A Study on Enforcement in the Institution of Intellectual Property Rights

首先，我们通过对拥有两项互补技术专利的双寡头企业之间的许可，考察了知识产权的实施对均衡结果和福利的影响。其次，构建了一个由两个出口国(一个发达国家和一个发展中国家)的企业和一个进口国组成的三国国际贸易博弈模型。通过对发达国家企业技术知识产权许可、知识产权穷竭和知识产权侵权诉讼的处理，我们得到了一个子博弈的完美纳什均衡。再次，我们考察了当跨国药品价格差异不仅是由于需求弹性因素，而且是由于政府…的影响时，平行进口对药品创新和经济福利的影响更多以药品价格管制为主的因素。通过明确考虑基于政府药品价格管制的因素，我们发现在一定条件下，在国外政府的议价能力和国外市场需求的价格弹性条件下，平行进口可以促进药品创新。我们还表明，平行进口导致的研发增加甚至可能增加一个需求弹性高的国家的消费者剩余，如果不允许平行进口，这个国家可能面临相对较低的药品价格。第四，我们通过拥有两项互补技术专利的双寡头公司之间的单边和交叉许可决策，考察了知识产权执法对均衡结果和福利的影响。在双方可能签订单边许可/交叉许可，实现双寡头有效社会剩余的条件下，得到了侵权方的模仿成本和原告公司胜诉概率的条件。较少

Firstly, we examine the effect of enforcement of intellectual property rights (IPR) on the equilibrium outcome and welfare through licensing between duopolistic firms with patents of two complementary technologies. We explore a condition on the extent of enforcement of IPR and the litigation cost of the infringer firm under which inefficient/ efficient social surplus of monopoly/duopoly realizes.Secondly, we construct a three country international trade game model which are composed of two (one developed and another developing) exporting countries' firms and one importing country. By dealing with licensing of developed country's firm technology with IPR, exhaustion of IPR and litigation for infringement of her IPR, we derive a sub game perfect Nash equilibrium.Thirdly, we examine how parallel importation influences pharmaceutical innovation and the welfare of the economy, when cross national drug price differentials occur not only because of demand elasticity based factors, but governm … More ental drug price control based factors. By explicitly considering the governmental drug price control based factors, we show that parallel importation may enhance pharmaceutical innovation, under some conditions on the bargaining power of a foreign government and the price elasticity of demand in the foreign market. We also show that the increase in R&D induced by parallel imports may even increase the consumer surplus of a country with high demand elasticities and which could face relatively low drug prices, if parallel imports were not allowed.Fourthly, we examine the effect of enforcement of IPR on the equilibrium outcome and welfare through unilateral and cross licensing decisions between duopolistic firms with patents of two complementary technologies. We find the conditions on both the imitation cost of the infringer and the probability of the accuser firm winning the lawsuit under that a unilateral licensing/ a cross licensing may be contracted between them, and efficient social surplus of duopoly realizes. Less