Industry Characteristics and Scale Economies as Sources of Intra‐industry Trade

1982 US intra‐industry trade (IIT) for 308 four‐digit manufacturing products is related to industry characteristics in a cross‐section regression study of the sources of two‐way trade. Results indicate the empirical relevance of models which present IIT as the result of international external economies in the production of differentiated producers goods. IIT as a means of satisfying consumers′ tastes for variety does not seem to be important, but oligopoly models of two‐way trade in consumer goods are supported owing to the association with concentration ratios. In contrast to recent studies which concluded that scale economies inhibit IIT in manufactured products, an examination of four different proxies for internal economies reveals that neither IIT nor inter‐industry trade based on comparative advantage is influenced significantly by scale effects, whether measured by size of establishment or by the productivity advantages of large plants.