power illusion in coalitional bargaining an experimental analysis abstract one feature of legislative bargaining in naturally occurring settings is that the distribution of seats or voting weights often does not accurately reflect bargaining power game theoretic predictions about payoffs and coalition formation are insensitive to nominal differences in vote distributions and instead only depend on pivotality we conduct an experimental test of the classical baron ferejohn model with five player groups holding real power constant we compare treatments with differences in nominal power we find that initial effects of nominal differences become small or disappear with experience our results also point to the complexity of the environment as having a negative impact on the speed at which this transition takes place finally and of particular importance as a methodological observation giving subjects a pause accelerates learning

uniqueness of stationary equilibrium payoffs in the baron ferejohn model abstract we consider a multilateral sequential bargaining model in which the players may differ in their probability of being selected as the proposer and the rate at which they discount future payoffs for games in which agreement requires less than unanimous consent we characterize the set of stationary subgame perfect equilibrium payoffs with this characterization we establish the uniqueness of the equilibrium payoffs for the case where the players have the same discount factor we show that the payoff to a player is nondecreasing in his probability of being selected as the proposer for the case where the players have the same probability of being selected as the proposer we show that the payoff to a player is nondecreasing in his discount factor journal of economic literature classification numbers c72 c78 d70

bargaining foundations of shapley value1 a transferable utility economy in which each agent holds a resource which can be used in combination with the resources of other agents to generate value according to the characteristic function v is studied using a dynamic model of bargaining the main theorem establishes that the payoffs associated with efficient equilibria converge to the agents shapley values as the time between periods of the dynamic game goes to zero in addition it is demonstrated that an efficient equilibrium exists and is unique when an additivity condition is satisfied to demonstrate the sensitivity of the solution to the institutional detail we modify the model to allow for partnerships and show that the shapley value is no longer achieved

bargaining and value we present and analyze a model of noncooperative bargaining among n participants applied to situations describable as games in coalitional form this leads to a unified solution theory for such games that has as special cases the shapley value in the transferable utility tu case the nash bargaining solution in the pure bargaining case and the recently introduced maschler owen consistent value in the general nontransferable utility ntu case moreover we show that any variation in a certain class of our bargaining procedure which generates the shapley value in the tu setup must yield the consistent value in the general ntu setup

the power of the proposal maker in a model of endogenous agenda formation in a distributive setting this study examines a voting procedure for which agenda formation is endogenous it is found not surprisingly that agenda formation is another avenue for strategic manipulation of the voting process and provides the member to first take the floor an asymmetric advantage what is surprising is the degree of this advantage we find that the initial proposal maker earns a share of the fixed resource exceeding 1 for an majority rule and this is regardless of the number of members the voting rule is found to be an effective instrument in at least partially offsetting the power of the proposal maker while maintaining the stability of the voting process

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

inequity aversion may increase inequity inequity aversion models have been used to explain equitable payoff divisions in bargaining games i show that inequity aversion can actually increase the asymmetry of payoff division if unanimity is not required this is because responders may be willing to accept a lower share rather than risk being left out inequity aversion may also affect comparative statics the advantage of being the proposer can decrease as players become more impatient game theory usually assumes that players care only about their own material payoffs this hypothesis is clearly refuted by the experimental evidence in the ultimatum and related games see camerer 2003 for a recent survey inequity aversion theories have been developed in order to account for the stylised facts observed in the laboratory see fehr and schmidt 1999 and bolton and ockenfels 2000 inequity aversion means that people are willing to give up some material payoffs in order to achieve more equitable outcomes inequity averse responders prefer to reject small offers in the ultimatum game and the proposers anticipating this make higher offers in this article i examine the implications of inequity aversion for bargaining games in which unanimity is not required e g legislative bargaining games and show that it may lead to a more inequitable outcome than would occur with selfish preferences the leading model of legislative bargaining is due to baron and ferejohn 1989 in this model n symmetric players must divide a budget by simple majority each player has an equal chance of being chosen to propose a division of the budget once a proposal is made the remaining players vote yes or no if a majority of the players supports the proposal it is implemented and the game ends otherwise the procedure is repeated this model predicts that minimal winning coalitions will form and that the proposer will receive a disproportionate share of the proceedings thus the equilibrium of the baron ferejohn model with selfish preferences exhibits a substantial amount of inequity some players are excluded almost half of them if the decision rule is simple majority and the proposer receives a substantial share more than half of the total payoff if the decision rule is simple majority the advantage of the proposer increases as players become more impatient or more risk averse the baron ferejohn model has led to many applications and extensions 1 in its simplest form it assumes that parties are selfish risk neutral and only concerned with their share of cabinet posts as opposed to policy the predictions of the model under these assumptions have been tested by ansolabehere et al 2005 using data on the

