Cost Manipulation Games in Oligopoly, With Costs of Manipulating

We analyze a class of two-stage games where rival firms incur real resource costs in manipulating their marginal costs, so as to influence the outcome of the game they want to play in stage two. Marginal costs may be manipulated by various means, such as redistribution of productive assets, choice of location, or creation of an internal input market. A general formulation of the game is provided, and several applications are analyzed. We show that the optimal allocation of resources within an oligopoly can be asymmetric, even for ex-ante symmetric firms. This is an additional explanation of heterogeneity in oligopoly.     

Strategic Manipulation in Voting Games When Lotteries and Ties Are Permitted

A Gibbard-Satterthwaite type theorem is established for random decision rules and rules that permit ties. The rules use full information on how individuals rank lotteries and sets of outcomes. The theorem allows restrictions on the domain of rankings. Journal of Economic Literature Classification Numbers: D7, C7.     

Mindreading and Manipulation in an Ecology of Prisoner’s Dilemma Games: Laboratory Experiments

Synopsis Humans have a rational reason to seek out and selectively play Prisoner’s Dilemma games with others who (for whatever reason) will play cooperatively, while avoiding those who will defect. It follows that they also have reason to try and persuade others that they will personally cooperate if a game is joined (using the term from Evolutionary Psychology, to ‘manipulate’ others’ beliefs) and, thus, to penetrate to the truth underlying such efforts (to ‘mindread’ others intentions). We develop an economic model of mindreading and manipulation that can govern exchange relationships in natural circumstances, and report laboratory data showing that, absent constraining institutions that make play with cooperators likely, intending defectors are more likely to be chosen as partners than are intending cooperators. Intending defectors’ efforts at manipulation appear to be more successful than their potential victims’ efforts at mindreading. The findings suggest the nature of the problem that must be addressed for would-be traders in the absence of well-enforced rules governing contracts, and we discuss the patterns of behavior that are likely responses in such circumstances.     

The Promises and Problems of Games and Simulation

Many educators see the wave of the future in computer games and simulation. Lumsden gives an appreciation of the kind of games and simulations available and illustrates with specific detail how powerfully instructive some of these can be. He also makes a plea for scientific evaluation.     

Marriage Settlements

French couples may choose between two types of marriage settlements governing asset ownership after a divorce or inheritance: common property or separate property. A cooperative model considers the marriage contract as a means of providing for widowhood of the less endowed spouse. A second model addresses the probability of divorce and the production of a marriage good. The common property contract then becomes a means of inducing the wife to invest in the marriage good. Choice of contract, labor supply and fertility are simultaneous. Empirically we find that characteristics of the spouses such as relative age or differences in endowments influence the choice. So do the expected number of children and the wife's labor supply decision. This last decision is also shown to be influenced by the chosen settlement, while fertility is not.
JEL classification : J 12; J 4; K 12     

Information Manipulation in Election Campaigns

We provide a game‐theoretical model of manipulative election campaigns with two political candidates and a Bayesian voter. The latter is uncertain about how good the candidates are. Candidates take unobservable, costly actions to manipulate voter's opinion about their positions. We show that if the candidates differ in campaigning efficiency, and the voter receives the biased campaign messages with some noise, then the cost‐efficient candidate can win the election with higher probability than her opponent even when she is ex‐post an inferior choice for the voter. Our paper offers a novel informational justification for imposing limits on campaign spending and encouraging diversity in the supply of political information.     

“三农”问题与利益集团博弈

目前,我国存在着不同的利益集团,在国家决策过程中,进行着激烈博弈。“三农”问题的形成,则在于农民作为一个利益集团,无法与其他利益集团展开平等博弈。文章首先分析了利益集团的形成背景及其划分;其次,提出了农民与其他利益集团博弈中决策均衡点的形成依据;最后,提出了决策均衡点的实现机制。     

Common Pool Games are Convex Games

For the class of cooperative common pool games the paper focuses on the question of how, during the preplay negotiation process, the ability of coalitions to enforce their claims imposes externalities on the opposition by having an impact on the jointly produced resource. One of our main results is that common pool games are clear games. Based on this result we are able to derive sufficient conditions for the convexity of the characteristic function, which establishes the second main result in the paper, namely that cooperative common pool games are characterized by increasing returns with respect to the coalition size.     

股票市场操纵行为的微观机理分析

本文通过对操纵股票市场交易价格的行为进行理论实证分析,剖析这种现象发生的原因、条件和本质,分析操纵市场行为对社会效率的影响,提出了规范股票投资行为、提升市场投资价值的建议.     

