RESUMEN
Over the last twenty years, the number of bilateral and regional preferential trade agreements has increased very rapidly, a phenomenon that has become known as the “new regionalism”. We present an argument to explain this development that starts with exporters that are excluded from a preferential trade agreement. When facing trade diversion, these exporters are likely to mobilize and push their government into signing an agreement with the country in which their exports are threatened. We test our argument against alternative explanations, which emphasize factors such as emulation, geopolitical rivalry, the spread of democracy, and deadlock in multilateral trade negotiations, in a quantitative analysis of the proliferation of preferential trade agreements among 168 countries between 1990 and 2007. By showing that the objective of protecting exporters is indeed a major driving force of the new regionalism, the paper contributes to the literatures on regionalism and policy diffusion.