Abstract:

Developing countries are always facing a dilemma: to perform their international divisions and trade just in accordance with their initial comparative advantages or their potential comparative advantages.According to the former, developing countries are not bound to obtain trade gains, and according to the latter, those products possessing strong learning effectiveness in the specialized production can gain dynamic trade benefits.Although the model of trade within industry under external effects still depends on elemental endowments, the comparative advantage of a national product is dynamic, since it depends on whether the selected product has a powerful effect of "learning through doing"or not.Under the circumstances of external payment increase and trade within industry, whether the Rybczynski formula and Stolper—Samuelson formula can be proved correct depends on the magnitude of output resilience with the increase of external payment.Meanwhile, gains in trade within industry also depend on the flexible range of external payment increase in both parties' trade industry.

Key words: external effect, payment increase, dynamic comparative advantage