Endogenous Formation of Free Trade Agreements: Evidence from the Zollverein's Impact on Market Integration
研究了19世纪最重要的自由贸易协定：关税同盟的成员加入顺序并非随机，而是受联盟规模和进入外国市场的重要性影响，并发现考虑这种内生性后，关税同盟的经济效应比简单估计大数倍。
The Zollverein was arguably the most important free trade agreement of the nineteenth century. Although 1834 is the official date of the Zollverein's establishment, member states joined in a non-random sequence over several decades because the benefits of becoming a member increased, both as the size of the union increased, and as membership in the union became increasingly important for accessing foreign markets. We incorporate the endogenous effects of accession into an estimate of the economic impact of the Zollverein customs union. Our estimated effects are several times larger than simple estimates that do not take these effects into account.