On the consistency of stationary Markov equilibria with an exogenous distribution

A technique to show the existence of stationary Markov equilibria is provided by Duffie, Geanakoplos, Mas-Colell and McLennan Econometrica 62 (1994) 745-781. In many applications, a state space is constructed as the product of a space of exogenous variables and a space of endogenous variables. In addition, the exogenous shock is given and is a Markov process with a transition probability and an initial distribution. Then their theorem does not ensure the existence of a stationary Markov equilibrium that is consistent with the exogenous distribution. In this paper, we give a sufficient condition for settling the inconsistency problem.     

On the convergence to the Nash bargaining solution for action-dependent bargaining protocols

We consider a non-cooperative multilateral bargaining game and study an action-dependent bargaining protocol, that is, the probability with which a player becomes the proposer in a round of bargaining depends on the identity of the player who previously rejected. An important example is the frequently studied rejector-becomes-proposer protocol. We focus on subgame perfect equilibria in stationary strategies which are shown to exist and to be efficient. Equilibrium proposals do not depend on the probability to propose conditional on the rejection by another player. We consider the limit, as the bargaining friction vanishes. In case no player has a positive probability to propose conditional on his rejection, each player receives his utopia payoff conditional on being recognized. Otherwise, equilibrium proposals of all players converge to a weighted Nash bargaining solution, where the weights are determined by the probability to propose conditional on one's own rejection.     

One-dimensional bargaining with Markov recognition probabilities

We study a process of bargaining over alternatives represented by points in the unit interval. The paper focuses on the asymptotic behavior of the subgame perfect equilibrium in stationary strategies as the continuation probability approaches one. We give a complete characterization of the limit of the equilibrium proposals as the generalized fixed point of the decumulative distribution of the players' ideal points as induced by the recognition probabilities. In contrast to the existing literature, we find no general relationship between the limit equilibrium proposals and either the Nash bargaining solution or the median voter outcome.     

Decentralized trade, random utility and the evolution of social welfare

We study decentralized trade processes in general exchange economies and house allocation problems with and without money. The processes are affected by persistent random shocks stemming from agents’ maximization of random utility. By imposing structure on the utility noise term—logit distribution—one is able to calculate exactly the stationary distribution of the perturbed Markov process for any level of noise. We show that the stationary distribution places the largest probability on the maximizers of weighted sums of the agents’ (intrinsic) utilities, and this probability tends to 1 as noise vanishes.     

Optimal development programs under uncertainty: The undiscounted case

One considers a many-commodity world where technology depends on an exogenous environment whose successive states form a stationary Markov process. A program is optimal if it overtakes any other program or has the maximum expected utility.It is shown there exists a best stationary program. One proves then there exists an optimal program, which converges asymptotically to the best stationary program, and is generated by a policy such that, at every date, a nonrandom production decision is chosen which depends only on the state of the world and of the economy at that time.     

Sequential bargaining in a market with one seller and two different buyers

A matching and bargaining model in a market with one seller and two buyers, differing only in their reservation price, is analyzed. No subgame perfect equilibrium exists for stationary strategies. We demonstrate the existence of inefficient equilibria in which the low buyer receives the good with large probability, even as friction becomes negligible. We investigate the relationship between the use of Nash and sequential bargaining. Nash bargaining seems applicable only when the sequential approach yields a unique stationary strategy subgame perfect equilibrium.     

Bargaining and efficiency in networks

We study an infinite horizon game in which pairs of players connected in a network are randomly matched to bargain over a unit surplus. Players who reach agreement are removed from the network without replacement. The global logic of efficient matchings and the local nature of bargaining, in combination with the irreversible exit of player pairs following agreements, create severe hurdles to the attainment of efficiency in equilibrium. For many networks all Markov perfect equilibria of the bargaining game are inefficient, even as players become patient. We investigate how incentives need to be structured in order to achieve efficiency via subgame perfect, but non-Markovian, equilibria. The analysis extends to an alternative model in which individual players are selected according to some probability distribution, and a chosen player can select a neighbor with whom to bargain.     

