EQUILIBRIA IN NON-COOPERATIVE GAMES II: DEVIATIONS BASED REFINEMENTS OF NASH EQUILIBRIUM

In any Nash equilibrium no player will unilaterally deviate. However, many games have multiple Nash equilibria. In this paper, we survey some refinements of Nash equilibria based on the hypothesis that any player may consider a deliberate deviation from a Nash equilibrium vector while expecting other players to respond optimally to this deviation. The concepts studied here differ in the expectations players have about other players' responses to a deviation. This sort of deviations philosophy is predicated on the thought process of players. Therefore, the validity of a particular equilibrium concept to an economic model may depend upon the relevance of the thought process implied by the concept.     

Potential heterogeneity in target’s value and jump bidding in takeover auctions

This ticle analyses the pre-emptive jump bidding equilibrium in takeover auctions when bidders’ valuations of the target firm follow truncated normal distribution. It shows that potential heterogeneity of the targets’ value, measured by the standard deviation of the bidders’ valuation function, is especially important when it is small and, for extremely small values, the second bidder is almost always pre-empted. It also shows that, contrary to regular clock-style auctions, the increase in standard deviation may negatively affect the expected profit of the first bidder.     

The Political Economy of Xenophobia and Distribution: The Case of Denmark*

For the first time in some years, a conservative government came to power in Denmark in 2001, due primarily to the citizenry's disaffection with social‐democratic policies on immigration. We represent political competition in Denmark as taking place over two issues—the size of the public sector and immigration—and model political equilibrium using the party unanimity Nash equilibrium (PUNE) concept, which generates equilibria on multi‐dimensional policy spaces where parties form endogenously. By fitting the model to Danish data, we argue that citizen xenophobia may be expected to decrease the size of the Danish public sector by an amount between 12% and 36% of one standard deviation of the probability distribution of citizens' ideal points of the size of the public sector.     

Ownership and corporate wage policy: the signal and its strength

We argue that identification and proper specification of ownership links among firms is an important factor and is affecting firm performance on different dimensions. We focus on the corporate wage policy, where we show that firms with same stockholders have similar average labour costs after controlling for standard factors of the wage equation. Moreover, we propose new measures of stockholders’ ability to influence firms’ decision; signal and its strength. The signal measures stockholder’s preferences over a given corporate policy, while the strength function describes stockholder’s ability to influence a firms’ corporate policy.     

Peer Effects and Social Networks in Education

We develop a model that shows that, at the Nash equilibrium, the outcome of each individual embedded in a network is proportional to his/her Katz–Bonacich centrality measure. This measure takes into account both direct and indirect friends of each individual, but puts less weight to his/her distant friends. We then bring the model to the data using a very detailed dataset of adolescent friendship networks. We show that, after controlling for observable individual characteristics and unobservable network specific factors, a standard deviation increase in the Katz–Bonacich centrality increases the pupil school performance by more than 7% of one standard deviation.     

STOCK MARKET CRASH AND EXPECTATIONS OF AMERICAN HOUSEHOLDS

This paper utilizes data on subjective probabilities to study the impact of the stock market crash of 2008 on households' expectations about the returns on the stock market index. We use data from the Health and Retirement Study that was fielded in February 2008 through February 2009. The effect of the crash is identified from the date of the interview, which is shown to be exogenous to previous stock market expectations. We estimate the effect of the crash on the population average of expected returns, the population average of the uncertainty about returns (subjective standard deviation), and the cross-sectional heterogeneity in expected returns (disagreement). We show estimates from simple reduced-form regressions on probability answers as well as from a more structural model that focuses on the parameters of interest and separates survey noise from relevant heterogeneity. We find a temporary increase in the population average of expectations and uncertainty right after the crash. The effect on cross-sectional heterogeneity is more significant and longer lasting, which implies substantial long-term increase in disagreement. The increase in disagreement is larger among the stockholders, the more informed, and those with higher cognitive capacity, and disagreement co-moves with trading volume and volatility in the market.     

The single deviation property in games with discontinuous payoffs

We study equilibrium existence in normal form games in which it is possible to associate with each nonequilibrium point an open neighborhood, a set of players, and a collection of deviation strategies, such that at any nonequilibrium point of the neighborhood, a player from the set can increase her payoff by switching to the deviation strategy designated for her. An equilibrium existence theorem for compact, quasiconcave games with two players is established as an application of a general equilibrium existence result for qualitative games. A new form of the better-reply security condition, called the strong single deviation property, is proposed.     

