最优专利制度研究

本文构建了一个动态一般均衡模型来研究最优专利长度和最优专利宽度的问题。研究结论表明,最优的专利长度和专利宽度都是有限的。专利长度的增加会通过促进创新来提高社会福利水平,同时,也会导致市场扭曲,从而降低社会福利水平,但随着专利长度的不断增加,前者的效应会小于后者的效应,因此,有限的专利长度是最优的。有效的专利宽度应该一方面使得模仿产品的质量水平不要太低,从而保证模仿产品对专利产品形成潜在的威胁,逼迫专利产品的价格低于垄断价格,减小市场扭曲;另一方面使得模仿产品的质量不要太高,从而保证专利产品能够制定较高的垄断价格,促进创新。     

SPECIAL INTEREST POLITICS AND INTELLECTUAL PROPERTY RIGHTS: AN ECONOMIC ANALYSIS OF STRENGTHENING PATENT PROTECTION IN THE PHARMACEUTICAL INDUSTRY

Since the 1980s, the pharmaceutical industry has benefited substantially from a series of policy changes that have strengthened the patent protection for brand-name drugs as a result of the industry's political influence. This paper incorporates special interest politics into a quality-ladder model to analyze the policy-makers' tradeoff between the socially optimal patent length and campaign contributions. The welfare analysis suggests that the presence of a pharmaceutical lobby distorting patent protection is socially undesirable in a closed-economy setting but may improve social welfare in a multi-country setting, which features an additional efficiency tradeoff between monopolistic distortion and international free riding on innovations.     

Dynamic analysis of patent policy in an endogenous growth model

In this paper, we explore the dynamic properties of an endogenous growth model with finite patent length. We show that there exists a unique equilibrium growth path and that this path exhibits damped oscillations in contrast to the equilibrium path of an endogenous growth model with infinite patent length. We also examine the effects of patent policy on social welfare and show that infinite patent length does not maximize social welfare. Furthermore, we show that, in a growth model that does not exhibit scale effects, a finite patent length maximizes social welfare on the balanced growth path.     

Effects of a blocking patent on R&D with endogenous survival activities

This study analyzes the effect of strengthening patent protection for innovation and economic growth by introducing a blocking patent into the endogenous growth model developed by Furukawa (Econ Lett 121(1):26–29, 2013a), which features survival activity of patent holders in the R&D sector with a variety-expansion model. Results show that strengthening patent protection can raise the economic growth rate and social welfare through an endogenous survival investment. Additionally, this study examines the effects of increasing subsidies for R&D. We find that increasing R&D subsidy rate can negatively affect economic growth and social welfare because of the investment for survival activities. This result shows the novel role of a blocking patent in determining innovation effects of R&D subsidies. Furthermore, we analyze the effect of patent breadth which is another patent instrument in this model on innovation and economic growth. Results show that the growth and welfare effects of the profit-division rule and the subsidy rate for R&D may vary with the size of patent breadth.     

专利保护宽度和累积创新竞赛中的信息披露

该文将专利保护宽度定义为累积创新厂商之间的许可比率,考察其对累积创新竞赛中厂商信息披露决策的影响.我们发现:强的专利保护宽度有利于信息披露,但其对社会福利和技术进步率的影响却呈近似的倒U型,故在不同的情况下都存在一个专利保护宽度的最优取值区间.与事后许可相比,事前许可能在反托拉斯法的框架下导致社会福利的帕累托改进.如果双方对专利诉讼的结果具有相同的预期,则专利保护宽度的确定和实施就是无成本的.     

Optimal Privatization and Economic Growth in a Schumpeterian Economy

This paper analyzes the growth and welfare effects of the privatization of public firms in a Schumpeterian growth model. Two alternative definitions of privatization are proposed in our model. The first is the ratio of mixed R&D firms’ equity shares owned by the household, which is dubbed vertical privatization. The second is the number of unmixed R&D firms, which is called horizontal privatization. We find that, under both definitions, privatization is beneficial to economic growth while the effect of privatization on social welfare is ambiguous. Accordingly, our analysis reveals that a partial privatization could be an optimal policy. Moreover, we also discuss how the extent of patent protection is related to optimal privatization.     

Licensing to a durable-good duopoly in patent litigation

Incorporating patent litigation into a durable-good duopoly model, we revisit the optimal licensing contract on a cost-reducing innovation. We find that both the optimal licensing contract and the innovator's licensing revenue are closely related to the patent's strength, i.e., the probability it would be found valid if tested in court. It is shown that, for a relatively weak patent (patent's strength is low), it's optimal for the innovator to charge the royalty rate as high as possible coupled with a negative fixed fee. But for a relatively strong patent (patent's strength is high), contract involving the combination of a medium level royalty rate and a positive fixed fee is optimal. We also discuss how the patent's strength affects the social welfare of a patent. Finally we present two policy suggestions that may alleviate the social welfare loss raised by the licensing of weak patents.     

