Chuaibou Mounmom ESSEC University of Douala   S.C BP 1931 Douala, Littoral 237 Cameroun   mchuaibou@gmail.com             JEL Areas: N1 : Economic History: Macroeconomics and Monetary Economics; Growth and Fluctuations: General, International, or Comparative C4 : Econometric and Statistical Methods: Special Topics