international environmental agreements for river sharing problems we study partial coalition formation and the strategic timing of membership of an iea for environmental issues in the coalitional bargaining game cbg of gomes econometrica 73 1329 1350 2005 we apply the cbg to a specific river sharing problem with two symmetric upstream agents each at a tributary and one downstream agent located at the junction of tributaries we identify five regions in the parameter space of a discount factor and a productivity parameter for water in one region the grand coalition always forms immediately in two other regions immediate formation of the grand coalition and gradual coalition formation both occur with positive probability in another two regions only gradual coalition formation occurs in one of these latter regions a region with discount factors close to one both upstream agents form a monopoly with positive probability formation of the monopoly persists in the limit as the discount factor goes to one

existence of stationary bargaining equilibria abstract this paper addresses the question of existence of stationary markov perfect equilibria in a class of dynamic games that includes many known bargaining models and models of coalition formation general sufficient conditions for existence of equilibria are currently lacking in a number of interesting environments e g models with non convexities consumption lower bounds or an evolving state variable the main result establishes existence of equilibrium under compactness and continuity conditions without the structure of convexity or strict comprehensiveness used in the extant literature the proof requires a precise selection of voting equilibria following different proposals using a generalization of fatou s lemma

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

a non cooperative bargaining theory with incomplete information verifiable types abstract we consider a non cooperative sequential bargaining game with incomplete information where two players negotiate for mechanisms with ex post verifiable types at the interim stage we prove the existence of a stationary sequential equilibrium of the bargaining game where the ex post nash bargaining solution with no delay is asymptotically implemented with probability one further the ex post nash bargaining solution is a unique outcome of a stationary equilibrium under the property of independence of irrelevant types iit whereby the response of every type of a player is independent of allocations proposed to his other types and under a self selection property of their belief

determinants of interest group formation it is widely recognized that interest groups affect both microeconomic and macroeconomic outcomes however few researchers have attempted to discern empirically the factors that contribute to interest group activity this paper provides a test of several theories of group formation in a panel setting a nation s stability socioeconomic development political system size and diversity all appear to contribute to interest group formation as predicted by theory

coalition formation and bargaining protocols a review of the literature this paper offers a review of the vast literature regarding bargaining and coalition formation this topic has been generally described as the attempt to provide strategic foundations to cooperative solution concepts it can therefore be seen as the linking ring between the non cooperative and the cooperative game theoretic approach to coalition formation its central role in economic theory and its relatively long history that goes back to the nash program have fostered a large academic production including surveys nonetheless this paper will focus on an aspect that is often neglected in the dedicated surveys the specificities of the bargaining protocols leading to different outcomes although generally downgraded to the rank of details the differences in bargaining protocols even when minor can cause significant changes in fundamental aspects such as the possibility to reach full cooperation the distribution of final pay offs and the time taken to reach an agreement focused on externalities free games therefore on bargaining protocols sustaining solution concepts for cooperative games in characteristic function form the paper aims at providing a brief but exhaustive review of the topic that could result in a very useful tool for any researcher approaching the subject of coalitional bargaining

uniqueness of stationary equilibrium payoffs in coalitional bargaining we study a model of sequential bargaining in which in each period before an agreement is reached the proposer s identity is randomly determined the proposer suggests a division of a pie of size one each other agent either approves or rejects the proposal and the proposal is implemented if the set of approving agents is a winning coalition for the proposer the theory of the fixed point index is used to show that stationary equilibrium expected payoffs of this coalitional bargaining game are unique this generalizes eraslan 34 insofar as a there are no restrictions on the structure of sets of winning coalitions b different proposers may have different sets of winning coalitions c there may be a positive probability that no proposer is selected

efficient coalitional bargaining with noncontingent offers abstract a new feature pertaining to proposer s ability to implement offers is introduced in the extensive form bargaining mechanism studied in okada 1996 this mechanism is used to analyze the coalitional setting of strictly supermodular games the new feature in the mechanism is that the proposer has a choice to implement his proposal with any subset of responders who have accepted it thus the institutional feature of every responder has veto power is relaxed here it is shown that for all sufficiently high discount factors there exists an efficient subgame perfect equilibrium in pure stationary strategies sspe whose limiting outcome is the core constrained nash bargaining solution moreover all efficient sspe are payoff equivalent in the limit as 1

the coalitional nash bargaining solution the coalitional nash bargaining solution is defined to be the core allocation for which the product of players payoffs is maximal we consider a non cooperative model with discounting in which one team may form and every player is randomly selected to make a proposal in every period the grand team consisting of all players generates the largest surplus but a smaller team may form we show that as players get more patient if an efficient and stationary equilibrium exists it must deliver payoffs that correspond to the coalitional nash bargaining solution we also characterize when an efficient and stationary equilibrium exists which requires conditions that go beyond the nonemptiness of the core

