Over the past fifty years, barriers to international trade have decreased substantially. While the decline in protectionism since World War II has stemmed partly from unilateral changes in trade policy by countries, it also has been a result of agreements among countries to liberalize their...

Societal theories of trade policy stress the importance of domestic interest groups, whereas statist theories focus on the effects of domestic institutions. Debates over the relative merits of these approaches have been fierce, but little systematic empirical research has been brought to bear on...