外部性的本质与分类

外部性概念至今仍模糊不清,其原因就在于研究的外部性对象并不一致。从系统论出发,以行为方为核心,通过其影响范围的延伸,将外部性划分为科斯外部性、马歇尔外部性和庇古外部性三种类型,进一步明晰了外部性的轮廓,区分了简单外部性和复杂外部性。在此基础上,揭示了外部性的本质,即受影响方的决策非参与性和缺乏有效的反馈机制。明确了外部性的定义,同时引入外部性系数,将外部性研究从定性研究引向定量研究。     

中国银行业竞争的外部性经济学溯源

中国金融业全面对外资开放,银行业的竞争格局面临重塑.分析了中国银行业竞争态势,揭示了中外银行业竞争格局异同的深层文化因素和外部性理论的起源及其在金融产业经济中的发展过程,提出外部性理论演进对中国银行业竞争的启示.     

Prudence and prevention: an economic laboratory experiment

In an economic laboratory experiment, we study the relationship between prudence and prevention in general decision situations. Previous theoretical research on this relationship posits a negative impact of prudence on the optimal level of prevention. Overall, we find both risk-averse and prudent behaviour among our subjects. Moreover, prudent subjects chose significantly less prevention than nonprudent subjects, confirming the theoretical results of one-period models in the literature. Our findings might have implications for health policy if prudence – rather than irrational decision behaviour, as previously assumed – is responsible for low levels of preventive effort.     

浅析自然资源利用中的代际外部性问题

自然资源开发利用中存在外部性问题, 本文在传统外部性理论的基础上, 提出了代际外部性的概念, 并对其种类、表现、产生原因、特点等进行了阐述。     

Is Aging Harmful to the Environment?

How does aging affect the environment? We analyze this question using anoverlapping generations model featuring uncertain lifetimes andenvironmental externalities. We show that whether aging is harmful to theenvironment depends on the curvature of utility function, which ismeasured by the degree of relative risk aversion. We also explore theimplication of the results for environmental policy in an aging society.     

Time Preference, Stock Externalities and Strategic Reactions

This paper examines the relationship between the rateof time preference and strategic reactions in dealing with climate change caused by anthropogenic greenhouse gas (GHG) emissions. Treating climate change as stock externalities, the RICE model (Nordhaus and Yang [1996]) is employed in this paper for simulation studies. The simulation results show that when regions' rate of time preference in evaluating climatechange is sufficiently low, the paths of efficient GHGemission reduction measurement and the inefficient Nash equilibrium outcome are close. The paper also provides general interpretations of such phenomena. Finally, the implications of a low rate of time preference on GHG emission reduction policies are discussed.     

“Probability of risk aversion” and other applications of derivatives of the certainty equivalent

“Probability of risk” aversion is principally concerned with reactions to scaling up of probabilities of non-zero values of a non-positive random variable by a common factor. Decreasing probability-of-risk aversion is defined and shown to be equivalent to ordinary risk aversion. Implications of this for insurance are pointed out. The sort of scaling involved is the same as that involved in “self-protection,” and it is shown that, for any expenditure on self-protection, say x, a concave utility function will prefer a coinsurance policy, costing x, which leaves probabilities unchanged, but scales down loss amounts by the same proportion as probabilities are scaled under self-protection. Properties of several comparative concepts of decreasing risk aversion are established. Derivatives of the certainty equivalent (CE) are used to elucidate well-known comparative static results in models of expected utility maximization. Finally, the study proves that concavity of the CE implies convexity of the coefficient of absolute risk aversion and examines the role of curvature of the CE in exploring relationships between properties of risk vulnerability, properness, and standardness.

电信网络外部性的一个注释及管制实践含义

网络外部性的存在使相关利益主体权利边界模糊,从而限制了电信网络竞争业务领域的可竞争性,同时理论上网络效应与网络外部性的混同,使管制政策与工具选择无力消除外部性,反而使现有的分拆式结构管制政策本身出现矛盾.本文的意义在于为网络性产业的合理管制路径提供一个基于外部性视角的理解.     

The problem of the uninsured

The problem of the uninsured cannot be fully understood without considering the role of non-market alternatives to ‘market insurance’ called ‘self-insurance’ and ‘self-protection’ (SISP), including the public ‘health care safety-net’ system. We tackle the problem by formulating a ‘full-insurance’ paradigm that accounts for all four interacting insurance measures. We apply two versions of the full-insurance model to estimate, via calibrated simulations, the impacts of SISP on the fraction of uninsured, health spending, and health levels, and to assess how the mandated Affordable Care Act might affect these outcomes in comparison with the CBO projections in 2010. The results indicate that policy analyses which overlook the role of the real price of market insurance relative to the shadow prices of SISP in determining the decision to insure can grossly distort the capacity of mandated reforms like the ACA to insure the uninsured, contain overall health care costs, and improve health and welfare outcomes.     

