sequential formation of coalitions in games with externalities and fixed payoff division this paper analyzes a sequential game of coalition formation when the division of the coalitional surplus is fixed and the payoffs are defined relative to the whole coalition structure gains from cooperation are represented by a valuation which maps coalition structures into payoff vectors i show that any core stable coalition structure can be attained as a stationary perfect equilibrium of the game if stationary perfect equilibria may fail to exist in general games a simple condition is provided under which they exist in symmetric games furthermore symmetric stationary perfect equilibria of symmetric games generate a coalition structure which is generically unique up to a permutation of the players a general method for the characterization of equilibria in symmetric games is proposed and applied to the formation of cartels in oligopolies and coalitions in symmetric majority games journal of economic literatureclassification numbers c78 c71 1996 academic press inc

guarding the guardians good government requires some restraints on the powerful but how can those be impose if there is no one above them this paper studies the equilibrium allocation of power and resources established by self interested incumbents under the threat of rebellions from inside and outside the group in power commitment to uphold individuals rights can only be achieved if power is not as concentrated as incumbents would like it to be ex post power sharing endogenously enables incumbents to commit to otherwise time inconsistent laws by ensuring more people receive rents under the status quo and thus want to defend it

dynamic processes of social and economic interactions on the persistence of inefficiencies an economy with a finite number of agents and a finite number of states is considered an exogenous institutional rule prescribes which moves from one state to another are feasible to each coalition at each time an agent is called to act with some exogenous probability and he chooses a coalition a feasible new state to move the economy to and side payments between the agents in the coalition the setup can be applied to various dynamic processes of social and economic interactions such as legislative bargaining coalition formation or exchange economies whenever agents are unable to write long term contracts but are otherwise unconstrained both in their ability to write arbitrary spot contracts and in their ability to collude there can be long run inefficiencies with cycles or inefficient steady states however when agents are sufficiently patient the initial state from which the process starts plays no role in the long run moreover when there exists an efficient state that is free of negat

coalition and party formation in a legislative voting game we examine a legislative voting game where decisions are being made over both ideological and distributive dimensions and legislators preferences are separable over the two dimensions in equilibrium legislators prefer to make proposals for the two dimensions together rather than offering sequential proposals on the two dimensions separately the equilibria exhibit interaction between the ideological and distributive dimensions and in any equilibrium there is a positive probability that a proposal is made and approved which excludes the median legislator as defined over the ideological dimension in contrast with a game where no distributive decision is being made moreover in any stationary equilibrium 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 we discuss the impact of political parties on the outcome

a theory of endogenous coalition structures consider an environment with widespread externalities and suppose that bind ing 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 equilib rium coalition structures we develop an algorithm that generates under certain conditions an equilibrium coalition structure our characterization results are especially sharp for symmetric partition functions in particular we provide a uniqueness theorem and apply our results to a cournot oligopoly journal of economic literature classification numbers c71 c72 c78 d62 q 1999 academic press

farsighted coalitional stability abstract i define the largest consistent set a solution concept which applies to situations in which coalitions freely form but cannot make binding contracts act publicly and are fully farsighted in that a coalition considers the possibility that once it acts another coalition might react a third coalition might in turn react and so on without limit i establish weak nonemptiness conditions and apply it to strategic and coalitional form games and majority rule voting i argue that it improves on the von neumann morgenstern stable set as it is usually defined but is consistent with a generalization of the stable set as in the theory of social situations journal of economic literature classification numbers c70 c71

bargaining in legislatures bargaining in legislatures is conducted according to formal rules specifying who may make proposals and how they will be decided legislative outcomes depend on those rules and on the structure of the legislature although the social choice literature provides theories about voting equilibria it does not endogenize the formation of the agenda on which the voting is based and rarely takes into account the institutional structure found in legislatures in our theory members of the legislature act noncooperatively in choosing strategies to serve their own districts explicitly taking into account the strategies members adopt in response to the sequential nature of proposal making and voting the model permits the characterization of a legislative equilibrium reflecting the structure of the legislature and also allows consideration of the choice of elements of that structure in a context in which the standard institution free model of social choice theory yields no equilibrium

