This paper examines the theoretical arguments and historical evidence about whether regionalism undermines the multilateral trading system. It first considers how to define multilateralism and then surveys over 60 recent contributions to the literature. It classifies theoretical models by four...

The paper applies a gravity model to 1980-1996 annual non-fuel imports data for 58 countries to quantify the effects of recently created or revamped PTAs on trade. We modify the usual gravity equation to identify separate effects of PTAs on intra-bloc trade, members' total imports and their...

In models with heterogeneous firms trade integration has a positive impact on aggregate productivity through the selection of the best firms as import competition drives the least productive ones out of the market. To quantify the impact of firm selection on productivity, we calibrate and...