Economics versus politics in trade policy

Do economies of scale contribute to our understanding of trade policy or is ideology and inequality sufficient? We develop a unified theoretical framework that encompasses both strategic economic and political variables deemed to be important in explaining trade policy. We predict that an increase in the scale effect leads to restrictive trade policies in labor-abundant countries and liberal trade policies in capital-abundant countries. Using cross-country data on economies of scale, ideology, inequality and various measures of trade barriers we confirm our predictions and establish that a unified framework, which incorporates economies of scale in production, performs better in explaining trade policy than existing political economy models.