state regulation and hospital costs the effects of various regulations on hospital costs are estimated using a two decade long panel data set which spans the initiation and in some instances the repeal of various forms of hospital regulation the long panel fosters two improvements over previous research first as state hospital cost levels may affect states incentive to regulate fixed effect estimators alleviate omitted variable bias derived from the states regulatory discretion second the long panel permits the estimation of many different regulatory program effects but also facilitates the analysis of potential regulatory program interaction the empirical results suggest that previous studies have exaggerated regulatory cost savings although some interaction effects are indicated hospital costs appear unresponsive to most regulatory programs copyright 1995 by mit press

allocative inefficiency in the production of hospital services researchers have offered numerous theoretical models of hospital behavior that suggest inefficiency in the provision of hospital services explanations of inefficiency are tied to the organization and regulation of the industry principal agent problems and the dominance of third party reimbursement eakin and kniesner 3 use a non minimum cost function to obtain estimates of allocative inefficiency for 331 u s short term hospitals in this paper i fill a void in the hospital cost literature by investigating variations in allocative inefficiency in the short term hospital industry this is done by regressing the allocative inefficiency estimates from eakin and kniesner against hospital characteristics predicted by theory as determinants of inefficiency i define allocative inefficiency at the firm level but from a social point of view specifically allocative inefficiency results from the technically efficient employment of inputs in a combination which is not cost minimizing a hospital may choose a non cost minimizing set of inputs if it evaluates the shadow prices of inputs as being different from the actual prices a shadow price is the hospital s internal perception of the unit cost of an input this perception may differ from the actual input price if for example the input enters directly into the hospital s objective function the hospital is assumed to minimize shadow cost by equating the marginal rate of technical substitution and the ratio of input shadow prices thus it is the shadow cost function that is dual to the underlying technology the hospital is modelled as a multiproduct firm a modified translog cost function is used to develop a system of observed cost and share equations which is estimated via seemingly unrelated non linear regressions empirical results indicate that overcapitalization and underemployment of physicians increase short term hospital costs by about 5 percent hospital care expenditures are about 4 5 percent of the gross national product which is almost three times the percentage in 1960 thus 5 percent represents a large amount in actual dollars further investigation identifies hospital size market share regulations and geographic region as the hospital characteristics related to the measure of allocative inefficiency this paper is organized as follows in section ii i develop the empirical model based on a non minimum cost function the traditional minimum cost function is a special case and thus

equilibrium binding agreements abstract we study equilibrium binding agreements the coalition structures that form under such agreements and the efficiency of the outcomes that result we analyze such agreements in a context where the payoff to each player depends on the actions of all other players thus a game in strategic form is a natural starting point unlike the device of a characteristic function explicit attention is paid to the behavior of the complementary set of players when a coalition blocks a proposed agreement a solution concept and its applications are discussed journal of economic literature classification numbers c70 c71

bose einstein dynamics and adaptive contracting in the motion picture industry audiences discover what films they like and spread the word information feedback produces bose einstein dynamics in the motion picture box office revenue distribution information cascades generate box office hits and flops the revenue distribution evolves recursively over the run as a mixture of the opening and a stochastic competition among films the motion picture run is decentralized adaptive and self organizing semistationary admission prices local information and contingency rich contracts match the film rental price and the supply of theatrical engagements to demand copyright 1996 by royal economic society

transferring ownership of public housing to existing tenants a market design approach this paper explores a housing market with an existing tenant in each house and where the existing tenants initially rent their houses the idea is to identify equilibrium prices for the housing market given the prerequisite that a tenant can buy any house on the housing market including the one that he is currently possessing or continue renting the house he is currently occupying the main contribution is the identification of an individually rational equilibrium selecting and group non manipulable price mechanism in a restricted preference domain that contains almost all preference profiles in this restricted domain the identified mechanism is the minimum price equilibrium selecting mechanism that transfers the maximum number of ownerships to the existing tenants we also relate the theoretical model and the main findings to the u k housing act 1980 whose main objective is to transfer ownerships of houses to existing tenants

quality signals in information cascades and the dynamics of the distribution of motion picture box office revenues abstract the movies are an ideal testing ground for information cascade models one can observe the dynamics of box office revenues from the opening to the end of the run to study the possibility that information cascades occur in the movies one has to incorporate the fact that agents can observe box office revenues as reported on the evening news and communicate word of mouth information about the quality of the movies they have seen one must consider many movies rather than the mere two choices assumed in information cascade models we develop an agent based model of information cascades with these extensions our objective is to see if the conclusions of information cascade models hold with these extensions they do not and to see if the agent based model can capture the features of the motion picture box office revenues it does

