Subgame perfection in ultimatum bargaining trees

In typical experiments on ultimatum bargaining, the game is described verbally and the majority of subjects deviate from subgame-perfect behavior. Proposers typically offer significantly more than the minimum possible and Responders reject “unfair” offers. In this work, we show that when the ultimatum bargaining game is presented as an abstract game tree, the vast majority of behavior is consistent with individualistic preferences and subgame-perfection. This finding raises doubts about theories that ignore the potential influence of social context and experiments that do not control for social context.     

Information acquisition in the ultimatum game: An experimental study

We experimentally investigate if free information disadvantages a player relative to when information is unavailable. We study an Ultimatum game where the Proposer, before making an offer, can obtain free information about the Responder's minimum acceptable offer. Theoretically, the Proposer should obtain the information and play a best reply to the Responder's minimum acceptable offer. Thus the Responder should get the largest share of the surplus. We find that an increasing number of Proposers become informed over time. Moreover, the proportion of Proposers who use the information to maximize money earnings increases over time. The majority of information-acquiring Proposers, however, refuse to offer more than one-half and play a best reply only to Responders who accept offers of one-half or less. This, together with a substantial proportion of Proposers who choose to remain uninformed, means that the availability of free information backfires for Proposers only by a little. Electronic Supplementary Material Supplementary material is available in the online version of this article at . JEL Classification C70, D63, D80     

Advice and behavior in intergenerational ultimatum games: An experimental approach

In the real world, when people play a game, they often receive advice from those that have played it before them. Such advice can facilitate the creation of a convention of behavior. This paper studies the impact of advice on the behavior subjects who engage in a non-overlapping generational Ultimatum game where after a subject plays he is replaced by another subject to whom he can offer advice.Our results document the fact that allowing advice fosters the creation of a convention of behavior in Ultimatum games. In addition, by reading the advice offered we conclude that arguments of fairness are rarely used to justify the offers of Senders but are relied upon to justify rejections by Receivers.     

Indicative bidding: An experimental analysis

Indicative bidding is a practice commonly used in sales of complex and very expensive assets. Theoretical analysis shows that efficient entry is not guaranteed under indicative bidding, since there is no equilibrium in which more qualified bidders are more likely to be selected for the final sale. Furthermore, there exist alternative bid procedures that, in theory at least, guarantee 100% efficiency and higher revenue for the seller. We employ experiments to compare actual performance between indicative bidding and one of these alternative procedures. The data shows that indicative bidding performs as well as the alternative procedure in terms of entry efficiency, while having other characteristics that favor it over the alternative procedure. Our results provide an explanation for the widespread use of indicative bidding despite the potential problem identified in the equilibrium analysis.     

An experimental analysis of the bandit problem

Summary.  We investigate, in an experimental setting, the behavior of single decision makers who at discrete time intervals over an “infinite” horizon may choose one action from a set of possible actions where this set is constant over time, i.e. a bandit problem. Two bandit environments are examined, one in which the predicted behavior should always be myopic (the two-armed bandit) and the other in which the predicted behavior should never be myopic (the one-armed bandit). We also investigate the comparative static predictions as the underlying parameters of the bandit environments are changed. The aggregate results show that the behavior in the two bandit environments are quantitatively different and in the direction of the theoretical predictions. Received: October, 27, 1994; revised version February 27, 1996     

An advantage of the bargaining set over the core

An example of a market game is described for which the bargaining set seems to be intuitively more acceptable than the (nonempty) core. It also yields more insight into the nature of the competition that may exist among the traders.     

An admissible set occurring in various bargaining situations

Given a set of alternatives S and a binary relation M on S the admissible set of the pair (S, M) is defined to be the set of maximal elements with respect to the transitive closure of M. It is shown that existing solutions in game theory and mathematical economics are special cases of this concept (they are admissible sets of a natural S and M). These include the core of an n-person cooperative game, Nash equilibria of a noncooperative game, and the max-min solution of a two-person zero sum game. The competitive equilibrium prices of a finite exchange economy are always contained in its admissible set. Special general properties of the admissible set are discussed. These include existence, stability, and a stochastic dynamic process which leads to outcomes in the admissible set with high probability.     

