First Author:   Corrado Di Guilmi Department of Economics - Università Politecnica delle Marche diguilmi@dea.unian.it   Ancona, I-60100, Italy   +39712207112(Phone) +39712207112(Fax) Second Author: Mauro Gallegati Department of Economics - Università Politecnica delle Marche gallegati@dea.unian.it   Ancona, I-60100, Italy   +39712207088(Phone) +39712207120(Fax) Third Author: Edoardo Gaffeo Department of Economics - University of Udine Edoardo.Gaffeo@dse.uniud.it   Udine, I-33100, Italy   +39432249235(Phone) +39432249229(Fax)