1 Does complexity explain the structure of trade?1

This paper analyzes whether complexity, measured by the number of skilled tasks that are performed in production, explains countries ' commodity trade structure. We modify Romalis (2004) model to incorporate advantage differences in complexity across commodities together with differences in the number of mistakes made by workers in the production process in developed and developing countries as a source of comparative advantage. Our model predicts that the share of developed countries in world trade increases with products ' complexity. Empirical tests confirm this prediction. Moreover, we find that complexity complements the explanation provided by skill-intensity on countries ' commodity trade structure. Key words: complexity, skill-intensity, factor proportions, trade structure