Congestion games with mixed objectives

We study a new class of games which generalizes congestion games and its bottleneck variant. We introduce congestion games with mixed objectives to model network scenarios in which players seek to optimize for latency and bandwidths alike. We characterize the (non-)existence of pure Nash equilibria (PNE), the convergence of improvement dynamics, the quality of equilibria and show the complexity of the decision problem. For games that do not possess PNE we give bounds on the approximation ratio of approximate pure Nash equilibria.     

Reinforcement‐based vs. Belief‐based Learning Models in Experimental Asymmetric‐information Games

This paper examines the abilities of learning models to describe subject behavior in experiments. A new experiment involving multistage asymmetric‐information games is conducted, and the experimental data are compared with the predictions of Nash equilibrium and two types of learning model: a reinforcement‐based model similar to that used by Roth and Erev (1995), and belief‐based models similar to the ‘cautious fictitious play’ of Fudenberg and Levine (1995, 1998) These models make predictions that are qualitatively similar cycling around the Nash equilibrium that is much more apparent than movement toward it. While subject behavior is not adequately described by Nash equilibrium, it is consistent with the qualitative predictions of the learning models. We examine several criteria for quantitatively comparing the predictions of alternative models. According to almost all of these criteria, both types of learning model outperform Nash equilibrium. According to some criteria, the reinforcement‐based model performs better than any version of the belief‐based model; according to others, there exist versions of the belief‐based model that outperform the reinforcement‐based model. The abilities of these models are further tested with respect to the results of other published experiments. The relative performance of the two learning models depends on the experiment, and varies according to which criterion of success is used. Again, both models perform better than equilibrium in most cases.     

信息不对称下委托代理契约纳什实施性研究

针对代理人逆向选择导致委托人无法将契约与代理人类型状态直接关联的矛盾,研究了信息不对称下委托代理契约的纳什实施性问题。通过建立信号空间上的纳什均衡与有效配置的映射关系,将委托人契约与代理人状态联系起来,并以完全信息下委托人的最优契约和逆向选择下的次优契约为例,研究分析委托人契约纳什实施的性质,当且仅当委托契约满足激励相容约束时,才具备纳什实施的惟一性,该结果为实务契约设计逼近激励可行契约提供了新的途径。     

基于不同预期报价决策的电力市场动态演化及其混沌控制

基于市场参与者不同预期的报价决策方式,提出了考虑输电网约束的电力市场动态模型,即内嵌市场清算优化问题的差分动态模型.该模型刻画出发电方和需求方同时报价的不用决策行为,并准确反映出独立系统调度员ISO的统一市场清算过程,考虑了输电网固有物理特性所赋予电力市场的复杂约束.借助非线性互补函数,对应不同的输电网运行状态:阻塞和不阻塞,分析比较了电力市场处于Nash均衡、周期和混沌的经济表现.针对经济表现差的市场混沌态,提出电力市场状态和参数时滞反馈控制方法,给出电力市场由混沌到Nash均衡的调控措施和手段,从而为有效提高电力市场的经济效益提供了理论依据.     

基于共识程度的双体博弈纳什均衡拓展研究

首先对一般双体博弈的策略进行拓展,提出共识纳什均衡的概念,并证明其存在性;根据共识程度的降低提出其他3种拓展形式——近似共识纳什均衡、局部共识纳什均衡和局部近似共识纳什均衡,并举例进行说明;然后,对各种均衡形式下的合作效率进行分析和比较。研究表明,共识纳什均衡的利益分配是基于信息本身——竞争环境的特殊形式,它是具有效率的。其他3种形式均衡的效率低于共识纳什均衡,但仍高于双体博弈纳什均衡。共识纳什均衡和其他3种形式的均衡为参与人组织更具效率的合作提供了渠道和理论解释。     

基于DEA的两阶段系统中间产品公平设定研究

在由两个子决策单元串联组成的两阶段系统中,公平设定中间产品目标对确保和激励两阶段相互合作以达到整个系统的最佳性能至关重要.数据包络分析(DEA)作为系统绩效评估的一种非参数方法吸引了众多学者的注意;基于此方法,本文提出一个考虑公平关切的两阶段DEA模型用于设定两阶段系统中间产品目标,并证明据此模型获得的设定方案正是一个纳什讨价还价博弈的均衡解.     

