First Author:   Neri Salvadori Department of Economics, University of Pisa cicse-lecture@ec.unipi.it   Via Cosimo Ridolfi, 10 Pisa, I - 56124, Italy   +39 050 22 16 215(Phone) +39 050 22 16 215(Fax) http://www.dse.ec.unipi.it/persone/docenti/salvadori_neri.asp Second Author: Luca Gori Department of Economics, University of Pisa luca.gori@ec.unipi.it   Pisa, I - 56124, Italy   +39 050 22 16 212(Phone) +39 050 22 16 384(Fax) http://www.dse.ec.unipi.it/persone/ricercatori/gori_luca.asp