The European single market and intra‐EU trade: an assessment with heterogeneity‐robust difference‐in‐differences methods
使用异质性稳健的双重差分方法评估欧盟单一市场对成员国间贸易的影响，发现欧盟整体上有效促进了贸易，但效果因加入时间而异，且老成员国对新成员国的出口增长更大。
Abstract We use heterogeneity‐robust difference‐in‐differences (DiD) methods to evaluate the impact of membership in the European Union (EU) single market on international trade. On the policy front, we provide evidence that: (i) on average, the EU has been very effective in promoting trade among its member states; (ii) the trade effects of the EU have been long‐lasting, but heterogeneous across EU cohorts; and (iii) while the EU has benefited both ‘old’ and ‘new’ members, the increase in the exports from the ‘old’ members to the ‘new’ joiners has been disproportionately larger. From a methods and practical perspective, the contribution of this paper is to introduce a new, fast and flexible estimation command that combines leading estimation techniques from the gravity literature with recent methods from the heterogeneity‐robust DiD literature.