Coalition Formation with Binding Agreements

We study coalition formation in "real time", a situation in which coalition formation is intertwined with the ongoing receipt of pay-offs. Agreements are assumed to be permanently binding: They can only be altered with the full consent of existing signatories. For characteristic function games we prove that equilibrium processes—whether or not these are history dependent—must converge to efficient absorbing states. For three-player games with externalities each player has enough veto power that a general efficiency result can be established. However, there exist four-player games in which all Markov equilibria are inefficient from every initial condition, despite the ability to write permanently binding agreements.     

Coalition Formation and Potential Games

In this paper we study the formation of coalition structures in situations described by a cooperative game. Players choose independently which coalition they want to join. The payoffs to the players are determined by an allocation rule on the underlying game and the coalition structure that results from the strategies of the players according to some formation rule. We study two well-known coalition structure formation rules and show that for both formation rules there exists a unique component-efficient allocation rule that results in a potential game. Journal of Economic Literature Classification Numbers: C71, C72.     

A Theory of Gradual Coalition Formation

We study noncooperative multilateral bargaining games, based on underlying TU games, in which coalitions can renegotiate their agreements. We distinguish between models in which players continue to bargain after implementing agreements (reversible actions) and models in which players who implement agreements must leave the game (irreversible actions). We show that renegotiation always results in formation of the grand coalition if actions are reversible, but that the process may otherwise end with smaller coalitions. On the other hand, we show that the grand coalition cannot form in one step if the core of the game is empty, irrespective of the reversibility of actions.     

Coalition and Party Formation in a Legislative Voting Game

We examine a legislative voting game where decisions are to be made over both ideological and distributive dimensions. In equilibrium legislators prefer to make proposals for the two dimensions together, despite having preferences that are separable over the two dimensions. The equilibria exhibit interaction between the ideological and distributive dimensions, and the set of legislators who approve winning proposals does not always consist of ideologically adjacent legislators. There is more than one ideological decision that has a positive probability of being proposed and approved. We show that legislators can gain from forming political parties, and consider examples where predictions can be made about the composition of parties. Journal of Economic Literature Classification Numbers: D72, C71, C78.     

A New Bargaining Set of an N-Person Game and Endogenous Coalition Formation

The two most fundamental questions in cooperative game theory are: When a game is played, what coalitions will be formed and what payoff vectors will be chosen? Few solution concepts or theories in the current literature provide satisfactory answers to both questions; answers are especially lacking for the first one. In this paper we introduce a new bargaining set, which is the first solution concept in cooperative game theory that provides answers to both fundamental questions endogenously. Journal of Economic Literature Classification Number: C71.     

Party Formation and Policy Outcomes under Different Electoral Systems

I introduce a model of representative democracy with strategic parties, strategic candidates, strategic voters and multiple districts. If policy preferences are similar across districts and not too concentrated within districts, then the number of effective parties is larger under proportional representation (PR) than under plurality, and both electoral systems determine the median voter's preferred policy. However, for more asymmetric distributions of preferences the Duvergerian predictions can be reversed , and the policy outcome with PR is more moderate than the one with plurality. Sincere voting induces more party formation, and strategic voting can be observed more often under PR.     

Stable Coalition Structures with Externalities

This paper argues that the sign of external effects of coalition formation provides a useful organizing principle in examining economic coalitions. In many interesting economic games, coalition formation creates eithernegativeexternalities orpositiveexternalities for nonmembers. Examples of negative externalities are research coalitions and customs unions. Examples of positive externalities include output cartels and public goods coalitions. I characterize and compare stable coalition structures under the following three rules of coalition formation: the Open Membership game of Yi and Shin (1995), the Coalition Unanimity game of Bloch (1996), and the Equilibrium Binding Agreements of Ray and Vohra (1994).Journal of Economic LiteratureClassification Numbers: C72, C71.     

Coalition governments in a model of parliamentary democracy

We analyse a model of coalition government in a parliamentary democracy where parties care both for ideology and perks from office, and examine how the magnitude of this tradeoff affects the nature of coalitions that form. It is shown that equilibrium coalitions can be minimal winning, minority or surplus and they may be ideologically disconnected. The types of coalitions that emerge depend upon the relative importance of rents from office and the distribution of party ideologies. Further, there is a non-monotonic relationship between ideological connectedness of coalitions and rents from office.     

A Theory of Endogenous Coalition Structures

Consider an environment with widespread externalities, and suppose that binding agreements can be written. We study coalition formation in such a setting. Our analysis proceeds by defining on a partition function an extensive-form bargaining game. We establish the existence of a stationary subgame perfect equilibrium for such a game. Our main results are concerned with the characterization of equilibriumcoalition structures. We develop an algorithm that generates (under certain conditions) an equilibrium coalition structure. Our characterization results are especially sharp forsymmetricpartition functions. In particular, we provide a uniqueness theorem and apply our results to a Cournot oligopoly.Journal of Economic LiteratureClassification Numbers: C71, C72, C78, D62.     

Coalition formation as a dynamic process

We study coalition formation as an ongoing, dynamic process, with payoffs generated as coalitions form, disintegrate, or regroup. A process of coalition formation (PCF) is an equilibrium if a coalitional move to some other state can be “justified” by the expectation of higher future value, compared to inaction. This future value, in turn, is endogenous: it depends on coalitional movements at each node. We study existence of equilibrium PCFs. We connect deterministic equilibrium PCFs with unique absorbing state to the core, and equilibrium PCFs with multiple absorbing states to the largest consistent set. In addition, we study cyclical as well as stochastic equilibrium PCFs.     

