Over the past 50 years and longer, the supply of food commodities has grown faster than the effective market demand, in spite of increasing population and per capita incomes. Consequently, the real (deflated) prices of food commodities have steadily trended down. The past increases in agricultural productivity and production, and the resulting real price trends, are attributable in large part to technological changes enabled by investments in agricultural R&D. Evidence is beginning to emerge of a slowdown in the long-term path of agricultural productivity growth. These productivity patterns mirror a progressive slowing down in the growth rate of total spending on agricultural R&D and a redirection of the funds away from farm productivity that began 20-30 years ago.