The training and visit (T&V) system is designed to serve as the basis of a national extension service providing information to farm households on all activities engaged in by them. l/It was first implemented by the World Bank in Turkey in the late 1960s. Then, starting in the early 1970s, it was introduced in India, Thailand and Indonesia, followed by other Asian countries. Among African countries, the first to witness its introduction was Kenya in 1982, followed by Cote D'Ivoire in 1984 and Burkina Faso in 1986. Now a linchpin of the agricultural services initiative that is central to the World Bank's current strategy for agricultural growth in Sub-Saharan Africa (SSA), T&V extension is being applied widely in some thirty countries in the region.

This, and the related investments being undertaken by national governments and the World Bank, make it important to have measures of the performance of T&V extension in SSA. There are, however, few recent evaluations of the performance of agricultural extension in SSA (see Birkhaeuser and others 1991, for a review of studies of the impact of agricultural extension). Indeed, in general, few evaluations exist of the impact of T&V extension on agricultural production. One such evaluation, also undertaken at the behest of the World Bank, utilized farmlevel data from northern India (Feder and Slade 1986). It showed that there was a high probability of the rate-of-return on added investments in T&V extension (in the areas covered by the evaluation) being more than 15-20 percent. The rate-of-return on the actual past investments in T&V extension in these areas would have been more than 100 percent.