'Second-generation' MVs and the evolution of the green revolution: the case of Central Luzon, 1966–1990
利用菲律宾中央吕宋地区1966-1990年11个种植季的农户调查数据，估计产量函数并纠正品种选择偏差，发现第二代抗病虫水稻品种对产量增长的贡献显著大于第一代，是绿色革命持续的关键。
By now new modern rice varieties (MVs) with multiple pest and disease resistance have completely replaced early MVs, such as IRS and IR8, except in a few areas of Asia. This study attempts to identify the changing impacts of 'first-generation' and 'second-generation' MVs on productivity in rice farming by estimating the yield function, while correcting selectivity bias arising from the choice of varieties. For this purpose, we used farm-level survey data collected for eleven cropping seasons in Central Luzon in the Philippines from 1966 to 1990. We found that while the yield advantage of first-generation MVs over traditional varieties was limited, the yield-increasing effect of second-generation MVs over first-generation MVs was highly significant. In particular, the adoption of improved MVs significantly contributed to yield growth under the irrigated condition and during the dry season. Thus, we conclude that the Green Revolution would not have been revolutionary without the development and the diffusion of second-generation MVs with multiple pest and disease resistance.