The impact of agricultural research in Africa: aggregate and case study evidence
通过32个案例和总体数据，发现非洲农业研究带来高回报，多数年收益率超20%，并推动了1985年后谷物单产持续增长，形成迟来的绿色革命。
Abstract 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 changing incentives, these innovations have led to sustained growth in aggregate cereal crop yields since 1985. Africa's belated ‘green revolution’ is based on new varieties (often with early maturation for drought escape), complemented by new management techniques (typically labor‐intensive efforts to conserve soil moisture and build soil fertility).