Evaluating the effects of farm programmes: results from propensity score matching
用倾向得分匹配法评估德国农业环境计划对农户投入和产出的影响，发现参与计划增加了草地面积、降低了牲畜密度和农化品购买量，且受益最大的农户更可能参与。
The paper applies a semi-parametric propensity score matching approach to evaluate the effects of agri-environment (AE) programmes on input use and farm output of individual farms in Germany. The analysis reveals a positive and significant treatment effect of AE programmes on the area under cultivation, in particular grassland, resulting in a decrease of cattle livestock densities. Furthermore, participation significantly reduced the purchase of farm chemicals (fertiliser, pesticide). We also find differences in the treatment effect among individual farms (heterogeneous treatment effects). Farms that can generate the largest benefit from the programme are most likely to participate. Oxford University Press and Foundation for the European Review of Agricultural Economics 2009; all rights reserved. For permissions, please email journals.permissions@oxfordjournals.org, Oxford University Press.