External trade diversion, exclusion incentives and the nature of preferential trade agreements

In a game of endogenous trade agreements between three countries, we show that while the pursuit of customs unions (CUs) prevents global free trade from emerging as a coalition-proof Nash equilibrium, the pursuit of free trade agreements (FTAs) does not. This result reflects the relatively flexible nature of FTAs: whereas each FTA member can independently undertake further trade liberalization with respect to the non-member, CU members must do so as a group due to their common external tariff. By diverting members' exports away from the non-member, both types of trade agreements induce the non-member to voluntarily lower its import tariffs.