This paper describes sub-Saharan Africa’s contemporary small-holder agricultural challenges in relation to the 20th century’s “green revolutions,” especially in Asia. Four key points stand out from the distilling evidence from the agronomics and economics literatures. First, each country’s deployment of its own green revolution package typically amounted to a discernible policy event, driven by active public sector involvement rather than emerging as a simple product of factor scarcities or market forces. Second, green revolutions are not characterized by a breakthrough in any single intervention technology, but instead by a set of key inputs—namely seeds, fertilizer, water and farmer extension—that are successfully deployed as complements in production. Third, the specific biophysical sub-elements of the package differ by crop type, geography and farming system, so the process of technology diffusion is limited by physical factors. Fourth, much of Africa has faced unique challenges to wide-scale deployment of modern input packages, and there is little evidence of policy efforts having been appropriately targeted to overcoming the region’s core constraints.