Public trust and government betrayal

This study presents a simple model of government reputation (in which government type cannot be directly observed by households) with the variation that government type, rather than being permanent, follows an exogenous Markov process. This formulation captures three characteristics of bad policy outcomes: governments which betray public trust do so erratically, public trust is regained only gradually after a betrayal, and governments with recent betrayals betray with higher probability than other governments.     

A bargaining model in general equilibrium

The goal of the paper is to present a simple model of rational endogenous household formation in a general equilibrium framework in which Pareto optimality at the economy level is not necessarily obtained. The simplest example of household formation is the case in which pairs of individuals engage themselves in a bargaining process on the division of some wealth: if an agreement on the distribution is (not) reached, we can say that the household is (not) formed. The vast majority of existing bargaining models predicts agreements on an efficient outcome. A seminal paper by Crawford (Econometrica 50:607–637, 1982) describes a very simple game with incomplete information in which, even with rational agents, disagreement causes welfare losses. We embed that model in a general equilibrium framework and present some results on equilibria both in the bargaining game and the associated exchange economy. Crawford’s results support Schelling’s intuition on the reasons of disagreement: it may arise if players’ commitments are reversible. Crawford shows that high probabilities of reversibility tend to favor the bargaining impasse, in fact with low probability. We prove that even if those probabilities are arbitrarily close to zero, disagreement is an equilibrium outcome, with high probability. That conclusion seems to be an even stronger support to Schelling’s original viewpoint. In the exchange economy model with that noncooperative bargaining game as a first stage, we present significant examples of economies for which equilibria exist. Because of disagreement, Pareto suboptimal exchange economy equilibria exist for all elements in the utility function and endowment spaces and they may coexist with Pareto optimal equilibria even at the same competitive prices.     

Consumption loans under uncertainty

A stationary equilibrium for a sequence of markets under uncertainty is defined as a stationary stochastic process of temporary market equilibria. The purpose of this paper is to apply this equilibrium concept to a consumption-loans model with stochastic resources. Given that agents live for only two periods, that resources are allocated independently and identically, and that traders make “admissible” consumption decisions, it is shown that the sequence of equilibrium trades on forward markets is a Markov chain. When this chain is strictly stationary with a unique invariant distribution, the sequence of markets is in stationary equilibrium. Using Gale's classification scheme, a strictly stationary chain exists for each type of economy (classical, Samuelson, mixed). Questions concerning convergence to the invariant distribution for each type of economy are addressed by determining when the chain satisfies various recurrence conditions.     

AN EMPIRICAL STATIONARY EQUILIBRIUM SEARCH MODEL OF THE HOUSING MARKET*

This article specifies and estimates a computationally tractable stationary equilibrium model of the housing market. The model is rich and incorporates many of its unique features: buyers’ and sellers’ simultaneous search behavior, heterogeneity in their motivation to trade, transaction costs, a trading mechanism with posting prices and bargaining, and the availability of an exogenous advertising technology that induces endogenous matching. Estimation uses Maximum Likelihood methods and Multiple Listing Services data. The estimated model is used to simulate housing market outcomes when (a) the amount of information displayed on housing listings increases and (b) real estate agent’s commission rates change.     

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.     

Stochastic bequest games

In this paper, we prove the existence of a stationary Markov perfect equilibrium for a stochastic version of the bequest game. A novel feature in our approach is the fact that the transition probability need not be non-atomic and therefore, the deterministic production function is not excluded from consideration. Moreover, in addition to the common expected utility we also deal with a utility that takes into account an attitude of the generation towards risk.     

