The separability principle in bargaining

Summary. We investigate the implications of the separability principle in the context of bargaining. For two bargaining problems with the same population, suppose that there is a subgroup of agents who receive the same payoffs in both bargaining problems. Moreover, if we imagine the departure of this subgroup with their payoffs, then the remaining agents face the same opportunities in both bargaining problems. The separability principle requires that under these hypotheses, the remaining agents should receive the same payoffs in both bargaining problems. We begin with investigating the logical relations between separability and two other axioms, contraction independence and consistency. Then, we establish characterizations of the Nash and egalitarian solutions on the basis of separability. Received: 12 August 2002, Revised: 22 March 2004, JEL Classification Numbers: C71, C78.Youngsub Chun: This work was supported by the Brain Korea 21 Project in 2003. I am grateful to William Thomson, a referee, and an associate editor for their valuable comments.     

Walrasian bargaining

Given any two-person economy, consider an alternating-offer bargaining game with complete information where the proposers offer prices, and the responders either choose the amount of trade at the offered prices or reject the offer. We provide conditions under which the outcomes of all subgame-perfect equilibria converge to the Walrasian equilibrium (the price and the allocation) as the discount rates approach 1. Therefore, price-taking behavior can be achieved with only two agents.     

On continuous-time Markov processes in bargaining

For bilateral stochastic bargaining procedures embedded in stable homogeneous continuous-time Markov processes, we show unusual limit results when time between rounds vanish. Standard convergence results require that some states are instantaneous.     

Unemployment, wage bargaining and capital-labour substitution

Many economists believe that capital accumulation, technicalprogress and labour force expansion have no lasting effect onunemployment. This view rests on the empirically doubtful assumptionthat the elasticity of substitution between labour and capitalis equal to unity (i.e., production is Cobb-Douglas). Usinga simple model based on the work of Layard, Nickell and Jackman,this paper demonstrates that, with a lower elasticity of substitution,the equilibrium unemployment rate is affected by all of theabove factors. It considers briefly how capital accumulationmay be endogenised and what long-run implications this has forunemployment.     

Stationary equilibria in bargaining with externalities

This paper studies infinite-horizon bargaining between a seller and multiple buyers when externalities are present. We extend the analysis in Jehiel and Moldovanu by allowing for both pure and mixed equilibria [Jehiel, P., Moldovanu, B., 1995a. Cyclical delay in bargaining with externalities. Rev. Econ. Stud. 62, 619–637]. A characterization of the stationary subgame perfect equilibria in generic games is presented. Equilibria with delay exist only for strong positive externalities. Since each buyer receives a positive payoff when the seller makes an agreement with some other buyer, positive externalities induce a war of attrition between buyers.     

Focal points and bargaining in housing markets

Are focal points important for determining the outcome of high-stakes negotiations? We investigate this question by examining the role that round numbers play as focal points in negotiations in the housing market. Using a large dataset on home transactions in the U.S., we document sharp spikes in the distribution of final negotiated house prices at round numbers, especially those divisible by $50,000. The patterns cannot be easily explained by simple stories of convenience rounding or by list prices. We conclude that round numbers can serve as focal points, even in settings with very high stakes.     

Malice and patience in Rubinstein bargaining

If two players playing a Rubinstein alternating offers game are highly malicious (getting a high utility from “malice” in every period when the other player does not obtain a share in a fixed pie), and highly patient, no equilibrium with an agreement exists and players choose perpetual disagreement. This does not change if the players are subjected to a known deadline after which the pie will be appropriated by outside agencies or disappear: perpetual disagreement is still the only outcome. If in addition players are required to pay endogenously determined fines if they fail to reach agreement, players with discount factors in a certain range do reach agreement, but only at the deadline. However, infinitely patient players would never reach agreement for any feasible level of one-time fines. The result contrasts with spiteful or envious preferences. Our results highlight a novel reason for failure to resolve property disputes.     

Noncooperative foundations of bargaining power in committees and the Shapley–Shubik index

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.     

