Impact of public research and development and extension on agricultural productivity in China from 1990 to 2013

Agricultural research and extension are two main policy tools that governments can use to generate agricultural growth and transformation. China has made major investments in agricultural research and extension such that it achieved the largest research and extension systems worldwide. This study examined the contribution of public agricultural research and extension to provincial agricultural productivity in China from 1990 to 2013 and estimated the social rate of return on these investments. Employing different lag distribution structures (e.g., trapezoid, gamma, and polynomial) for public agricultural research and extension in the regression analyses, this study found that public agricultural research and development, public extension, and farmers' education have made major contributions to agricultural productivity growth in China. On average, the real rate of return to public investment in agricultural research and development was around 50%, and agricultural extension was 29%. Returns to public research ranged from 24% to 76% and the extension, from 11% to 52% across different provinces.