a model of agreements in strategic form games abstract because in a strategic form game all the possibilities of communication available to the players must be explicitly listed in the strategy spaces coalitions and coalitional behaviour are not very often taken into account in noncooperative games however it may be desirable especially in applications to separate the basic strategic features of a situation from those strategic features added as a consequence of the possibility of coalitional behaviour we define an equilibrium for the bargaining procedure called by greenberg the theory of solid situations an alternative game theoretic approach cambridge university press cambridge uk 1990 coalitional contingent threat situation we argue that the crucial problem of expectations on the counterdeviations following a deviation can be addressed by defining coalitional strategies and studying the equilibrium of the extended game journal of economic literatureclassification numbers c70 c71

collective rent dissipation the theory of rent seeking was initiated by tullock 1967 1980 followed by krueger 1974 and posner 1975 and more recently extended in various directions by allard 1988 appelbaum and katz 1986a b c gradstein and nitzan 1989 hillman and katz 1984 1987 hillman and samet 1987 hillman and riley 1989 katz et al 1990 long and vousden 1987 ursprung 1990 and varian 1989 the purpose of this paper is to extend this theory by introducing the possibility of collective group rent seeking with voluntary individual decisions regarding their extent of participation in the collective rent seeking efforts

forecasting marketing mix responsiveness for new products abstract before a new product launch marketers need to infer how demand will respond to various levels of marketing mix variables to set an appropriate marketing plan a critical challenge in estimating marketing mix responsiveness from historical data is that the observed decisions were affected by private information possessed by managers about the heterogeneous effects of marketing mix variables on sales the authors refer to this as the slope endogeneity problem such endogeneity differs from the intercept endogeneity problem which has been widely acknowledged in the literature to correct for the slope endogeneity bias the authors develop a conceptually simple control function approach that is amenable to multiple endogenous variables and marketing mix carryover effects the method is applied to forecasting advertising responsiveness in the u s dvd market the results suggest that advertising responsiveness varies substantially across dvd titles and that estimated marketing mix elasticities w

market crashes and informational avalanches this paper analyses a security market with transaction costs and a sequential trading structure transaction costs may prevent many traders from revealing their private information if they trade in a sequential fashion due to the information aggregation failure hidden information gets accumulated in the market which may be revealed by a small trigger yielding a high volatility in the absence of an accompanying event the paper first characterizes the optimal trading strategy of the agent which constitute the unique equilibrium further properties of the price sequence are obtained using the concepts of informational cascade and informational avalanche the results are applied to the explanation of market crashes in particular the dynamics of market crashes are illustrated as evolving through the following four phases 1 boom 2 euphoria 3 trigger and 4 panic where the euphoria corresponds to the informational cascade and the panic corresponds to the informational avalanche

anarchy and its breakdown anarchy defined as a system in which participants can seize and defend resources without regulation from above is not chaos but rather a spontaneous order however anarchy is fragile and may dissolve either into formless amorphy or into a more organized system such as hierarchy under anarchy each contestant balances between productive exploitation of the current resource base and fighting to acquire or defend resources anarchy is sustainable only when there are strongly diminishing returns to fighting effort the decisiveness parameter is sufficiently low and incomes exceed the viability minimum these considerations explain many features of animal and human conflict

can empirical demand models assist in con comparative reviews a case study in florida certificate of need con programs for new hospital construction are intended to foster the best selection among competing hospital applications given demands for hospital care in the community yet the merits of con depend in part on the quality of the comparative review process this article examines a case study in florida to illustrate the utility of empirical evaluations using patient choice models i estimate such models to show how patients would respond to a change in hospital choices by simulating the welfare effects of the proposed hospitals i can further predict how prices of hospital care differ by applicant results suggest that empirical analysis using data on patient choice of hospitals may better inform the review process at the same time however it may not give a unique ranking without additional analysis of the fixed costs of proposed services in the context of existing marketwide capacity

a generalized model of rent seeking behavior in this paper i present a formal analysis of rent seeking games in which the players valuations for the prize are represented as vectors the players in this game are risk neutral and may not be indifferent to who wins the contestable rent if it is someone else both tullock s original rent seeking model and the public goods rent seeking model by katz et al turn out to be special cases of this more general model

