Ahmed Ben haj hammouda Faculty of Economic Sciences of Sousse University of Souss   Faculty of Economic Sciences of Sousse Erriadh City Sousse, Sousse 4023 Tunisie   ahmedbenhajhamouda@gmail.com             JEL Areas: E5 : Monetary Policy, Central Banking, and the Supply of Money and Credit: General E4 : Money and Interest Rates: General