N'goran Koffi celestin Department of Economics, University Peleforo GON COULIBALY of Korhogo   Cocody , Riviera Faya ,   nkoffiagos2012@gmail.com             JEL Areas: E3 : Prices, Business Fluctuations, and Cycles: General (includes Measurement and Data) C3 : Multiple or Simultaneous Equation Models: General