This paper presents case-study results and aggregate data to evaluate the impact of research in African agriculture. Of 32 case studies, all but eight report annual returns over 20% and many are far higher, with most gains arising in the late 1980s and 1990s. Spurred by policy reforms and...

This paper addresses the prospects for technical change in the in·igated rice sector of Senegal, and measures ex-ante the economic returns to recent research efforts. In 1994, three new rice varieties were released to farmers in the Senegal River Valley (SRV), the major irrigated rice region in...

This study integrates biophysical simulation data with a farm household model of intertemporal optimization, to investigate changing crop-livestock management practices in the Sudano-Guinean zone of Mali. Over a 15-yr time horizon we find that free grazing on the commons remains more attractive...

Conventional estimates of the economic return to agricultural research use market prices for the values of products and inputs; on this basis, economic rates of return are typically well above the cost of capital, suggesting that more investment in research would be socially desirable. But these...

In this study, we estimate production costs and elasticities of factor substitution for Zimbabwean smallholders, using a dual (cost function) approach with detailed data on prices paid and received by each of 65 farms across six survey sites over two years. We find that 95% of observed farm...