Michel Grabisch Université Paris 1 Panthéon-Sorbonne   106-112 Boulevard de l'Hôpital 106-112 Boulevard de l'Hôpital Paris, 75013 France   michel.grabisch@univ-paris1.fr             JEL Areas: G1 : General Financial Markets: General (includes Measurement and Data) G2 : Financial Institutions and Services: General