根据超边际分析法分析既有外生比较优势又有内生比较优势的李嘉图模型，随着交易条件的改进，一般均衡结构必然会从自给自足不连续地跳到具有二元结构的部分分工，然后再跳到完全分工，此时二元结构消失。

This paper applies the infra-marginal analysis, which is a combination of marginal and total cost-benefit analysis, to a model with both constant returns and increasing returns in production. It demonstrates that as transaction conditions are improved, the general equilibrium discontinuously jumps from autarky to partial division of labor with a dual structure, then to the complete division of labor where dual structure disappears. Two types of dual structure may occur in the transitional stage of economic development and globalization. One of them involves the division of labor in the developed economy and autarky in the less developed economy, generating increasing disparity of per capita real income between the two types of economies. The other involves a domestic dual structure in the less developed economy, where the population is divided between commercialized sector which trades with foreign country and self-sufficient sector which is not involved in trade. All gains from trade go to the developed economy. This paper shows that deterioration of a country's terms of trade and an increase of gains that this country receives from trade may concur, provided productivity progress from an expanded network of division of labor outpaces the deterioration of terms of trade. In the model with both endogenous and exogenous comparative advantages, a country may export a good with exogenous comparative disadvantage if endogenous comparative advantage dominates this exogenous comparative disadvantage. Implications of the findings for China's WTO membership and China's trade policy are explored.

提出科教兴国战略的目的是通过加大对科学研究和教育的投入来达到振兴国家的目的。本文运用经济模型从理论和经验两个方面证明了加大对科学研究和教育的投入能够促进经济的不断增长，而经济的不断增长能带动政治和文化诸方面的不断进步和发展，从而达到振兴国家的目的。