Network Externality and the Coordination Problem

We show that Rohlfss (1974) model is a special case of a spatial monopoly model á la Hotelling (1929) with uniform consumer distribution and quadratic transportation costs, where location is exogenous and the good yields no intrinsic utility. By relaxing these assumptions, we prove that the coordination problem typically thought to affect markets for network goods may not arise in general. Endogenizing location makes it easier for the monopolist to extract consumer surplus but also to cover the entire market. We also show that the main conclusions remain qualitatively unmodified if consumer distribution is triangular.revised version received September 16, 2003     

论传统外部性理论解决环境代际外部性的失效

代际外部性问题主要是人类代际之间行为的相互影响,尤其是前代对后代、当代对后代的影响。在解决代际外部性上,施害者、受害者和政府生活在不同的时空中,新古典方法几乎就无能为力。产权的界定是在产权主体存在的前提下进行的,所以产权在代际进行界定是不可能实现的,所以通过科斯定理来消除代际的外部性也行不通。     

Corrective Taxes under Oligopoly with Inter-Firm Externalities

Pollution externalities between polluters should be taken into account in the design of corrective taxes. When the externalities are substantial and/or the number of polluters is large, the effluent levies on these firms do not necessarily result in a deadweight loss. Consequently, the second-best tax exceeds the marginal social cost of pollution. A more general rule is that the tax rate should be greater than the marginal social cost of pollution if and only if a marginal increase in the tax rate results in opposite effects on the changes of equilibrium emission level and output.     

环境治理的经济学分析

环境资源和环境治理具有公共物品性和外部性,这导致了环境资源的过度使用和环境治理供给不足。但是市场机制无法自行解决这些困境,因此政府有必要采取措施解决。常用的经济学方法有庇古税、产权界定和国家规制等方法,但是这些方法存在一定的缺陷,应当有选择性地使用。     

闲暇时间与经济增长--兼对中国数据的实证检验

文章放宽了国外对闲暇研究的假设条件,突出考虑闲暇时间对人力资本形成的作用和对技术进步的外部性,将闲暇时间引入增长模型研究了闲暇与增长的动态关系,并对中国1981～2003年的经济数据进行了实证检验.实证检验结果表明,健康的闲暇活动能促进经济增长,但工业化阶段居民较低的闲暇偏好会拉低经济增长率,因此总体上闲暇时间对我国经济增长展现出微小的负作用.为此文章提出,应在加大精神文明建设力度的同时,合理安排契合本国经济发展阶段的公休假制度.     

水资源管理的外部性及其校正策略研究

水资源管理的外部性效应有三种校正策略：法律校正策略、市场校正策略、政府校正策略。在法律校正策略的基础上，应该将市场策略和政府策略相结合。只有将多种手段有机结合，协调互补，才能在水资源管理中发挥最大的效用，兼顾到经济目标、社会目标和生态目标。     

Endogenous timing in the switching of technology with Marshallian externalities

We analyze endogenous timing in the switching of technology. Each user chooses when to purchase a new product which embodies new technologies characterized by Marshallian externalities. The technological switch occurs when a large number of users purchase new products. Under complete information, multiple market equilibria exist, and one of the equilibria in which technological switching occurs is efficient. However, if we introduce even a small amount of uncertainty, the switch is delayed in the unique equilibrium under perfect competition, resulting in a loss of social welfare. The market power of a monopolistic supplier of new products alleviates this inefficiency.     

垄断竞争的电信业定价策略研究

讨论垄断竞争条件下电信业定价策略,对理解电信运营商的竞争行为、制定电信业竞争政策有重要的意义。本文将呼叫外部性引入模型,考察了呼叫方内部化接听方效用条件下企业定价策略,从而扩展了目前理论内容和结论。研究表明：当呼叫方内部化接听方的效用时,在线性定价条件下,电信运营商仍然会通过提高接入费进行合谋;在非线性定价条件下,由于电信运营商可以利用固定费进行市场份额的争夺,电信运营商不再有利用接入费进行合谋的动机;在基于终接网络的价格歧视条件下,当消费者接听效用接近于呼叫效用时,电信运营商将会通过制定无穷大的呼叫异网价格来获取更大的市场份额,因此网络联接发生了中断。