论我国的无效婚姻制度

新中国建立后1950年的婚姻法与1980年的婚姻法对结婚、离婚从实体要件到程序要件均予以了具体规定，但均未明文规定无效婚姻制度。1963年最高人民法院的司法解释首次提到婚姻无效的问题，指出应“宣布重婚关系无效”。在司法实践中，由于对违法婚姻的效力问题缺乏明确的法律依据，法院一般将属于无效婚姻的诉讼按离婚案件处理。     

会计操纵识别

笔者研究了近年来国外会计操纵的一些常用手法和识别技巧,以期对目前我国规范财务和识别会计操纵有所借鉴。     

博弈论的新发展:行为博弈论

标准博弈论在"经济理性"假设下分析博弈参与者如何在追求各自最优目标的同时实现均衡。但是,由于现实行为人是"有限理性"的,标准博弈论对实践的解释和指导受到限制。为了延伸博弈论对现实活动的解释,行为博弈论将实验经济学与标准博弈论相融合,在博弈实验的基础上,考察和解释标准理论推断与实验结果之间的差异,引入行为因素改进标准博弈论的基本假定,重构博弈分析模型,以求达到准确解读有限理性的行为人在现实约束中如何行动的目的。     

Manipulation through political endorsements

We study elections with three candidates under plurality voting. A candidate is a Condorcet loser if the majority of the voters place that candidate at the bottom of their preference rankings. We first show that a Condorcet loser might win the election in a three-way race. Next we introduce to the model an endorser who has private information about the true probability distribution of the preferences of the voters. Observable endorsements facilitate coordination among voters who may otherwise split their votes and lead to the victory of the Condorcet loser. When the endorser has an ideological bias towards one of the candidates, the coordination impact of endorsements remains unaltered, moreover the endorser successfully manipulates the outcome of the election in favor of his bias, even if his ideological bias is known by the voters. The results are true for any endorsement cost and any magnitude of bias as long as the electorate is large enough.     

Action-Graph Games

Representing and reasoning with games becomes difficult once they involve large numbers of actions and players, because the space requirement for utility functions can grow unmanageably. Action-Graph Games (AGGs) are a fully-expressive game representation that can compactly express utility functions with structure such as context-specific independence, anonymity, and additivity. We show that AGGs can be used to compactly represent all games that are compact when represented as graphical games, symmetric games, anonymous games, congestion games, and polymatrix games, as well as games that require exponential space under all of these existing representations. We give a polynomial-time algorithm for computing a player's expected utility under an arbitrary mixed-strategy profile, and show how to use this algorithm to achieve exponential speedups of existing methods for computing sample Nash equilibria. We present results of experiments showing that using AGGs leads to a dramatic increase in the size of games accessible to computational analysis.²     

Games of Status

A status game is a cooperative game in which the outcomes are rank orderings of the players. They are a good model for certain situations in which players care about how their "status" compares with that of other players.
We present several formal models within this class. Included are authoritarian status games (where coalitions may assign positions in the rank ordering to nonmembers) and oligarchic status games (where they are unableto do so). We consider the issues of a value concept for authoritarian games and that of core existence for oligarchic games. We then add a transferable resource to the models, obtaining "games of wealth and status."
Finally, we consider an interesting variant, called a "secession game," where coalitions have the right to secede from the grand coalition and form their own smaller "subsocieties," each with its own hierarchy.     

Ambiguous Games

This paper introduces ambiguous games, a modification of the normal form that allows the presence of vagueness in players' beliefs over the opponents' choice of strategies. An appropriate notion of equilibrium is presented, and a general existence result is proved. Journal of Economic Literature Classification Numbers: C72, D81.     

Knowledge Games

The subject of epistemic logic is firmly entrenched in game theory, including the analysis of common knowledge and of public announcements, such as in 'hat problems'. How to analyse communications to sub groups of the public, and the effects of such common knowledge of a subgroup on the information state of a larger group, has only recently come into fruition. Knowledge games are introduced to provide a comfortably concrete vehicle for the study of such interactions. This paper introduces the concepts of knowledge game, deal of cards, knowledge game state, game action, and action execution. A deal of cards is a function from cards to players. A knowledge game state is represented by a pointed multiagent S5 model on the set of card deals where all players hold the same number of cards as in the actual deal. A game action combines a question with an answer, and is represented by a pointed multiagent S5 frame on the set of possible answers. The execution of a game action in a knowledge game state corresponds to the computation of a pointed multiagent S5 model that is a restriction of the direct product of the corresponding action frame and game model.