Mauro Gallegati Department of Economics - Università Politecnica delle Marche   piazzale Martelli 8 Ancona, I-60100 Italy   gallegati@dea.unian.it   http://www.dea.unian.it/gallegati/           JEL Areas: E3 : Prices, Business Fluctuations, and Cycles: General (includes Measurement and Data) E0 : Macroeconomics and Monetary Economics: General