legislative bargaining with heterogeneous disagreement values theory and experiments we study a legislative bargaining game in which failure to agree in a given round may result in a breakdown of negotiations in that case each player receives an exogenous disagreement value we characterize the set of stationary subgame perfect equilibria under all q majority rules under unanimity rule equilibrium payoffs are strictly increasing in disagreement values under all less than unanimity rules expected payoffs are either decreasing or first increasing and then decreasing in disagreement values we conduct experiments involving three players using majority and unanimity rule finding qualitative support for several but not all of our main predictions having a high disagreement value is indeed an advantage under unanimity under majority the player with the highest disagreement value is more likely to be excluded but this does not consistently result in a lower average payoff

legislative bargaining under weighted voting organizations often distribute resources through weighted voting we analyze this setting using a non cooperative bargaining game based on the baron ferejohn 1989 model unlike analyses derived from cooperative game theory we find that each voter s expected payoff is proportional to her voting weight an exception occurs when many high weight voters exist as low weight voters may expect disproportionately high payoffs due to proposal power the model also predicts that ex post the coalition formateur the party chosen to form a coalition will receive a disproportionately high payoff using data from coalition governments from 1946 to 2001 we find strong evidence ofsuch formateur effects

coalition formation as a dynamic process abstract 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

coalition theory and its applications a survey we survey some of the major advances in coalition theory in recent years we then look at the recent applications of the theory in the area of political economy and touch upon some important theoretical and applied open questions in the field

noncooperative foundations of the nucleolus in majority games abstract this paper studies coalition formation payoff division and expected payoffs in a divide the dollar by majority rule game with random proposers a power index is called self confirming if it can be obtained as an equilibrium of the game using the index itself as probability vector unlike the shapley value and other commonly used power indices the nucleolus has this property the proof uses a weak version of kohlberg s siam j appl math 20 1971 62 balancedness result reinterpreting the balancing weights as probabilities in a mixed strategy equilibrium

bargaining failures and merger policy in this paper we study the optimal ex ante merger policy in a model where merger proposals are the result of strategic bargaining among alternative candidates we allow for firm asymmetries and in particular we emphasize the fact that potential synergies generated by a merger may vary substantially depending on the identity of the participating firms the model demonstrates that under some circumstances relatively inefficient mergers may take place that is a particular merger may materialize despite the existence of an alternative merger capable of generating higher social surplus and even higher profits such bargaining failures have important implications for the ex ante optimal merger policy we show that a more stringent policy than the ex post optimal reduces the scope of these bargaining failures and raises expected social surplus we use a bargaining model that is flexible in the sense that its strategic structure does not place any exogenous restriction on the endogenous likelihood of feasible mergers

proposal power and majority rule in multilateral bargaining with costly recognition this paper studies a sequential bargaining model in which agents expend efforts to be the proposer in equilibrium agents effort choices are influenced by the prize and cost effects the endogenous prize is 9

subscription mechanisms for network formation we analyze a model of network formation where the costs of forming links are publicly known but an individual s benefits are not known to the social planner the objective is to design a mechanism which not only ensures that an efficient network always forms in equilibrium but also ensures that the resulting net payoffs to the agents are equitable we propose two mechanisms towards this end in the first agents announce sequentially the set of players with whom they wish to form links and a cost contribution we show that all subgame perfect equilibria of this game result in the formation of an efficient network but the resulting net payoffs are asymmetric the second mechanism corrects this asymmetry through a two stage variant of the first mechanism we also discuss an extension of the basic model to cover the case of directed graphs and give conditions under which the proposed mechanisms are immune to deviations by coalitions

caste and credit a woeful tale this paper examines caste based differences in farmers access to bank loans in rural india we investigate whether banks practice taste based discrimination on the basis of caste in order to identify potential discrimination we consider loan applications and approval decisions separately we find significant inter caste differences in application rates and evidence of discrimination against scheduled tribe borrowers at the approval stage to rule out the role of statistical discrimination we simulate unobserved credit histories with various distributions evidence for taste based discrimination persists despite accounting for unobservables however we find that this discrimination does not affect small farmers

bargaining delay under partial breakdowns and externalities abstract we consider a noncooperative coalitional bargaining game where partial breakdowns such as the rejecter of a proposal exiting from the game take place with a positive probability and externalities accompany the formation of coalitions we present an example in which there exists a stationary subgame perfect equilibrium sspe such that a bargaining delay occurs we also show that under no partial breakdowns or no externalities delay does not occur in any sspe

a noncooperative coalitional bargaining game with random proposers abstract we extend the stahl rubinstein s alternating offer model ton person coalitional bargaining the key feature of the model is the random selection of proposers at every round no delay of agreement occurs in equilibrium for a super additive game in contrast to the fixed order model of chatterjeeet al rev econ stud 60 1993 463 477 when the discount factor of future payoffs is sufficiently high the agreement on the grand coalition is reached if and only if it has the largest value per capita among all coalitions moreover in the limit as the discount factor goes to one all players divide equally the value of the grand coalition regardless of who makes a proposal journal of economic literatureclassification numbers c72 c73 c78

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