An Analysis of the Effect on Welfare and Growth of Domestic Market Structure and Trade Policy

这个为期四年的研究项目是关于一个国家的市场组织、规则和市场法律对国际贸易和资本形成的各种影响。对这些影响进行了理论分析和实证分析。通过研究，以国际学术期刊为主发表了大量论文（英文21篇，日文6篇）。本文的主要研究结果如下：(1)在具有上游可贸易产品市场和下游非可贸易产品市场的国际贸易垂直链模型中，抑制下游市场的竞争可以产生类似于征收关税的效果。此外，该政策的影响实际上相当于关税政策的影响。(2)当网络外部性与新产品的引入有关时，新企业可能以低于边际成本的价格销售产品。这一结果应用于国际贸易，为政策文献中所谓的边际成本倾销提供了第一个严肃的理论解释。(3)国内市场竞争受到国内市场法规的重要影响，而国内市场法规对资本形成有重要影响。从这些研究中得到的信息是，市场的规则和法律对市场的功能有重大影响，无论是国际还是国内。特别是，这些研究揭示了从我所谓的市场质量的角度分析市场机制的重要性，这可能为微观经济学提供一个全新的理论基础。

This four-year research project is on various effects on international trade and capital formation of a country's market organization, rules, and laws on markets. Those effects have been analyzed by both theoretical and empirical methods. Through the research, a large number of papers (21 English and 6 Japanese language papers) has been published mainly in international academic journals.The main findings of the research are as follows : (1) In a vertical-chain model of international trade that is equipped with an upstream market for tradables and a downstream market for non-tradable services, suppression of competition in the downstream market can create an effect similar to the imposition of a tariff. Moreover, the impact of that policy can be practically equivalent to that of a tariff policy. (2) In the presence of network externalities that appear in association with the introduction of a new product, a new firm may sell at a price below its marginal cost. This result, applied to international trade, gives the first serious theoretical explanation to what is called marginal cost dumping in the policy literature. (3) Competition in a domestic market is crucially affected by a country's domestic rules and laws on market, which significantly influence capital formation in that country.A message from these studies is that rules and laws on markets have significant impacts on the function of a market, either international or domestic. In particular, the studies have revealed the importance of an analysis of market mechanism from the viewpoint of what I call market quality, which may provide a totally new theoretical foundation for microeconomics.