Christophe Starzec Paris School of Economics, CNRS-CES   106-112 Bd. de l'Hôpital, 106-112 Bd. de l'Hôpital, Paris, Chercheur 75013 France   starzec@univ-paris1.fr             JEL Areas: E3 : Prices, Business Fluctuations, and Cycles: General (includes Measurement and Data) D1 : Household Behavior: General