resale markets and the assignment of property rights the consumption of an indivisible good causes identity dependent externalities to non consumers we analyse resale markets where the current owner designs the trading procedure but cannot commit to future actions we ask the following questions 1 doer the identity of the initial owner matter for the determination of the final consumer 2 is the outcome always efficient the major conclusion of our paper is that the irrelevance of the initial structure of property rights arises in resale processes even if there are transaction costs that hinder efficiency this result complements the coasian view where the irrelevance of the assignment of property rights is a consequence of efficiency

conflict and rent seeking success functions ratio vs difference models of relative success the rent seeking competitions studied by economists fall within a much broader category of conflict interactions that also includes military combats election campaigns industrial disputes lawsuits and sibling rivalries in the rent seeking literature each party s success pi which can be interpreted either as the probability of victory or as the proportion of the prize won has usually been taken to be a function of the ratio of the respective resource commitments alternatively however pi may instead be a function of the difference between the parties commitments to the contest the contest success function csf for the difference from is a logistic curve in which as is consistent with military experience increasing returns apply up to an inflection point at equal resource commitments a crucial flaw of the traditional ratio model is that neither onesided submission nor two sided peace between the parties can ever occur as a cournot equilibrium in contrast both of these outcomes are entirely consistent with a model in which success is a function of the difference between the parties resource commitments

do juntas lead to personal rule january 2009although almost half of the world s population lives under nondemocratic regimes thequestions of how policy decisions are made and how power changes hands in nondemocra cies have received relatively little attention in the political economy literature a popularview forcefully articulated by gordon tullock 1987 is that because there are no stronginstitutions ensuring consensus and regulating the election and succession of leaders non democratic regimes rapidly degenerate into personal rule where a single dictator dominatesevery aspect of decision making tullock writes empirically the junta characteristicallyshrinks to one man p 144 and continues to explain this as the result of dynamic in teractions among the members of the junta he suggests that there will typically be anaccumulation of power by one of the junta members if this upstart member succeeds hebecomes the sole ruler if he fails he is eliminated by the other members of the junta this process continues until one member is standing tullock thus concludes it can beseen that this process would tend over time to lead the junta into becoming just one manthrough the gradual exclusion of individuals who had failed in plotting or the success of anindividual who had not p 145 tullock s account like that of many others implicitly recognizes that politics in non democratic and weakly institutionalized societies should be conceptualized as one of thedynamic coalition formations there are no rules that ensure orderly transitions of powerand no checks against some members of the ruling coalition eliminating or sidelining others however formal models of dynamic coalition formation in nondemocratic societies have notbeen developed until recently in this paper we draw on our work on dynamic coalition formation daron acemoglu georgy egorov and konstantin sonin 2008a and investigate tullock s conjecture formally 1

endogenous formation of coalitions the formation of coalitions is a fundamental problem in game theory by a coalition is meant a group of players e g economic or political agents which decide to act together as one unit relative to the rest of the players this includes the instances of syndicates unions cartels blocks political parties parliamentary coalitions etc we would like to emphasize that forming a coalition does not eliminate the individual players as decision makers in all interactions with the other players coalition members act as one unit it may be useful to think of a representative agent taking their place 2 however this arrangement will continue only as long as each player finds it desirable to act this way further bargaining occurs among the members of each coalition on how to divide what they obtained together thus the existence of coalitions implies that the interactions among the players will be conducted on two levels first among the coalitions and second within each coalition most of the existing models in economics and game theory assume that the coalition structure is given exogenously instead we try here to obtain it as an endogenous outcome of our model namely we want to be able to predict which coalitions will in fact form in each given situation 3 our theory combines two kinds of game theoretic concepts value and stability the basic idea is first to evaluate the players prospects in the various coalition structures and then based on these values to find which ones are stable we will call this value coalition structure value or cs value for short the reason we are considering coalition structures i e partitions of the set of players into disjoint coalitions rather than just coalitions is that in general players may find it to their advantage to join forces in some situations and to act separately in others all depending on the way the other participants are organized this implies that both the value and the stability concepts should depend on the entire coalition structure the cs value we analyze in this paper was first developed by owen 7

