Which farmers benefit the most from Bt corn adoption? Estimating heterogeneity effects in the Philippines
研究使用倾向得分匹配方法，发现菲律宾小规模、非灌溉、偏远地区的农民从Bt玉米采用中获益更多（产量提高、农药和种子用量减少），但利润差异不显著。
Abstract The potential contributions of new biotechnologies to sustainable food and income security have been the subject of widespread discussions around the turn of the 21st century. But distributional issues of which segments of adopters of genetically modified (GM) crops benefit the most have not been given ample attention). Using propensity scores, we apply the (a) stratification‐multilevel method of estimating heterogeneous treatment effects; and the (b) matching‐smoothing method of estimating heterogeneous treatment effects proposed by Xie et al. We find that the incidence of higher yields, lower insecticide use, and reduced seed utilization in the Philippines diminishes progressively as a farmer's propensity to adopt Bt corn increases. Farmers with a low propensity to adopt Bt are those who farm smaller, nonirrigated farms located farther from seed suppliers and farmers without previous training on pest identification. In most cases, while these farmers are typically poorer farmers in smaller parcels, cannot afford irrigation and are situated in remote areas away from easily accessible seed suppliers, there is no evidence, however, that profits differ across farmers with varying propensities to adopt the Bt variety.