Yannick Fosso Djoumessi University of Dschang; World Bank Group   djoumessiyannick@gmail.com Dschang, Cameroon   dyannickjugnor@yahoo.fr   https://orcid.org/0000-0002-5245-5125           JEL Areas: C1 : Econometric and Statistical Methods: General Q1 : Agriculture: General