Ex post analysis of the crop diversification measure of CAP greening in France.

This article evaluates the impact of the crop diversification measure introduced in France under the 2013 Common Agricultural Policy (CAP) greening reform, which requires farms larger than 30 hectares (ha) to grow at least three crops with limits on the land share of the two largest crops. Using a combination of regression discontinuity design (RDD) and differences-in-differences (DD) methods on panel data from a representative sample of French farms between 2010 and 2016, the study finds that farms exceeding 30 ha increased compliance with the measure by about 5 percentage points and added more crops compared to smaller farms. Both farm groups reduced the share of land devoted to their main crop, but larger farms increased land use for their third- and fourth-largest crops, while smaller farms increased land use for their second- and third-largest crops, reflecting differential responses to the policy. The findings provide a local average treatment effect (LATE) valid near the 30-ha threshold and suggest that the measure effectively influenced farm-level crop diversification behavior in France.