Engodeneity of Alternating Offers in a Bargaining Game

We investigate an infinite horizon two-person simultaneous offer bargaining game of incomplete information with discounted playoffs. In each period, each player chooses to give in or hold out. The game continues until at least one of the players chooses to give in, at which point agreement has been reached and the game terminates, with an agreement benefit accruing to each player, and a cost to the player (or players) that give in. Players have privately known agreement benefits. 'Low benefit players have a weakly dominant strategy to hold out forever; high benefit players would be better off giving in if they knew their opponent was planning to hold out forever. For any discount factor there is a unique Nash equilibrium in which the two players alternate in their willingness to give in, if the players' priors about each others type are sufficiently asymmetric. Second, for almost all priors, this is the unique equilibrium if the discount factor is close enough to one

An Experimental Study of the Centipede Game

We report on an experiment in which individuals play a version of the centipede game. In this game, two players alternately get a chance to take the larger portion of a continually escalating pile of money. As soon as one person takes, the game ends with that player getting the larger portion of the pile, and the other player getting the smaller portion. If one views the experiment as a complete information game, all standard game theoretic equilibrium concepts predict the first mover should take the large pile on the first round. The experimental results show that this does not occur. An alternative explanation for the data can be given if we reconsider the game as a game of incomplete information in which there is some uncertainty over the payoff functions of the players. In particular, if the subjects believe there is some small likelihood that the opponent is an altruist, then in the equilibrium of this incomplete information game, players adopt mixed strategies in the early rounds of the experiment, with the probability of taking increasing as the pile gets larger. We investigate how well a version of this model explains the data observed in the centipede experiments

Quantal Response Equilibria for Extensive Form Games

This paper investigates the use of standard econometric models for quantal choice to study equilibria of extensive form games. Players make choices based on a quantal choice model, and assume other players do so as well. We define an Agent Quantal Response Equilibrium (AQRE), which applies QRE to the agent normal form of an extensive form game and imposes a statistical version of sequential rationality. We also define a parametric specification, called logit-AQRE, in which quantal choice probabilities are given by logit response functions. AQRE makes predictions that contradict the invariance principle in systematic ways. We show that these predictions match up with some experimental findings by Schotter, Weigelt and Wilson (1993) about the play of games that differ only with respect to inessential transformations of the extensive form. The logit-AQRE also implies a unique selection from the set of subgame perfect equilibria in generic extensive form games. We examine data from signalling game experiments by Banks, Camerer, and Porter (1994) and Brandts and Holt (1993). We find that the logit-AQRE selection applied to these games succeeds in predicting patterns of behavior observed in these experiments, even when our prediction conflicts with more standard equilibrium refinements, such as the intuitive criterion. We also reexamine data from the McKelvey and Palfrey (1992) centipede experiment

The Holdout Game: An Experimental Study of an Infinitely Repeated Game with Two-Sided Incomplete Information

We investigate experimentally a two-person infinitely repeated game of incomplete information. In the stage game, each player chooses to give in or hold out. Players have privately known costs of giving in and each player receives a fixed benefit whenever at least one player gives in. High cost players have a dominant strategy in the stage game to hold out, and the low cost players ' best response depends on what the opponent does. Equilibrium play to the infinitely repeated game conveys information about the players’ type. We investigate two questions: whether there is any evidence that subject behavior approximates belief stationary equilibria, and whether there is evidence that subjects will converge to an equilibrium of the correct state. We conclude that subjects do not adopt symmetric belief stationary strategies for the holdout game. However, we cannot reject the hypotheses that subjects converge towards eventually playing an equilibrium of the correct state (even though they do not always learn the correct state). Behavior of experienced subjects is closer to the predictions of symmetric belief-stationary equilibrium

An Experimental Study of Constant-sum Centipede Games

In this paper, we report the results of a series of experiments on a version of the centipede game in which the total payoff to the two players is constant. Standard backward-induction arguments lead to a unique Nash equilibrium outcome prediction, which is the same as the prediction made by theories of "fair" or "focal" outcomes. We find that subjects frequently fail to select the unique Nash outcome prediction. While this behavior was also observed in McKelvey and Palfrey (1992) in the "growing pie" version of the game they studied, the Nash outcome was not "fair", and there was the possibility of Pareto improvement by deviating from Nash play. Their findings could therefore be explained by small amounts of altruistic behavior. There are no Pareto improvements available in the constant-sum games we examine, hence explanations based on altruism cannot account for these new data. We examine and compare two classes of models to explain this data. The first class consists of non-equilibrium modifications of the standard "Always Take" model. The other class we investigate, the Quanta! Response Equilibrium model, describes an equilibrium in which subjects make mistakes in implementing their best replies and assume other players do so as well. One specification of this model fits the experimental data best, among the models we test, and is able to account for all the main features we observe in the data

Computational Issues in the Statistical Design and Analysis of Experimental Games

One goal of experimental economics is to provide data to identify models that best describe the behavior of experimental subjects and, more generally, human economic behavior. We discuss here what we think are the three main steps required to make experimental investigations of economic games as statistically informative as possible: finding the solution of the experimental game under the postulated equilibrium or other economic models, selecting from a potential class of experimental designs the optimal one for discriminating between those models, and choosing an optimal stopping rule that indicates when to stop sampling data and accept one model as the best explanation of the data. Each step can be computationally intensive. We offer an algorithmic presentation of the necessary computations in each of the three steps and illustrate these procedures by examples from our research on learning models in experimental games with incomplete information. These three steps of experimental design and analysis are not limited to experimental games, but the computational burden of implementing these algorithms in other experimental environments - for example, market experiments - requires further considerations with which we have not dealt

Budget Processes: Theory and Experimental Evidence

This paper studies budget processes, both theoretically and experimentally. We compare the outcomes of bottom-up and top-down budget processes. It is often presumed that a top-down budget process leads to a smaller overall budget than a bottom-up budget process. Ferejohn and Krehbiel (1987) showed theoretically that this need not be the case. We test experimentally the theoretical predictions of their work. The evidence from these experiments lends strong support to their theory, both at the aggregate and the individual subject level

A Statistical Theory of Equilibrium in Games

This paper describes a statistical model of equiliobrium behaviour in games, which we call Quantal Response Equilibrium (QRE). The key feature of the equilibrium is that individuals do not always play responses to the strategies of their opponents, but play better strategies with higher probability than worse strategies. we illustrate several different applications of this approach, and establish a number of theoretical properties of this equilibrium concept. We also demonstrate an equililance between this equilibrium notion and Bayesian games derived from games of complete information with perturbed payoff