从"公地悲剧"到"反公地悲剧"

“反公地悲剧”是与“公地悲剧”对应的一个经济学概念 ,“悲剧”的产生也与产权的界定有关。目前我国正在进行并日益深化的经济体制改革 ,很多领域都由于产权的支离破碎而带有明显的“公地”特性 ,也因此产生了大量的“反公地悲剧”。在深化国有资产管理体制改革过程中 ,应当积极探索新的模式重新整合产权 ,提高国有资产使用效率 ,避免“反公地悲剧”的重演。     

The Tragedy of the Commons Revisited

The Malthus–Hardin tragedy of the commons is formulated as a dynamic game between "clans". At each date a member of a clan desires more newborns of her/his type and more current consumption, harvested from the commons. Equilibrium in the dynamic game yields a steady state level of per capita consumption and a steady population level for each clan (births equal deaths). Four outcomes are obtained, depending on the assumptions about the discount rates of members of a clan and about the mode of competition for "large populations" for each clan. Lack of property rights for agricultural land in the commons leads to equilibrium with excessive populations and low per capita consumption.     

General Equilibrium Tragedy of the Commons

Many poor economies depend on open access resources for their livelihoods. Households in resource-based economies allocate their time and other factors between resource extraction and other activities. As a result, factors may shift from one sector to another as marginal returns change. This has two important implications. First, it implies potentially strong linkages between resource and non-resource sectors. Second, it means that unmanaged resources cause inefficient allocations of inputs across all sectors, and the effects of resource management spill into other sectors. We construct a local general equilibrium model that accounts for inputs that over-allocate to an open access resource and create a general equilibrium tragedy of the commons. This model describes resource rent dissipation more adequately in economies with mobile factors than a model with slowly dissipating rents. Perfectly mobile factors dissipate rent in every period, but endogenous wages cause labor and capital allocations to change with the resource stock. We use the model to illustrate medium-run impacts of a limit on capital in an artisanal fishery in Honduras. Simulation results reveal that fishery management has economy-wide impacts on prices and wages. Managers in developing countries thus should consider these linkages when implementing policies to conserve fish stocks.     

Stock Externality vs. Symbiosis in a Forest-Air System

Stock externalities and ecological interaction have similar equilibrium effects. The influence on the dynamics of an ecosystem, however, is quite different. The different effects are laid out theoretically in the context of a forest-air model. We compare a centralized, welfare-maximizing policy and decentralized policies. Finally, we numerically simulate the dynamic differences between stock externalities and ecological interaction.     

Information Structure and the Tragedy of the Commons in Resource Extraction

Synopsis This paper considers the well-known Levhari-Mirman discrete-time model of resource extraction, and investigates the effects of the information structure of the dynamic game – open-loop, Markovian or history-dependent – on the equilibrium consumption path and the overall utility of the agents. Due to the special structure of the model, the open-loop regime yields a Pareto-optimal outcome. The Markovian regime leads to the most pronounced version of the tragedy of the commons. History-dependent behavior yields an outcome set that is intermediate between the other two cases, and that may include the Pareto-optimal outcome in some cases. The level of efficiency of equilibrium behaviour is thus U-shaped as a function of the level of information the agents’ extraction strategies are based on. The analysis suggests that in environments characterized by a dynamic (and no market) externality, forcing agents to commit to open-loop behavior would constitute welfare-improving regulation.     

Trade Gains, Paretian Transfer and the Tragedy of the Commons

Consider trade liberalization between two countries, each of which produces two private goods and provides on a voluntary basis one public good (the common). In these circumstances, what are the consequences of trade liberalization on the production of the public good and on welfare in both countries? Using a Ricardian framework, we first show that the opening of trade increases the opportunity cost of producing the public good in both countries and will therefore reduce the aggregate supply of the public good. On the other hand, at the autarky equilibrium, only one country supplies the public good, the other “free rides”. The analysis of the welfare incidence of the opening of trade then reveals that the country which provides the public good under autarky always enjoys a welfare gain from trade while the free rider under autarky does not unless the terms of trade are sufficiently in its favour to compensate for the reduction in the supply of the common. Finally, if all countries involved in trade liberalization can without cost coordinate their supplies of the common, then the implementation of the first-best outcome is shown to be possible with a conditional Paretian transfer scheme.     

基于网络外部性的上架费博弈分析

上架费作为制造商和零售商博弈的重要工具,在具有网络外部性的网络零售市场上其决定机制更加复杂。从网络销售市场的网络外部性出发,构建模型分析三种市场结构下上架费的由来及均衡确定。发现,网络外部性与上架费和产品价格都成反比;网络零售商的市场势力并不通过上架费的变化直接体现,而是通过产品价格的变化间接体现;网络外部性作为网络零售商利润的重要组成部分,与网络零售商的上架费收入成反比。     

协调博弈均衡随机稳定性的研究现状与展望

协调博弈均衡选择不仅依赖于博弈支付,更重要的是依赖于参与人之间复杂的行为预期过程,它是继囚徒困境博弈模型之后又一被广泛研究的博弈类型,本文基于随机稳定性思想,结合已有的研究文献,基于实验经济学的研究结果阐述了除博弈支付之外还有许多其他影响均衡稳定性的因素,在此基础上,进一步论述了相关理论模型的研究结论及其存在的缺陷,因此,要更现实地研究协调博弈均衡的稳定性,就需要加入除博弈支付之外的其他因素,最后,文章结合实验研究及理论模型提出了协调博弈均衡稳定性研究的思路与方向,为学者们进一步研究提供了新的视角。     

