هزینه های تجاری تصمیمات ثابت صادرات شرکت و اندازه بازار صادرات

This article presents a model of international trade under monopolistic competition. In the increasing returns sector firms face fixed, in addition to variable, trade costs, and both exporters and non-exporters may coexist. Exporters benefit from access to large foreign markets, thus a small country has a higher share of exporting firms than a large one. In contrast to standard models, the increasing returns sector will be more open in a small country than in a large one, and a small country may be a net exporter of such commodities, despite the disadvantage of a smaller home market.

Standard new trade theory predicts that the profitability of increasing returns to scale production depends positively on the size of the domestic market. A country with a large domestic market for a certain good will have a share of the world’s production of that good that is more than proportional to the size of the domestic market. This effect was first identified by Krugman (1980) and is often called the home market effect. It is widely recognized in the new theory of international trade and economic geography (see Helpman and Krugman, 1985; and Fujita et al., 1999 for overviews). It is common for most models belonging to these traditions to assume that firms are symmetric so either all firms or no firms are exporters. A firm’s decision to export is linked to its decision to produce, hence the home market effect applies to export as well as production. Consequently, a country with a large home market also has a larger than proportional share of the world’s export of increasing returns to scale goods. In Helpman and Krugman (1985) the home market effect increases with trade liberalization. As trade costs decline, increasing returns to scale production becomes less profitable in the country with the small home market, and below a certain level of trade costs, it gets deindustrialized.

The aim of this article has been to give a theoretical background for explaining how the size of export markets affects the share of exporting firms in increasing returns to scale sectors. I have argued that, in contrast to what is predicted in the standard new trade theory, the size of the foreign market should matter for profitability of export. Further, I have argued that there are fixed costs of exporting. This is supported by empirical analysis yet poorly analyzed in theoretical models. Such costs may make it profitable for only a share of firms to export, and both each firm’s export and the share of firms that export can vary with trade costs. The model presented in this article has large structural similarities with standard new trade models, yet it yields predictions that differ sharply: small countries are predicted to have a higher share of exporting firms in the increasing returns to scale sector than large ones, hence this sector is more open in small countries. Further, as long as there are non-exporting firms in both countries, small countries are predicted to be net exporters of increasing returns to scale goods, because export of these goods then only depends on the foreign market size. In contrast to the standard theory, small countries can never get deindustrialized thus they have no reason to fear trade liberalization.