Did crop diversity criterion from CAP green payments affect both economic and environmental farm performances? Quasi-experimental evidence from France
利用2013年欧盟共同农业政策改革作为自然实验，研究绿色补贴中的作物多样性标准对法国农场经济绩效、环境绩效和土地利用的影响，发现该标准主要促使已满足要求的农场调整，整体额外变化有限。
This study aims to shed light on the impact of the crop diversity criterion of green payments on farms' economic and environmental performances, alongside land use practices. In order to provide causal evidence, we exploit the natural experiment from the 2013 Common Agricultural Policy reform, which established stronger crop diversity eligibility criteria for farmers with over 10 ha (and 30 ha) of arable land . More precisely, we use a difference-in-discontinuity design on a sample of French farms and compare those respectively above and below the two thresholds. Our findings suggest that farms around 10 ha experienced significant land reallocation and an increase in crop diversity, while farms around 30 ha increase their number of crops. Interestingly, we also found that the main effects were primarily driven by farms that already met the diversification requirements. This suggests that the crop diversity criterion did not result in much additional change.