Search theory,competitive equilibrium,and the Nash bargaining solution

We investigate a canonical search-theoretic model without entry. Two agents are randomly matched with a long side being rationed. The matched agents face a pair of randomly drawn non-transferable payoffs, and then choose whether or not to form a partnership subject to a small probability of exogenous break down. As this probability and friction vanish, the Nash bargaining solution emerges as the unique undominated strategy equilibrium outcome if the mass of each party is the same. If the size of one party is larger than the other, the short side extracts the entire surplus, a sharp contrast to Rubinstein and Wolinsky (1985) [16].     

The Dynamics of Trustworthiness Among the Few

Conventional stochastic models of evolutionary processes with infinitely many agents are deterministic models in disguise. Only finite population models become truly stochastic. Therefore this paper focuses on an indirect evolutionary model of pair wise interaction in a pool of three (corresponding to analysing oligopolies in terms of duopoly markets). The outcomes of the process over the long haul are characterized by the stationary distribution of the underlying Markov process. Our example indicates that intermediate cases cannot be seen as convex combinations of the two polar non-stochastic cases of two or infinitely many individuals.
JEL Classification Numbers: C72, C73.     

Uniqueness of stationary equilibria in a one-dimensional model of bargaining

We prove uniqueness of stationary equilibria in a one-dimensional model of bargaining with quadratic utilities, for an arbitrary common discount factor. For general concave utilities, we prove existence and uniqueness of a “minimal” stationary equilibrium and of a “maximal” stationary equilibrium. We provide an example of multiple stationary equilibria with concave (nonquadratic) utilities.     

Non-cooperative bargaining and the incomplete informational core

In an exchange economy with incomplete information, the signaling core is defined by the set of state-contingent allocations to which no coalitions object under informational leakage through proposals by informed agents. An objection underlying the signaling core is supported by a sequential equilibrium of an ultimatum bargaining game with an informed proposer. We prove that a stationary sequential equilibrium allocation in a Rubinstein-type sequential bargaining game with a restart rule belongs to the signaling core if the belief of players satisfies a self-selection property.     

Strategic Bargaining and Competitive Bidding in a Dynamic Market Equilibrium

This paper extends the bargaining and matching literature, such as Rubinstein and Wolinsky (1985), by considering a new matching process. We assume that a central information agency exists, such as real estate agencies in the housing market and employment agencies (or newspapers) in the labour market, which puts traders into direct contact with each other. With heterogeneity of trader preferences, equilibrium trade is characterized by existing traders on each side of the market trying to match with the flow of new traders on the other side (since existing traders have already sampled and rejected each other). Two procedures of trade co-exist, namely a strategic bilateral bargaining process and a competitive bidding process, depending on the number of potential matches a new trader obtains. We characterize the unique symmetric Markov perfect equilibrium to this stochastic trading game.     

Bargaining with random implementation: An experimental study

We use a laboratory experiment to study bargaining with random implementation. We modify the standard Nash demand game so that incompatible demands do not necessarily lead to the disagreement outcome. Rather, with exogenous probability q, one bargainer receives his/her demand, with the other getting the remainder. We use an asymmetric bargaining set (favouring one bargainer) and disagreement payoffs of zero, and we vary q over several values.Our results mostly support game theoryʼs directional predictions. As with conventional arbitration, we observe a strong chilling effect on bargaining for q near one: extreme demands and low agreement rates. Increasing q reinforces the gameʼs built-in asymmetry – giving the favoured player an increasingly large share of payoffs – but also raising efficiency. These effects are non-uniform: over sizable ranges, increases in q have minimal effect, but for some q, small additional increases lead to sharp changes in results.     

A Closed Form Characterization of the Stationary Outcome in Multilateral Bargaining

In this paper we consider infinite horizon multilateral bargaining with alternate offers. We prove that there exists only one stationary subgame perfect equilibrium outcome and it corresponds to the unique invariantmeasure of a column stochastic matrix. We characterize this stationary subgame perfect equilibrium outcome in a closed form, and also extend the approach to the multilateral bargaining with random moves.