For decades, observers of Africa have referred to the region's economic transformation in the future tense.2 Today, most development scholars agree that Africa has experienced an extraordinary period of economic development in the 21st century, even while the underlying causes are still not fully understood.This chapter on Africa documents the region's unfolding agricultural and broader economic transformations, explores the underlying drivers and implications of these transformations, and considers the new policy priorities dictated by these developments. It starts with an analysis of the shifting role of agriculture in the development of African economies, and the history and status of agricultural transformation and its implications for economic growth, poverty reduction, food systems, and nutrition. The second section reviews changes in agricultural productivity growth over time. The third section discusses patterns of poverty reduction and urbanization and related changes in diets, as well as their effects on agrifood systems and nutrition outcomes. The fourth section summarizes four broad trends that illustrate Africa's agricultural transformation to date and briefly discusses their possible future evolution.
Changing Roles of Agriculture3Agricultural transformation is an important element in overall economic transformation processes (Mellor 1976;Timmer 1988). During the course of agricultural transformation, agrifood systems shift from traditional low-productivity subsistence production systems to commercially oriented, high-productivity systems with significant value addition occurring off the farm (Timmer 1988). Agricultural transformation contributes to overarching Chapter 5 4 Based on World Development Indicators annual growth of agricultural value-added, defined as constant local currency unit value of agriculture, forestry, and fishing outputs minus input costs (WDI code NV.AGR.TOTL.KD.ZG). Africa's impressive agricultural growth rate over the 2000-2018 period is weighted by population and is led by high rates of growth in Nigeria and Ethiopia, but many African countries also achieved annual growth rates well over the world average of 2.75 percent in this period. 5 All dollars are US dollars.