International and Institutional R&D Spillovers: Attribution of Benefits among Sources for Brazil's New Crop Varieties
用巴西1981-2003年水稻、豆类和大豆品种改良的数据，说明研发收益归因偏差如何影响回报率估算，对农业政策制定者和研究者有参考价值。
Reported rates of return to agricultural R&D are generally high, but they are likely to be biased, particularly because of attribution problems—mismatching research benefits with costs. The importance of attribution biases is illustrated here with new evidence for Brazil. During 1981–2003, varietal improvements in upland rice, edible beans, and soybeans yielded benefits of $14.8 billion in present value (1999 prices) terms. Attributing all of the benefits to Embrapa, a public research corporation accounting for more than half of Brazil's agricultural R&D spending, the benefit‐cost ratio would be 78:1. Under alternative attribution rules, the ratio drops to 16:1.