Subbalanced games and bargaining sets

Summary. In defining a bargaining set, it is desirable to require that a counterobjecting coalition has a non-empty intersection with the objecting coalition. We refer to this as the intersection property and define a bargaining set, MB ₁, that imposes this property on a variant of the bargaining set defined by Vohra (1991). To study the existence of MB ₁, a new version of the KKM theorem is proposed and the concept of a subbalanced game is introduced. We also provide conditions for the non-emptiness of MB ₂, a bargaining set introduced by Zhou (1994) which imposes the additional restriction that the objecting coalition not be a subset of the counterobjecting coalition.Received: 9 December 2002, Revised: 6 December 2004, JEL Classification Numbers: C71. Correspondence to: Chih ChangThe authors are very grateful to a referee who proposes many helpful comments on both substantive matters and exposition which much improve the paper.     

The inefficiency of price quantity bargaining

In bargaining between a buyer and several sellers on prices and quantities, strategic inefficiencies arise. By reallocating quantities between agreements, the buyer can increase its share of the surplus. With two symmetric sellers producing substitutes, the quantity in the first agreement will be higher than the efficient quantity, and the quantity in the last lower, thus implying that sellers are strategically discriminated. When asymmetries are not too large and sellers produce substitutes, the buyer first agrees with the seller with the lowest marginal cost and only the most efficient order of agreement is an equilibrium outcome. When goods are complements, both equilibrium quantities are lower than the efficient levels.     

Dissertation abstract: Essays on veto bargaining games

This dissertation experimentally analyzes the outcomes of multilateral legislative bargaining games in the presence of a veto player. The first essay examines veto power—the right of an agent to unilaterally block decisions but without the ability to unilaterally secure his/her preferred outcome. Using Winter’s (1996) theoretical framework, I consider two cases: urgent committees where the total amount of money to be distributed shrinks by 50% if proposals do not pass and non-urgent committees where the total amount of money shrinks by 5% if proposals do not pass. Committees with a veto player take longer to reach decisions (are less efficient) than without a veto player and veto players proposals generate less consensus then non-veto players proposals, outcomes on which the theory is silent. In addition, veto power in conjunction with proposer power generates excessive power for the veto player. This suggests that limiting veto players’ proposer rights (e.g., limiting their ability to chair committees) would go a long way to curbing their power, a major concern in committees in which one or more players has veto power. Finally, non-veto players show substantially more willingness to compromise than veto players, with players in the control game somewhere in between. I relate the results to the theoretical literature on the impact of veto power as well as concerns about the impact of veto power in real-life committees. The second essay discusses in detail the voting patterns in the veto and control games reported in the first essay. The empirical cumulative density functions of shares veto players accepted first degree stochastically dominates that of shares for the controls and the empirical cdfs of shares the controls accepted first degree stochastically dominate that of shares for non-veto players. Random effect probits support this conclusion as well. In addition, regressions imply favorable treatment of voting and proposing between non-veto players which, however, does not result in larger shares in the end. Coalition partners consistently demand more than the stationary subgame perfect Nash equilibrium share except for veto players in non-urgent committees. JEL Classification C7, D7, C78, D72 Dissertation Committee: John H. Kagel, Advisor Massimo Morelli Alan Wiseman Stephen Cosslett     

Markov equilibria in dynamic matching and bargaining games

Rubinstein and Wolinsky [Rev. Econ. Stud. 57 (1990) 63] show that a simple homogeneous market with exogenous matching has a continuum of (non-competitive) perfect equilibria; however, the unique Markov-perfect equilibrium of this model is competitive. By contrast, in the more general case of heterogeneous markets, even the Markov property is not enough to guarantee the perfectly competitive outcome. We define a market game that allows for heterogeneous values on both sides of the market and exhibit a number of examples of (non-competitive) Markov-perfect equilibria, with and without discounting. Unlike the homogeneous case, these equilibria allow for inefficient trades and for trade at non-uniform prices. The non-competitive equilibrium may be unique.     

Alternating-offer bargaining over menus under incomplete information

Summary. This paper considers bargaining with one-sided private information and alternating offers where an agreement specifies both a transfer and an additional (sorting) variable. Moreover, both sides can propose menus. We show that for a subset of parameters the alternating-offer game has a unique equilibrium where efficient contracts are implemented in the first period. This stands in sharp contrast to the benchmarks of contract theory, where typically only the uninformed side proposes, and bargaining theory, where typically the agreement only specifies a transfer. Received: September 10, 2001; revised version: March 25, 2002 RID="*" ID="*" I benefitted from discussions with Benny Moldovanu, Holger Müller, and Roland Strausz, and from comments made by an anonymous referee.     

