International economies of scale and the gains from trade

In this paper, we present a two-country trade model with external economies of scale that emerge on an international level but are partially localized in each country. First, we show that the larger country exports the good produced in an industry with external economies of scale in the trading equilibrium. Second, we investigate the welfare effects of trade for the following two cases: (I) the case where external economies are completely localized in autarky; (II) the case where external economies are internationally effective in autarky. In case (II), it is shown that trade can be welfare-decreasing for both countries.