Foued Mattoussi Faculty of Legal, Economic and Management Sciences of Jendouba   Cité Elmanzah Medjez-El-Bab, 9070 Tunisie   foued.mattoussi@gmail.com             JEL Areas: A1 : General Economics: General. E3 : Prices, Business Fluctuations, and Cycles: General (includes Measurement and Data)