italy   +39 0984 492458(Phone) +39 0984 492421(Fax)