Tchieuzing A Romuald Member of the Research Group in Theoretical and Applied Economics (GRETA)   Douala-Cameroon Douala, Littoral Po.Box 4032 Cameroun   tarf2002@yahoo.fr             JEL Areas: E3 : Prices, Business Fluctuations, and Cycles: General (includes Measurement and Data) E2 : Macroeconomics: Consumption, Saving, Production, Employment, and Investment: General (includes Measurement and Data)