Duopoly compatibility standards with partial cooperation and standards leadership

This paper presents a model of duopolists producing differentiated substitutes. Greater compatibility between the products causes each to have a greater demand. However, each firm has a most desired location in the product space (a most preferred technical standard); deviation from that standard in the direction of the rival's standard increases compatibility, but is costly. This paper presents the equilibrium outcomes for two products under Cournot rivalry, multiproduct monopoly, second-best standards-specification, and welfare maximization. The outcome associated with partial cooperation is examined. Then the Stackelberg model is used to derive the equilibrium conditions for output leadership and technical standards leadership. This model of technological externalities allows us to compare and evaluate different standards-specification processes.     

独立董事制度与中小股东利益保护

设立独立董事，对上市公司中小股东的利益保护能够起到一定的作用，但是绝不要过于依赖，第一，独立董事是经济人，在效用最大化行为原则和许多现实条件的约束下，独立董事难于与中小股东激励相容，独立董事积极保护中小股东利益的动力有限；第二，独立董事在董事会中，由于董事会的机制限制，独立董事保护中小股东利益能力也十分有限.本提出，保护中小股东的利益，关键要在如下三个方面下功夫；第二，健全公司股东利益保护的法制，特别是有关重大经营信息披露的时限与责任规定；第二，降低大股东持股的首位度，形成股东制约股东的机制；第三，加大对重大的股东侵权案件的查外，既追究侵权的法人机构的责任，更要追究当事的自然人违反诚信义务的民事责任和刑事责任。     

Estimating the elasticity of intertemporal substitution accounting for stockholder-specific portfolios

This article estimates the elasticity of intertemporal substitution using stockholder actual return experience. The approach is motivated by numerous data sources indicating that the median US stockholder has a portfolio composed of only three or four individual stocks, rather than a well-diversified portfolio as suggested by portfolio theory. Therefore, representing an individual stockholder portfolio by a proxy financial index (the common approach taken in the literature) may be too rough an approximation of investor behaviour and lead to biased results about risk aversion and intertemporal substitution. Eschewing the financial index methodology, our results support the standard representative agent assumption that there is a high degree of homogeneity in the elasticity of intertemporal substitution across stockholders with different wealth levels. Our findings have implications for models that assess the comovement between consumption and return on stocks.     

Product liability and the virtues of asymmetric information

This paper analyzes a two-period setup in which firms differ with respect to costs of care and may use care-taking to signal type to consumers, who are able to observe precaution taken only ex post. Applying the refinement of the intuitive criterion to the concept of the perfect Bayesian equilibrium, we establish a unique separating equilibrium for every share of harm borne by firms. For low levels of victim compensation, we show that (i) firms choose weakly higher care in a setting in which customers do not know the firms’ type than in a setting in which they do, and (ii) the deviation in precaution taken due to asymmetric information on firm type is welfare-improving.     

WELFARE GAINS AND LOSSES IN SUNSPOT EQUILIBRIA*

We study a standard two period exchange economy with one nominal asset. As is well known, there is a continuum of sunspot equilibria around each efficient equilibrium. A sunspot equilibrium is inefficient but some households may gain in sunspot equilibria relative to the efficient equilibrium. We show that a household's equilibrium utility level is either locally maximized or locally minimized at the efficient equilibrium, and derive a condition which identifies whether or not a household's utility is locally minimized or maximized.     

Minimum safety standard,consumers’ information and competition

This paper explores the effects of a standard influencing care choice with an endogenous market structure. Under duopoly, firms compete either in prices or in quantities. Firm(s) may increase the probability of offering safe products by incurring a cost. A standard may correct a safety underinvestment by firms. It is shown that the market structure (duopoly or monopoly) linked to the standard depends on the available information. Under perfect information about safety for consumers, the selected standard is always compatible with competition. The absence of standard due to safety overinvestment by firms only emerges under competition in quantities and a relatively low cost of safety improvement. Under imperfect information about safety for consumers, the selected standard often leads to a monopoly situation, essential for covering the cost of safety improvement. However, for relatively high values of this cost, a standard cannot impede the market failure arising from the lack of information.      

