Uncertainty and Learning in Stochastic Macro Models Piero Ferri - Anna Maria Variato 1 2 April 10, 2008 1 We wish to thank Steven Fazzari and Edward Greenberg (Washington University) for the stimulating collaboration, along with the University of Bergamo for nancial support. 2 University of Bergamo (Italy): pietro-enrico.ferri@unibg.it; anna.variato@unibg.it; +39-035- 2052580; +39-035-2052581.