部门-地方-经济实体非正式同盟--地方腐败的组织社会学分析

当前地方政府成为腐败的多发地带，而地方腐败越来越呈现出集团化、隐秘化的特点，这种集团化和隐秘化腐败用组织社会学方法来分析，可以称之为“部门—地方—经济实体非正式同盟”，正是中央部门、地方政府和经济实体三方核心人物之间出现了非正式的内部联盟，地方腐败问题才不断出现，并变得难以发现和查处。这一同盟具有不同于一般腐败的特殊性和严重性。     

The Stability of Hedonic Coalition Structures

We consider the partitioning of a society into coalitions in purely hedonic settings, i.e., where each player's payoff is completely determined by the identity of other members of her coalition. We first discuss how hedonic and nonhedonic settings differ and some sufficient conditions for the existence of core stable coalition partitions in hedonic settings. We then focus on a weaker stability condition: individual stability, where no player can benefit from moving to another coalition while not hurting the members of that new coalition. We show that if coalitions can be ordered according to some characteristic over which players have single-peaked preferences, or where players have symmetric and additively separable preferences, then there exists an individually stable coalition partition. Examples show that without these conditions, individually stable coalition partitions may not exist. We also discuss some other stability concepts, and the incompatibility of stability with other normative properties. Journal of Economic Literature Classification Numbers: C71, A14, D20.     

Coalition Stability in Public Goods Provision: Testing an Optimal Allocation Rule

We test the canonical model of international environmental agreements (IEAs) in a laboratory setting with asymmetric agents. IEA participation represents coalition formation and public good provision where there are gains to cooperation, but an incentive to free-ride. We test four competing methods of dividing the coalition’s worth: a recently proposed optimal rule which accounts for subjects’ payoffs as a single free-rider, the Shapley value, the Nash bargaining solution, and an equal split. Each treatment generates the theoretically predicted coalition size more often than not. The shares of the potential gains to cooperation achieved by each rule are: 51, 36, 40 and 13%, respectively. These results highlight the importance of using an optimal rule to improve IEAs, and more broadly for voluntary public good provision.     

A Risk‐Dominant Allocation: Maximizing Coalition Stability

This paper presents a rule to allocate a coalition’s worth for superadditive games with positive externalities. The allocation rule awards each member their outside payoff, plus an equal share of the surplus. The resulting allocation maximizes coalition stability. Stable coalitions are Strong Nash equilibria since no subset of members has an incentive to leave. Similarly, no subset of non‐members has an incentive to join a stable coalition if the game is concave in this region. The allocation is risk‐dominant. All stable coalitions are robust to the maximum probability of 50% that players’ deviate from their individual best‐responses. The paper compares the allocation to the Shapley value and the Nash bargaining solution, and illustrates why these traditional rules result in small coalitions when applied to issues such as international environmental agreements.     

整体厨柜的绿色设计研究

以绿色设计的概念与原则为启示,结合整体厨柜产品的特点和功能要求,分析了整体厨柜产品绿色设计方法,论述了整体厨柜产品在材料选择、结构设计、工艺安排、回收再利用及节能设计等方面的绿色设计实现方法,为从根本上解决整体厨柜产品质量安全问题提供依据,同时丰富整体厨柜产品的设计理论与方法.     

An Algorithm for Stable and Equitable Coalition Structures with Public Goods

We study the formation of coalitions that provide public goods to members. Individuals are linked on a tree graph and those with similar preferences are connected on the tree. We present a well‐defined solution that selects envy‐free allocations from the core.     

Coalition Emergency Response System, City Security and City Sustainable Development

The relations among the establishment of Coalition Emergency Response System （CERS）, city security and city sustainable development are analyzed in the article. According to the relation analysis, it is concluded that cities should build up their CERS to deal with the thread of damage in China. The recommendations about the establishment of the system are also provided.     

从价值链理论看财务公司的战略联盟

从1987年第一家财务公司成立,到今天我国共有财务公司78家,总资产超过3460亿元,所属企业集团分布于国民经济数十个部门。由于我国的财务公司普遍规模较小,管理水平低,金融创新能力弱,在加入WTO后,随着我国金融业的逐渐开放,财务公司面临着严峻的挑战。为在激烈的竞争环境中发展壮大,我国财务公司可通过建立战略联盟,实现价值链各环节     

Group Formation in Risk-Sharing Arrangements

We study informal insurance within communities, explicitly recognizing the possibility that subgroups of individuals may destabilize insurance arrangements among the larger group. We therefore consider self-enforcing risk-sharing agreements that are robust not only to single-person deviations but also to potential deviations by subgroups. However, such deviations must be credible, in the sense that the subgroup must pass exactly the same test that we apply to the entire group; it must itself employ some self-enforcing risk-sharing agreement. We observe that the stability of subgroups is inimical to the stability of the group as a whole. Two surprising consequences of this analysis are that stable groups have (uniformly) bounded size, a result in sharp contrast to the individual-deviation problem, and that the degree of risk-sharing in a community is generally non-monotonic in the level of uncertainty or need for insurance in the community.