Does intellectual monopoly stimulate or stifle innovation?

This study develops an R&D-based growth model with vertical and horizontal innovation to shed some light on the current debate on whether patent protection stimulates or stifles innovation. We analyze the effects of patent protection in the form of blocking patents. We show that patent protection changes the direction of innovation by having asymmetric effects on vertical innovation (i.e., quality improvement) and horizontal innovation (i.e., variety expansion). Calibrating the model and simulating transition dynamics, we find that strengthening the effect of blocking patents stifles vertical innovation and decreases economic growth but increases social welfare due to an increase in horizontal innovation. In light of this finding, we argue that in order to properly analyze the growth and welfare implications of patents, it is important to consider their often neglected compositional effects on vertical and horizontal innovation.     

技术扩散模型中的发展中国家最优专利保护

本文在Barro and Sala-I-Martin(1997)的技术扩散模型基础上,构建了一个Ramsey问题模型讨论发展中国家内生的动态最优专利保护问题。本文给出了Ramsey问题的均衡解并讨论了其动态特征,克服了现有文献只用比较静态方式分析讨论外生最优专利保护政策的缺陷。本文的主要结论是,发展中国家在发展早期阶段,理应设定相对较低的专利保护程度,然后随着经济成长不断地提高专利保护水平,但其长期的稳态专利保护水平有可能比发达国家高,也可能比发达国家低。     

Patent Policy in an Endogenous Growth Model

We investigate how the patent policy affects economic growth and social welfare based on an endogenous growth model with R&D activities. We show that the patent length that maximizes the social welfare is finite. Moreover, by introducing compulsory licensing, we also show that the patent length that maximizes the social welfare is not infinite even if the royalty rate can be controlled. Received June 29, 2001; revised version received February 5, 2002 Published online: February 17, 2003 We wish to thank two anonymous referees for their constructive comments. We also thank Akira Yakita for his helpful comments.     

On Welfare Criteria and Optimality in an Endogenous Growth Model

In this paper, we explore the consequences for optimality of a social planner adopting two different welfare criteria. The framework of analysis is an overlapping generations model with physical and human capital. We first show that, when the social welfare function is a discounted sum of individual utilities defined over consumption per unit of natural labor, the precise cardinalization of the individual utility function becomes crucial for both the characterization of the social optimum and the policies that support it. Also, decentralizing the social optimum requires an education subsidy that is definitely positive, but its size depends in a determinant way on the aforementioned cardinalization. In contrast, when the social welfare function is a discounted sum of individual utilities defined over consumption per unit of efficient labor, the precise cardinalization of preferences becomes irrelevant. More strikingly, along the optimal growth path, the education subsidy is negative, i.e., the planner should tax rather than subsidize investments in human capital.     

Patent claims and economic growth

This study introduces a blocking patent on horizontal R&D into the endogenous growth model of Chu et al. (2012), which features a blocking patent on vertical R&D. Results show that strengthening patent protection on horizontal R&D promotes vertical innovation (quality improvement) but hinders horizontal innovation (variety expansion). This effect of a horizontal blocking patent on directionality of innovation is opposite to that of the vertical blocking patent analyzed by Chu et al. (2012). Results also show that under mild conditions, strengthening a blocking patent on horizontal innovation as well as on vertical innovation can increase economic growth and social welfare.     

Resource-grabbing by status-conscious agents

We introduce a dynamic model of resource-grabbing by status-conscious agents, i.e., agents value not only their absolute consumption levels, but also the relative status within their reference group. We explore the effect of the concern for relative consumption on the growth rate and the welfare of an economy where agents appropriate from a common property resource. Our model shows that the greater is agents' concern about their relative status, the more aggressively they tend to behave. Consequently, social welfare is lower because the growth rate of the public asset is reduced due to higher extraction rate. We also consider the effect of increased heterogeneity, and show that social welfare decreases as the distribution of status-consciousness among agents widens.     

A welfare analysis of global patent protection in a model with endogenous innovation and foreign direct investment

This paper constructs a North–South quality-ladder model in which foreign direct investment (FDI) is determined by the endogenous location choice of firms, and examines analytically how strengthening patent protection in the South affects welfare in the South. Strengthening patent protection increases the South's welfare by enhancing innovation and FDI, but it also allows the firms with patents to charge higher prices for their goods, which decreases welfare. However, the model shows that the former positive welfare effect outweighs the latter negative effect. Moreover, introducing the strictest form of patent protection in the South, that is, harmonizing patent protection in the South with that in the North, may maximize welfare in the South as well as in the North. Further, a similar result can also be obtained in a nonscale effect model.     

