The present study which started in 1999 is framed in the INCOYAM project. Marketing systems of yam are analyzed in three West- African countries: Cote d'Ivoire, Benin and Nigeria. Surveys have been carried out on urban (wholesales and retailers) and rural (collectors) traders. Cities and...

[eng] International comparisons of real values of final production of agriculture are usually made in Ecu by applying the exchange rate. These comparisons may produce distorted results caused by a difference in price level for the same product in the countries concerned. In all comparisons where...