These estimates, together with commodity price data, elasticities of supply and demand and estimates of research costs were combined in an economic surplus model with the number of adopted hectares of forage legumes. Nearly 28,000 adopters were identified, growing forage legumes on some 19,000 ha in 15 countries of the region. The analyses were repeated using two scenarios of projected adoption trends to the year 2014, resulting in at least a quadrupling of the estimated total benefits realised to date. There are serious constraints to the adoption of forage legumes in many places but legumes occupy particular niches in the farming systems of West Africa. The impact of fodder banks has already paid for the research that went into their development at least three times over.
Results are probably conservative, given the modest production impacts used.
The adoption data are strong, but these are balanced by absence of some cost and price information and weak elasticity data. Publications Elbasha E.H., Thornton P.K. and Tarawali G. 1998. An Ex- Post Economic Impact Assessment of Planted Forages in West Africa.