Agriculture in the twentieth century was characterized first and foremost by technological innovation that began in the industrialized world and spread to the developing countries as the Green Revolution. This revolution in biological, chemical, and mechanical technology made it possible for agricultural production to grow faster than the demand for food despite a rapidly growing world population. The result was a decline in real agricultural commodity prices throughout this era–a trend that is expected by many researchers to continue at least into the early part of the twenty-first century (Antle et al., Johnson 1998, Rosegrant and Ringer). At the same time, virtually all governments intervened in their agricultural sectors through a wide array of policies, resulting in a pattern of net taxation of agriculture in low-income countries and subsidization of agriculture in high-income countries. This set of events, and the agricultural economics literature that was generated to explain them, is what I will refer to here as the economics of agriculture in the twentieth century.
