Fragmentation, Engel's Law, and Learning

This paper outlines the conditions under which trade is beneficial for a developing country's growth. A developing country suffers from two disadvantages: low income and a comparative disadvantage in the production of modern manufactured goods--goods which allow a high rate of human capital accumulation through learning by doing. Low income together with Engel's law imply that developing countries consume and produce very few modern goods in autarky and hence grow slowly. With international fragmentation of production, a developing country may find comparative advantage in the production of some stages of modern goods despite an absence of comparative advantage in the production of modern goods under "100% local content." More resources can then be allocated to the modern goods sector leading to greater learning externalities and hence growth under free trade than in autarky.