The impact of related party transactions on earnings management: some insights from the Italian context

Related party transactions have become a key issue as a result of recent financial scandals. This study examines whether firms use related party transactions for earnings management, and then, whether they try to minimize detection through the format of related party transactions disclosure. Firstly, we analyze the association between related party transactions structure (types and parties involved) and the probability of reporting small earnings increase. Related party transactions may have significant impact on, and implications for, earnings management. According to the agency theory, related party transactions are used opportunistically, while the efficient transaction hypothesis argues that related party transactions meet the economic needs of the business. We next investigate the association between the probability of reporting small earnings increases through related party transactions and disclosure quality. Disclosure quality should be studied in relation to impression management and investor attention; this approach takes account of the idea that earnings management behavior may influence the quality of disclosure as a possible way of lowering conflict of interest. In line with the agency theory, our findings show that revenue related party transactions are more likely to be used to manage earnings than other types of transaction; related party transactions with ultimate parents are associated with lower probability of reporting small earnings increases compared to operations with other related parties. Lastly, our results confirm that the decision to engage in earnings management is related to lower disclosure quality.     

基于相对财富效用的多阶段投资组合博弈模型

现有投资组合优化模型普遍假设投资者之间是相互独立的，然而在实际投资过程中投资者往往是相互影响的，尤其是对于机构投资者而言，考虑这种相互影响显得尤为重要。本文基于多阶段投资组合理论和纳什均衡思想，考虑投资者决策之间的影响关系，以每个投资者自身终端相对财富的期望效用水平最大化为目标，构建了多阶段投资组合博弈模型，并给出了纳什均衡投资策略和相应值函数的解析解。最后，采用累计经验分布函数和确定性等价等指标，对纳什均衡投资策略与传统策略进行了比较，结果表明纳什均衡策略更具优越性。     

基于讨价还价模型的持股型供应链最优订货与定价策略研究

论文分析了风险规避型供应商和制造商组成的供应链系统，为了降低供应的不确定等因素，通过制造商投资供应商并持股的方式降低供应链的整体风险。构造均值-方差模型刻画制造商和供应商的风险偏好特征，并通过构建纳什讨价还价模型分析供应商和制造商的交易谈判过程。论文证明了纳什讨价还价模型存在唯一的均衡合同，并对均衡合同进行了比较静态分析，提出了可供实践企业参考的管理启示。     

网上交易中诚信交易激励机制设计

网上交易中日益增长的欺诈行为阻碍了人们参与网上交易的积极性.激励参与方在网上交易中诚信交易非常必要,而现有的简单反馈机制难以实现激励诚信交易的功能.提出了一种新的网上交易市场中激励诚信交易的机制——注册押金和交易保证金制度.该机制不仅把交易前的交易保证金与交易方信誉指数结合起来防范交易方欺诈,而且重构了每次交易可获得的信誉指数计算方法以激励交易方在长期中保持诚信.通过对该机制下交易方行为的博弈分析,证明了诚信不仅是单阶段博弈的纳什均衡策略,还是长期博弈的子博弈完美纳什均衡策略.最后,通过随机选取eBay市场的交易数据,对机制进行了模拟,并验证了其有效性.     

基于策略熵的博弈分析研究

通过建立博弈问题的信息论模型和定义不同类型博弈问题的策略熵,论证了纳什均衡与最大熵之间的内在联系:最大策略熵是纳什均衡的充分必要条件。这表明纳什均衡不仅是利益的均衡同时也是信息均衡的结果。在此基础上,给出了基于熵最大化准则的纳什均衡估计与精炼的方法。     

控股股东、代理问题与关联交易:对中国上市公司的实证研究

本文分析控股股东是否通过关联交易,转移上市公司资源、侵占小股东利益.对中国上市公司1999-2001年的关联交易的实证检验结果发现:由控股股东控制的公司,其关联交易显著高于无控股股东控制的公司;控股股东担任高级管理者的公司,其关联交易显著高于控股股东不担任高级管理者的公司;控股股东持股比例和控股股东在董事会中的席位比例越高,关联交易越多,这意味着控股股东确实能够借助关联交易转移公司资源、侵占小股东利益.     

A Dynamic Reinterpretation of Nash Bargaining With Endogenous Threats

This paper concerns the two‐stage game introduced in Nash (1953). It formalizes a suggestion made (but not pursued) by Nash regarding equilibrium selection in that game, and hence offers an arguably more solid foundation for the “Nash bargaining with endogenous threats” solution. Analogous reasoning is then applied to an infinite horizon game to provide equilibrium selection in two‐person repeated games with contracts. In this setting, issues about enforcement of threats are much less problematic than in Nash's static setting. The analysis can be extended to stochastic games with contracts.     

