英文文献：Are Agricultural R&D Returns Declining and Development Dependent?
英文文献作者：Rao, Xudong,Hurley, Terrance M.,Pardey, Philip G.
英文文献摘要：
There is widespread professional consensus that agricultural research and development (R&D) receives high economic returns, though there is also concern that these returns have been declining over the past few decades and unevenly distributed among different regions in the world. This study attempts to reveal both the time trend (i.e., increasing or decreasing) and regional developmental differences in the reported returns to agricultural R&D. Using a newly updated and expanded global database of estimated returns to agricultural R&D and a robust statistical methodology, our findings suggest that after accounting for methodological changes and other study factors that have varied over time, the contemporary returns to agricultural R&D investments are as high as ever. Furthermore, this study provides evidence that regional developmental differences are attributable to more than differences in the focus of research, researcher or research methodology.