power fluctuations and political economy we study constrained pareto e cient allocations in a dynamic production economy where the group that holds political power decides the allocation of resources for high discount factors the economy converges to a rst best allocation where labor supply decisions are not distorted for low discount factors distortions do not disappear and uctuate over time most importantly the set of sustainable rst best allocations is larger when there is less persistence in the identity of the party in power because this encourages political compromise this result contradicts the common presumption that there will be fewer distortions when there is a stable ruling group

on the formation of alliances in conflict and contests this paper examines the problem of the formation of alliances in conflict and more generally in contests with three players each player possesses an exogenous strategic endowment e g arms efforts rent seeking activity the outcome of contests including those between any alliances of players is governed by a contest success function csf in the three person one cake problem an alliance between two players against the third one will form if and only if the csf has an increasing returns characteristic when an alliance forms there is a tendency to be formed by the weaker players against the strongest player similar tendencies exist in other three person problems that i examine

a quantitative theory of political transitions we develop a quantitative theory of repeated political transitions driven by revolts and reforms in the model the beliefs of disenfranchised citizens play a key role in determining revolutionary pressure which in interaction with preemptive reforms determine regime dynamics we study the quantitative implications of the model by fitting it to data on the universe of political regimes existing between 1946 and 2010 the estimated model generates a process of political transitions that looks remarkably close to the data replicating the empirical shape of transition hazards the frequency of revolts relative to reforms the distribution of newly established regime types after revolts and reforms and the unconditional distribution over regime types

coalition formation in non democracies we study the formation of a ruling coalition in non democratic societies where institutions do not enable political commitments each individual is endowed with a level of political power the ruling coalition consists of a subset of the individuals in the society and decides the distribution of resources a ruling coalition needs to contain enough powerful members to win against any alternative coalition that may challenge it and it needs to be self enforcing in the sense that none of its subcoalitions should be able to secede and become the new ruling coalition we present both an axiomatic approach that captures these notions and determines a generically unique ruling coalition and the analysis of a dynamic game of coalition formation that encompasses these ideas we establish that the subgame perfect equilibria of the coalition formation game coincide with the set of ruling coalitions resulting from the axiomatic approach a key insight of our analysis is that a coalition is made self enforcing by the failure of its winning subcoalitions to be self enforcing this is most simply illustrated by the following example with majority rule two person coalitions are generically not self enforcing and consequently three person coalitions are self enforcing unless one player is disproportionately powerful we also characterize the structure of ruling coalitions for example we determine the conditions under which ruling coalitions are robust to small changes in the distribution of power and when they are fragile we also show that when the distribution of power across individuals is relatively equal and there is majoritarian voting only certain sizes of coalitions e g with majority rule coalitions of size 1 3 7 15 etc can be the ruling coalition copyright 2008 wiley blackwell

a general analysis of rent seeking games in this paper we reconsider the basic model of efficient rent seeking we stress the importance of the shape of the players reaction curve in order to understand the impact of the technology of rent seeking on the structure of the outcome of the game we give a complete characterization of the pure strategy equilibria moreover the possibility of preemption by a stakelberg leader is discussed according to the nature of the technology of rent seeking available to the agents

kleptocracy and divide and rule a model of personal rule many developing countries have suffered under the personal rule of kleptocrats who implement highly inefe cient economic policies expropriate the wealth of their citizens and use the proceeds for their own glorie cation or consumption we argue that the success of kleptocrats rests in part on their ability to use a divide and rule strategy made possible by the weakness of institutions in these societies members of society need to cooperate in order to depose a kleptocrat yet such cooperation may be defused by imposing punitive rates of taxation on any citizen who proposes such a move and redistributing the benee ts to those who need to agree to it thus the collective action problem can be intensie ed by threats which remain off the equilibrium path in equilibrium all are exploited and no one challenges the kleptocrat kleptocratic policies are more likely when foreign aid and rents from natural resources provide rulers with substantial resources to buy off opponents when opposition groups are shortsighted when the average productivity in the economy is low and when there is greater inequality between producer groups because more productive groups are more dife cult to buy off jel o12 h00

a noncooperative view of coalition formation and the core a noncooperative implementation of the core is provided for games with transferable utility the implementation obtained here is meant to reflect the standard motivation for the core as closely as possible in the model proposed time is continuous this idealized treatment of time is most amenable for capturing an essential feature of the core there is always time to reject a noncore proposal before it is consumated