Efficient Repeated Implementation

This paper examines repeated implementation of a social choice function (SCF) with infinitely lived agents whose preferences are determined randomly in each period. An SCF is repeatedly implementable in Nash equilibrium if there exists a sequence of (possibly history‐dependent) mechanisms such that its Nash equilibrium set is nonempty and every equilibrium outcome path results in the desired social choice at every possible history of past play and realizations of uncertainty. We show, with minor qualifications, that in the complete information environment an SCF is repeatedly implementable in Nash equilibrium if and only if it is efficient. We also discuss several extensions of our analysis.     

Optimal Inattention to the Stock Market With Information Costs and Transactions Costs

Information costs, which comprise costs of gathering and processing information about stock values and costs of deciding how to respond to this information, induce a consumer to remain inattentive to the stock market for finite intervals of time. Whether, and how much, a consumer transfers assets between accounts depends on the costs of undertaking such transactions. In general, optimal behavior by a consumer facing both information costs and transactions costs is state‐dependent, with the timing of observations and the timing and size of transactions depending on the state. Surprisingly, if the fixed component of the transactions cost is sufficiently small, then eventually, with probability 1, a time‐dependent rule emerges: the interval between observations is constant and on each observation date, the consumer converts enough assets to liquid assets to finance consumption until the next observation. If the fixed component of transactions costs is large, the optimal rule remains state‐dependent indefinitely.     

Nash均衡、变分不等式和广义均衡问题的关系

主要讨论了Nash均衡问题(NE)与变分不等式(VI)和广义均衡问题(GEP)的关系.给出它们之间解的等价关系,以及与之相应的映射之间单调性的关系.研究结果为进一步研究Nash均衡、广义均衡问题理论及其算法提供了理论依据.     

Adoption of e‐Processes by Service Firms: An Empirical Study of Antecedents

This paper investigates empirically antecedents of the adoption of web‐based processes (e‐processes) by service providers. We examine whether rational efficiency (expressed by expected performance benefits and access to new markets), the bandwagon effect (expressed by external pressure), and barriers (both internal and customer related) influence Internet use for transactions (e‐transactions) and/or to extend the relationships between service providers and their customers (e‐CRM). The findings, based on a sample of 338 service firms, show that rational efficiency and the bandwagon effect drive both types of e‐processes. Conversely, only internal barriers have a negative impact on adoption of e‐processes, while barriers related to customers do not have a significant impact. These findings have important academic and managerial implications, given the limited evidence regarding the implementation of e‐processes in services.     

我国证券市场中的噪声交易研究——基于一个“机构噪声交易者—散户噪声交易者模型”的分析

本文从行为金融理论发展的大背景出发,以噪声交易作为研究主题。首先介绍了基于行为金融理论的噪声交易理论;接着简要介绍了噪声交易理论的基本模型—DSSW模型,为将其应用于我国证券市场的实证并提出一个改良模型做好理论铺垫;然后在DSSW模型的基础上,结合我国证券市场的实际情况,原创性地提出了一个我国证券市场机构噪声交易者一散户噪声交易者模型,以分析说明我国噪声交易者的生存机制及噪声交易对证券市场的影响,并得出相应的启示和政策建议。     

资产收益序列相依下的多阶段投资博弈模型

现有投资组合优化研究普遍假设投资者之间相互独立,且假定标的资产在不同阶段的收益序列不具相关性.然而在实际投资过程中,投资者往往是相互影响,资产收益序列也存在相依特征.基于多阶段投资组合优化和纳什均衡理论,利用相对绩效来刻画投资者之间的博弈现象,以每个投资者的相对终端财富的期望效用水平为目标,构建多阶段投资组合博弈模型.在资产收益序列相依情形下,给出了纳什均衡投资策略和相应值函数的解析表达式,以及纳什均衡投资策略与传统策略的关系.采用累计经验分布函数和夏普比率等指标,对纳什均衡投资策略与传统策略进行仿真比较,分析了纳什均衡投资策略随投资者反应敏感系数的变化趋势.结果表明:相比于传统的投资策略,当考虑竞争对手的相对绩效时,纳什均衡策略投资者更愿意冒高风险去追求高收益;并且投资者的反应敏感系数越大,其对风险的偏好程度也越高.     

Existence and Uniqueness of Maximal Reductions Under Iterated Strict Dominance

Iterated elimination of strictly dominated strategies is an order dependent procedure. It can also generate spurious Nash equilibria, fail to converge in countable steps, or converge to empty strategy sets. If best replies are well–defined, then spurious Nash equilibria cannot appear; if strategy spaces are compact and payoff functions are uppersemicontinuous in own strategies, then order does not matter; if strategy sets are compact and payoff functions are continuous in all strategies, then a unique and nonempty maximal reduction exists. These positive results extend neither to the better–reply secure games for which Reny has established the existence of a Nash equilibrium, nor to games in which (under iterated eliminations) any dominated strategy has an undominated dominator.