我国上市公司过度投资行为的识别

由于股东和经理之间存在信息不对称而产生的代理成本问题,使得经理有过度投资的倾向,但是原有过度投资的检验方法并未能准确地界定过度投资行为。本文在综合考虑项目投资的期限、投资的行业差异和投资收益情况因素后确定了过度投资行为的判断标准,在此基础上进行过度投资的识别可以更好地发现存在过度投资的企业,并为进一步研究过度投资的治理提供准确的数据支持。过度投资上市公司在负债比例、投资年度的收益以及是否处于战略扩张阶段等方面和其他上市公司存在显著差异。     

两大股权激励方式激励作用的比较研究——基于厌恶经理人的委托代理模型分析

笔者采用委托代理模型,以股东为风险中性、经理人为风险厌恶为基本假设,分析了限制性股票和股票期权两种股权激励形式的激励作用。结果显示,当限制性股票无偿赠送给经理人时,股票期权的激励作用大于股票的激励作用;为激励经理人采取股东希望的行动,股票期权对股东的经济成本低于限制性股票对股东的经济成本。这一结论为我国股权分置改革后上市公司选择股权激励方式提供了一定的理论借鉴。     

Product Safety Provision and Consumers' Information

Economic mechanisms related to the provision of product safety are explored, with particular attention paid to the structure of consumers' information. The case of perfect information, of experience goods (for which consumers detect product safety after consumption) and of credence goods (where consumers cannot link a disease to a particular product consumed in the past) are explored. Imperfect competition is assumed in the supply sector. In the case of both perfect information and experience goods, market equilibrium is characterised by a less-than-socially optimal provision of safety, when the safety effort is costly. With credence goods, imperfect information leads to the absence of safety effort and to a market closure. Different types of public regulation aiming at increasing consumer protection and circumventing market failures are explored. Particular attention is paid to minimum safety standards, labels and liability enforcement. The relative efficiency of these instruments depends on the information structure. In the cases of perfect information and experience goods, a minimum safety standard can be an efficient instrument. Regulation is necessary but not sufficient to avoid market failure in the case of credence goods.     

Computing equilibria with increasing returns

This paper shows how standard algorithms for solving economic general equilibrium models may be modified so as to solve models in which some or all industries have increasing returns to scale. The modification requires that some quantities as well as prices be quoted by the algorithmic auctioneer. It is applicable to a wide range of models in which firms pricing behavior follows simple rules. As an illustration of the technique a small general equilibrium model with increasing returns is presented and solved numerically.     

论我国上市公司董事会治理结构存在的问题与对策

我国上市公司董事会治理在董事会机构、董事会会议、独立董事、董事会外部制约机制等方面都存在一定问题.解决的对策是:增强董事会的独立性,改变大股东完全控制董事会的局面;加强独立董事制度建设,营造独立董事充分行权的环境;加强对董事的违规处罚力度,强化董事的诚信意识;建立科学合理的董事会考评机制.对于董事会的考核可以从两方面去进行:一方面是对董事会的整体考评,另一方面是对董事个人的考核.我国可以借鉴美国的考核评估方法,由非投资相关者专门针对董事会进行考核评估.     

Strategic Delegation and the Shape of Market Competition

What shape can we expect market competition to exhibit? This question is addressed in the present paper. Firms are allowed to choose whether to act as quantity or price setters, whether to move early or delay as long as possible at the market stage, and whether to be entrepreneurial or managerial. Moreover, firms can endogenously determine the sequence of such decisions. It is shown that in correspondence of the (unique) subgame perfect equilibrium of the game, all firms first decide to delay, then to act as Cournot competitors, and finally stockholders decide to delegate control to managers. Hence, sequential play between either managerial or entrepreneurial firms, as well as simultaneous play between entrepreneurial firms, are ruled out.     

A Keynesian Dynamic Stochastic Disequilibrium model for business cycle analysis

A Dynamic Stochastic Disequilibrium model is proposed for business cycle analysis. The core innovation and fundamental deviation from the corresponding full-employment Dynamic Stochastic General Equilibrium model is the assumption that the nominal wage is a policy variable with no tendency to clear the labor market. As a consequence, disequilibrium unemployment arises which crucially alters the transmission of macroeconomic shocks. Solving the puzzle of low fiscal multipliers in conventional general equilibrium models, the effects of spending shocks become considerably more pronounced in the disequilibrium model because idle labor can be quickly utilized to accommodate aggregate demand without requiring households to increase their supply. In contrast to the standard model, technology and labor supply shocks are partly absorbed by unemployment and, hence, only moderately expansionary. Despite its simplicity and unlike the corresponding general equilibrium model, the disequilibrium model is able to generate shock responses which are broadly in line with empirical evidence.