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

a bargaining model of collective choice we present a general model of legislative bargaining in which the status quo is an arbitrary point in a multidimensional policy space in contrast to other bargaining models the status quo is not assumed to be bad and delay may be pareto efficient we prove existence of stationary equilibria the possibility of equilibrium delay depends on four factors risk aversion of the legislators the dimensionality of the policy space the voting rule and the possibility of transfers across districts if legislators are risk averse if there is more than one policy dimension and if voting is by majority rule for example then delay will almost never occur in one dimension delay is possible if and only if the status quo lies in the core of the voting rule and then it is the only possible outcome this core selection result yields a game theoretic foundation for the well known median voter theorem our comparative statics analysis yield two noteworthy insights i if the status quo is close to the core t hen equilibrium policy outcomes will also be close to the core a moderate status quo produces moderate policy outcomes and ii if legislators are patient then equilibrium proposals will be close to the core legislative patience leads to policy moderation

noncooperative foundations of bargaining power in committees and the shapley shubik index abstract in this paper we explore the noncooperative foundations of the bargaining power that a voting rule gives to each member of a committee that bargains in search of consensus over a set of feasible agreements under a voting rule assuming complete information we model a variety of bargaining protocols and investigate their stationary subgame perfect equilibria we show how the shapley shubik index and other power indices can be interpreted as measures of bargaining power that appear in this light as limit cases

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

the german hyperinflation and the demand for money revisited this paper shows that a remarkably well defined demand for real balances exists for the german hyperinflation episode including the final months which have previously been considered as outliers the authors econometric analysis exploits the theory of cointegration given the obvious nonstationarity of the data further they consider two likely sources of misspecification income variability and the necessity to distinguish between the high inflation and hyperinflation episodes copyright 1994 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

reinterpreting the kernel the reduced game relevant for the consistency of the prekernel is used to reinterpret this solution concept in a way that makes it independent of interpersonal utility comparisons based on this reinterpretation a non cooperative model is presented that yields in stationary equilibria the prekernel kernel for the class of monotonic transferable utility games next we apply the same non cooperative model to more general coalitional games for pure bargaining problems the model yields the nash solution for general non transferable utility games a natural extension of the prekernel arises thus the prekernel is obtained as the set of payoffs where the relevant bargaining range between every pair of players is split in half journal of economic literatureclassification numbers c71 c72 c78

coalitional bargaining games with random proposers theory and application abstract we consider a non cooperative coalitional bargaining game with random proposers in a general situation for which players differ in recognition probability and time preference we characterize an efficient equilibrium as the generalized nash bargaining solution that belongs to the core the model is applied to wage bargaining between an employer and multiple workers although involuntary unemployment may occur in equilibrium full employment emerges as players become sufficiently patient

voting and vetoing the consequences of veto power in committees is analyzed using the appro ach of noncooperative bargaining theory it is first shown that in equilibrium nonveto players do not share in the benefits gained by the decision making of the committee that is in every equilibrium outcome of the bargaining game nonveto players earn zero some measures for reducing the excessive power of veto members in committees are analyzed specifically i study the effects of imposing a deadline on negotiations and of expanding the committee by increasing the number of nonveto players quantitative results are given for the case of the un security council

informational channels of financial contagion two main classes of channels are studied as informational sources of financial contagion one is a fundamental channel that is based on real and financial links between economies and the second is a social learning channel that arises when agents base their decisions on noisy observations about the actions of others in foreign markets using global games i present a two country model of financial contagion in which both channels can operate and i test its predictions experimentally the experimental results show that subjects do not extract information optimally which leads to two systematic biases that affect these channels directly base rate neglect leads subjects to underweight their prior and thus weakens the fundamental channel an overreaction bias strengthens the social learning channel since subjects rely on information about the behavior of others even when this information is irrelevant these results have significant welfare effects rooted in the specific way in which these biases alter behavior

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

on market games when agents cannot be in two places at once abstract we consider markets in which agents supply their time or the services of a capital good and the duration of the market is limited we show that a coalitional game can be generated by such a market if and only if the characteristic function of the game is superadditive journal of economic literature classification numbers c71 d51

behavioral identification in coalitional bargaining an experimental analysis of demand bargaining and alternating offers alternating offer and demand bargaining models of legislative bargaining make very different predictions in terms of both ex ante and ex post distribution of payoffs as well as in the role of the order of play the experiment shows that actual bargaining behavior is not as sensitive to the different bargaining rules as the theoretical point predictions whereas the comparative statics are in line with both models we compare our results to studies that attempt to distinguish between these two approaches using field data finding strong similarities between the laboratory and field data regardless of the underlying bargaining process

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

value consistency and random coalition formation abstract given an n player cooperative game and a feasible age n vector suppose that the players in a cooperative game are randomly split into two coalitions each with a randomly chosen leader the two leaders bargain bilaterally and each pays out of his share a wage to each member of his coalition as specified by the wage vector the wage vector is said to be consistent with the above procedure if it is equal to the ex ante expected payoff vector we prove that if all 2 coalition partitions are equally likely and if the bilateral bargain splits the surplus equally then the unique consistent payoff vector is the shapley value an equivalent consistency result holds for partitions with more than two elements these results are related to gul s 1989 result on noncooperative implementation of the shapley value journal of economic literature classification number 026