profit variability in for profit and not for profit hospitals this paper proposes two tests of the hypothesis that not for profit hospitals nfps behave differently than for profit hospitals the profit variability test states that the profits of an nfp will be less variable over time than profits of a for profit hospital if the nfp maximizes utility subject to a profit constraint the second test examines whether nfp profits respond less to change in exogenous factors such as medicare reimbursement rates than profits of for profit hospitals both tests performed on panel data from 1983 to 1988 support the hypothesis that nfps behave differently than for profit hospitals

political economy in a changing world we provide a general framework for the analysis of institutional dynamics in an environment in which payoffs and political powers change stochastically assuming that economic and political institutions as well as individual types can be ordered and preferences and the distribution of political power satisfy natural single crossing increasing differences conditions we prove existence of a pure strategy markov voting equilibrium provide conditions for its uniqueness and present a number of comparative static results we then use this framework to study the dynamics of political rights and repression in the presence of threats from extremist groups and the dynamics of collective experimentation

dynamics and stability of constitutions coalitions and clubs a central feature of dynamic collective decision making is that the rules that govern the procedures for future decision making and the distribution of political power across players are determined by current decisions for example current constitutional change must take into account how the new constitution may pave the way for further changes in laws and regulations we develop a general framework for the analysis of this class of dynamic problems under relatively natural acyclicity assumptions we provide a complete characterization of dynamically stable states as functions of the initial state and determine conditions for their uniqueness we show how this framework can be applied in political economy coalition formation and the analysis of the dynamics of clubs the explicit characterization we provide highlights two intuitive features of dynamic collective decision making 1 a social arrangement is made stable by the instability of alternative arrangements that are preferred by sufficiently many members of the society 2 efficiency enhancing changes are often resisted because of further social changes that they will engender

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 agreements between players form the basis of much that game theory seeks to explain there are obviously many useful ways to categorize such agreements in multilateral negotiations that is with more than two participants it seems natural to distinguish between cases in which the coalition forms in one step and those in which the coalition grows to its eventual size by attracting new members thus recipients of marshall aid collectively agreed to american terms at the ceec in 1947 whereas a strict subset of these countries agreed to the schuman plan in 1950 with the other current members joining the eu over time similarly negotiations on climate change culminated in universal agreement at rio in 1992 whereas india and china only agreed to reduce cfc emissions in london in 1990 after other countries had signed up to the montreal protocol finally un security council resolution 242 urged that a multilateral conference be set up to establish a comprehensive settlement in the middle east whereas the process initiated by the oslo agreements and arguably camp david has consisted of a sequence of agreements between israel and its neighbours we will refer to cases in which the grand coalition forms in one step as involving immediate coalition formation or icf for short and cases in which a coalition grows as involving gradual coalition formation

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

stable coalition structures with a unidimensional set of alternatives abstract we identify a class of economic and political environments that admit an s equilibrium where both free mobility and free entry are allowed we further study the relationship between the set of s equilibria and the sets of strong and coalition proof nash equilibria in the noncooperative coalition formation game which is closely related to the one originally studied by j von neumann and o morgenstern theory of games and economic behaviour princeton univ press princeton nj 1944 we also show that the set of s equilibria induces a proper subset of the coalition structure core of the corresponding characteristic function form journal of economic literature classification numbers c71 c72

dynamic collective choice with endogenous status quo we analyze a bargaining situation in which preferences evolve over time and the previous agreement becomes the next status quo the endogeneity of the status quo exacerbates the players conflict of interest players disagree more often than under exogenous status quo this leads to inefficiencies and status quo inertia under certain conditions the negotiations can come to a complete gridlock players never reach an agreement gridlock can occur between players with arbitrarily similar preferences provided they are sufficiently patient in legislative settings our model predicts polarization and explains why legislators may fail to react promptly to economic shocks

order independent equilibria we study a noncooperative game of coalition formation based on an underlying game in coalitional form we introduce order independent equilibria oie a strategy profile is an oie if for any specification of first movers in the sequential game it remains an equilibrium and leads to the same payoff our results are 1 payoffs in oie that use pure stationary strategies must be in the core of the underlying game in coalitional form 2 if the underlying game has the property that all its subgames have nonempty cores then for each payoff vector there exists an oie with the same payoff journal of economic literature classification numbers c70 c71 c72 c78