累积创新框架下的知识产权保护研究

本文通过构建累积创新框架下的拍卖模型来探讨知识产权制度的社会福利效应,比较各种具体制度的效率及在各种特殊的产业中的应用保护。基于存在领先厂商情况下累积创新过程中的创新竞赛问题的分析,可以得到三种不同策略情形下的社会福利函数,并确定知识产权保护程度的适用范围。研究结论的应用扩展表明:以生物技术、电子和医药等为主的行业,适用比较严格的保护制度进行保护,如专利制度;以计算机软件、音乐、书籍和期刊等为主的行业,适用比较宽松的保护制度进行保护,如版权制度。     

国际资本流动“突然停止”、消费平滑与最优外汇储备持有量*

通常认为外汇储备具有抵御外部冲击、平滑居民消费、增进社会福利的作用。循此逻辑,文章构建了三部门模型模拟了货币当局面临资本流动“突然停止”时,出于平滑消费目的的最优储备持有行为。研究发现：中国静态最优外汇储备量约占GDP的1926%;中国实际储备与最优储备的差额自2010年起稳定在18万亿美元;最优外汇储备量与“突然停止”发生概率及其导致的产出损失、短期外债规模、居民存款规模及危机时的资产置换比率、风险规避程度正相关,与银行备付金比率、国际风险溢价程度负相关;从危机应急的角度看,提高银行备付金比率、控制居民存款置换外币比例能有效节约外汇储备,但从长远来看控制国内短期外债规模、确保银行稳健运营才是应对国际资本“突然停止”风险的关键。     

The Immigration Policy Puzzle

This paper revisits the puzzle of immigration policy: standard economic theory predicts that free immigration improves natives' welfare, but (with few historical exceptions) an open door policy is never implemented in practice. What rationalizes the puzzle? We first review the model of immigration policy where the policy maker maximizes national income of natives net of the tax burden of immigration. We show that this model fails to provide realistic policy outcomes when the receiving region's technology is described by a standard Cobb–Douglas or CES function. Then we describe three extensions of this basic model that reconcile theory with evidence. The first introduces a cost of integration of the immigrant community in the destination country; the second takes into account the policy maker's redistributive concern across different social groups; the last extension considers positive spillover effects of (skilled) migrants on the receiving economy.     

Commercialization,renewal, and quality of patents

One of the major reasons why inventors are awarded patents by governments is they encourage R&D investments and commercialization of inventions. If the patent holder commercializes his/her invention, he/she has stronger incentives to retain the patent. The purpose here is to empirically analyze the relationship between commercialization and the renewal of patents. At the same time, I take into account defensive patent strategies (e.g. deterring competitors from utilizing the patent) and pointedly ask if there are any third factors (quality of the patent) that affect the commercialization and renewal decisions. Using a detailed database of Swedish patents, I utilize a survival model to estimate how commercialization influences the patent renewal decision. Basic results show not only that commercialization and defensive strategies increase the probability a patent will be renewed, but also that quality influences commercialization and renewal decisions. When controlling for the endogenous commercialization decision, there is still a strong positive relationship between commercialization and renewal of patents. Thus, given the quality of the patent, if the owner decides to commercialize the patent on the margin, this leads to longer survival of the patent. With regard to commercialization modes, there is some evidence that licensed patents and patents commercialized in original and new firms – but not acquired patents – survive longer than non-commercialized patents. Looking more closely at the contracts of acquired and licensed patents, contracts with both variable and fixed fees – but not contracts with either variable or fixed fees – survive longer than non-commercialized patents. However, the analysis about modes and contract terms does not take into account the endogeneity problem.     

Effects of blocking patents on R&D: a quantitative DGE analysis

What are the effects of blocking patents on R&;D and consumption? This paper develops a quality-ladder growth model with overlapping intellectual property rights and capital accumulation to quantitatively evaluate the effects of blocking patents. The analysis focuses on two policy variables (a) patent breadth that determines the amount of profits created by an invention and (b) the profit-sharing rule that determines the distribution of profits between current and former inventors along the quality ladder. The model is calibrated to aggregate data of the US economy. Under parameter values that match key features of the US economy and show equilibrium R&;D underinvestment, I find that optimizing the profit-sharing rule of blocking patents would lead to a significant increase in R&;D, consumption and welfare. Also, the paper derives and quantifies a dynamic distortionary effect of patent policy on capital accumulation.     

基于CGE模型的环境税优惠政策的环保效应分析

通过建立一个CGE模型,并对该模型在存在和不存在环境税优惠政策两种场景下的社会产出、产品供应和社会福利状况进行模拟分析,考察环境税优惠政策的环保效应。结果表明,环境税的税收减免在长期内对社会福利的影响不大,但是,它却会对环境税的环境保护效果产生较大的负面影响。在使用税收减免工具时,政府要从社会福利和环境保护、能源使用等方面加以考虑,避免社会总福利的净损失。