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。     

我国股市中政府与投资者的行为博弈分析

中国股票市场自建立至今，已经历了多次大幅震荡。由于中国股市的建立是自上而下的强制性制度安排，且政府集上市公司股权的主要所有者和市场管理者于一身的特殊身份，造成了政府要同时承担发展和监管股市的双重职能，因此“政策市”效应成为影响股市波动的一个关键性因素，其作用过程是政府与投资者之间进行一场信号博弈。本文通过对该博弈进行的分析，揭示了政策效应在我国股票市场上的作用机理。并根据所做的分析，对政策效应主导下的股票市场的效率做出了评价。     

外部性理论价值功能的重塑——从外部性理论遭受质疑和批判谈起

外部性理论一直受到质疑和批判.该理论核心概念模糊不清,价值功能定位错误,不能很好解决其试图解决的实际问题,若不对其价值功能加以重塑,确实存在被交易成本和合约理论取代的危险.将外部性理论的价值功能定位于:揭示侵害事实的客观存在;使公平与效率、政府于预与自由市场获得更优或最优均衡.作此重塑,将使该理论不仅具有重要的实践意义,而且具有重要的学术价值.     

Individual Decision Making in a Negative Externality Experiment

The experimental treatments analysed in this paper are simple in that there is a unique Nash equilibrium resulting in each player having a dominant strategy. However, the data show quite clearly that subjects do not always choose this strategy. In fact, when this dominant strategy is not a focal outcome it does not even describe the average decision adequately. It is shown that average individual decisions are best described by a decision error model based on a censored distribution as opposed to the truncated regression model which is typically used in similar studies. Moreover it is shown that in the treatments where the dominant strategy is not focal dynamics are important with average subject decisions initially corresponding to the focal outcome and then adjusting towards the Nash prediction. Overall, 66.7% of subjects are consistent with Payoff Maximization, 27.8% are consistent with an alternate preference maximization and 5.6% are random.     

中国股市惯性交易策略的实证研究

本文运用随机占优理论对中国股票市场上的赢家组合、输家组合以及惯性交易策略的有效性进行了实证检验,研究发现在排序期中赢家组合和输家组合的年度收益率分别为48.9%和-39.8%,但持有期的赢家组合和输家组合的年度收益率的绝对值低于排序期,分别为9.76%和-0.89%.运用Barrett-Donald KS的二阶和三阶随机占优检验结果也显示对于不同的样本排序期和持有期,赢家组合确实随机占优于输家组合,从而验证了中国股票市场上"强者恒强、弱者恒弱"的股市定律及"追涨杀跌"交易策略的有效性.     

基于进化博弈链结构的股票市场非理性泡沫测算问题研究

本文针对股市噪声不断累积,强化和排除的循环过程,基于股票市场对称进化博弈链结构模型,讨论了上海证券交易所正常情况下和极端情况下采用噪声交易策略比例的博弈进化过程和进化稳定策略,并将这个动态比例过程扩展到改进的DSSW模型中,据此测算出上证股市非理性泡沫大小.研究发现,在一定条件下,市场中的噪声交易者越多,风险资产价格非理性泡沫成分越大,波动越剧烈.本文的工作为股市泡沫的分析和测度提供了新的思路和工具.     

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。     

中国股票市场机构与散户的均衡策略及实证研究

证券市场作为一个政府、交易所、上市公司、机构和散户多方参与的博弈竞技场,各方必然要观察各参与方的行为策略并据此制定己方的行动战略。由于目前中国证券市场尚无做空机制,且股票供应紧俏,很多股票交易中都有机构主力参与的痕迹。机构利用信息和资金优势,在政策法律允许的范围内,尽力推高股价以诱使散户追涨是其最优策略的理性选择。而散户在信息严重不对称的劣势下,其后验信念的修正往往会受到机构信号的误导,博弈所要求的最优策略行动实际上是很难达到的,故个体投资者无疑是证券市场最大的受害者。     

农田水利PPP项目的运行机制——基于随机演化博弈

首先,将演化博弈理论应用于农田水利PPP项目运行机制中,研究并建立了农田水利PPP项目运行阶段项目公司和农户策略选择的演化博弈模型,得到了双方的支付矩阵。然后,引入高斯白噪声反映农田水利PPP项目运行过程中的随机干扰(如政府政策变化、信息不对称以及极端天气等),建立不确定性环境下农田水利PPP项目的随机演化博弈模型,并分析了随机扰动下项目公司和农户双方策略选择的稳定性。最后,运用仿真软件对模型进行情景模拟,并针对不同情境下的仿真结果提出相应的对策建议。     

Equilibrium in a Market Game

This paper studies the equilibrium of an exchange economy with the same number of agents and commodities. It is shown that under rather mild conditions on demand the market have a price equilibrium—independently of the divisibility of the commodities. The result extends Gale’s equilibrium theorem for indivisible commodities to the case where some commodities are perfectly divisible. The proof is based on a topological lemma contained in previous paper of one of the authors.     

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.