Multilateral bargaining: conditional and unconditional offers

Summary. We present a game in which n persons split a cake, where a distinction between conditional and unconditional offers is made. This distinction sheds light on the contrasting results obtained in the previous literature of multilateral bargaining. By allowing the proposer to make both conditional and unconditional offers, we show that the game has a unique subgame perfect Nash equilibrium outcome. Received: March 14, 2000; revised version: March 13, 2001     

Fragmented property rights and royalty bargaining

We consider production by a firm that relies on the patent rights that are held by other actors. Before production can take place, bargains have to be struck with each patent holder over the royalty per unit produced. In the negotiations, a patent holder must be mindful of the fact that a large royalty will increase the product price and lower demand for the final product. Hence each patent holder would prefer to gain a large royalty at the expense of rivals. When the producer makes the first offer in an alternating offer framework, we analyze whether it should conduct negotiations sequentially with some grouping of patent holders or simultaneously. We demonstrate that the producer will prefer simultaneous negotiation. An individual patent holder would prefer to negotiate early with the producer, and then to see remaining rights holders negotiate simultaneously. A firm that holds several patents would want to negotiate royalties on each one sequentially and then have simultaneous negotiation of payments to other rights holders.     

Sunk costs and fairness in incomplete information bargaining

We study a bilateral trading relationship in which one agent, the seller, can make a nonrecoverable investment in order to generate potential gains from trade. Afterwards, the seller makes a price offer that the buyer can either accept or reject. If agents are fairminded, sellers who are known by the buyer to have high investment costs are predicted to charge higher prices. If the investment cost is private information, low-cost sellers should price more aggressively and high-cost sellers less aggressively than under complete information, giving rise to disagreement and/or underinvestment. Our experiment support these predictions.     

Competition and bargaining in vertical relationships with market uncertainty

We go through the decision to vertically integrate or its opposite, outsource, in an uncertain environment. We consider two different market strategies, price setting and quantity setting and two different vertical relationships: an (imperfectly) competitive one following Stackelberg mode and a more cooperative one with bargaining. In the first scenario, with certainty, price and quantity settings are alike, while with uncertainty the ranking changes. If a bargaining framework is adopted instead, quantity setting under uncertainty leads to an asymmetric distribution of realized gains along the vertical chain. Price setting turns out to be more equitable for firms and preferable even by consumers.

Tough negotiations: Bilateral bargaining with durable commitments

We offer a tractable model of tough negotiations and delayed agreement. The setting is an infinite horizon bilateral bargaining game in which negotiators can make strategic commitments to durable offers. Commitments decay stochastically, but uncommitted negotiators can make new commitments. The game's unique Markov Perfect equilibrium outcome takes the form of a war of attrition: Negotiators initially commit to incompatible offers, but agreement occurs once a negotiator's commitment decays. If commitments decay more quickly, the terms of the agreement become more equal. In expectation, more patient, committed, and less risk averse negotiators obtain a larger fraction of the surplus.     

Union-oligopoly bargaining and entry deterrence: a reassessment of limit pricing

This paper introduces wage bargaining in the framework of Milgrom and Roberts (Econometrica 50(2):443–459, 1982) where the workers’ reservation wage is the private information parameter critical for entry. We show that entry threat significantly distorts the wage, which in some cases adversely affects the firm’s ability to signal through price. Consequently, the separating equilibrium (in price) does not always exist. If, however, wage agreements are made public, signalling occurs with or without distortions in wage depending on whether the union’s bargaining power is high or low. Pooling equilibrium also exists and it features similar distortions. We also examine which signal, wage or price, generates greater social welfare. We would like to thank two referees for their helpful comments and suggestions. This paper is partially based on a chapter of Pal’s PhD thesis done at Indira Gandhi Institute of Development Research (IGIDR), India. For remaining errors we are solely responsible.