Corruption and culture: An experimental analysis

Why do some people choose corruption over honesty and others not? Do the social norms and values prevailing in the societies in which they grew up affect their decisions? In 2005, we conducted a bribery experiment and found that, among undergraduates, we could predict who would act corruptly with reference to the level of corruption in their home country. Among graduate students we could not. In 2007, we replicated our result and also found that time spent in the UK was associated with a decline in the propensity to bribe, although this does not explain our inability to predict graduate behaviour. We conclude that, while corruption may, in part, be a cultural phenomenon, individuals should not be prejudged with reference to their country of origin.     

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.     

Inter-gender interaction and communication in ultimatum games

In this article, we focus on bargaining within male–female pairs, the most pervasive partnership in humankind. We analyse data from an ultimatum game played by Greek participants. Parallel to this, we introduce a one-way communication protocol according to which the responders can send short messages to the receivers, after making their decisions. The analysis shows that gender and message effects exist and males are more effective bargainers.     

How individuals choose health insurance: An experimental analysis

An individual choosing a health insurance policy faces a complex decision environment where a large set of alternatives differ on a variety of dimensions. There is uncertainty and the choice is repeated at least once a year. We study decisions and decision strategies in a laboratory experiment where we create a controlled environment that closely mirrors this setting. We use an electronic information board that allows to carefully monitor the individual's decision strategy. The number of alternatives, switching costs, and the speed at which health deteriorates are varied across treatments. We find that most subjects' search is based more on attributes than on policies. Moreover, we find that an increase in the number of alternatives increases decision-making time; makes subjects consider a lower fraction of the available information; makes it more likely that subjects will switch; and decreases the quality of their decisions. The introduction of positive costs of switching makes people switch less often but improves the quality of their decisions. Finally, if health deteriorates only gradually, individuals tend to stick to their current policy too long.     

Corruption in public service delivery: An experimental analysis

To improve our understanding of corruption in service delivery, we use a newly designed game that allows us to investigate the effects of the institutional environment on the behavior of service providers and their monitors. We focus on the effect of four different factors: whether monitors are accountable to the service recipients, the degree of observability of service providers’ effort, the providers’ wages and the providers’ professional norms. In accordance with theory, we find that service providers perform better when monitors are elected by service recipients and when their effort is more easily observed. However, there is only weak evidence that service providers perform better when paid more. Monitors are more vigilant when elected and when service providers are paid more. Playing the game with Ethiopian nursing students, we also find that those with greater exposure to the Ethiopian public health sector perform less well, either as provider or as monitor, when the experiment is framed as a public health provision scenario, suggesting that experience and norms affect behavior.     

Competitive bargaining equilibrium

In a simple exchange economy we propose a bargaining procedure that leads to a Walrasian outcome as the agents become increasingly patient. The competitive outcome therefore obtains even if agents have market power and are not price-takers. Moreover, where in other bargaining protocols the final outcome depends on bargaining power or relative impatience, the outcome here is determinate and depends only on preferences and endowments. Our bargaining procedure involves bargaining over prices and maximum quantity constraints, and it guarantees convergence to a Walrasian outcome for any standard exchange economy. In contrast, without quantity constraints we show that equilibrium is generically inefficient.     

Incentive effects and overcrowding in tournaments: An experimental analysis

This study reports experiments that examine outcomes when agents choose between a payment scheme that rewards based on absolute performance (i.e., piece rate) and a scheme that rewards based on relative performance (i.e., a tournament). Holding total payments in the tournament constant, performance is higher when the tournament option is winner-take-all compared to a graduated tournament (i.e., second and third-place performers also receive a payment). Performance is higher in the winner-take all tournaments even among participants that choose the piece-rate option. While there is a modest amount of overcrowding, there are no significant differences in overcrowding across conditions. Entry rates into the tournament and the relative ability of tournament entrants (compared to non-entrants in the same condition) are higher in the graduated tournament condition than the winner-take-all conditions. Consequently, the winner-take-all tournament is more efficient than the graduated tournament (incentive effects are stronger and the overcrowding is about the same), but the graduated tournament provides a more effective mechanism to identify the most capable performer in a talent pool. Electronic Supplementary Material Supplementary material is available in the online version of this article at . JEL Classification D8 · J3 · L2     

An experimental analysis of cooperation and productivity in the trust game

In the standard trust game the surplus is increased by the risk taking first mover while cooperation by the second mover is a one-to-one transfer. This paper reports results from experiments in which the reverse holds; the first mover’s risky trust is not productive and the second mover’s cooperation is productive. This subtle difference significantly lowers the likelihood of trust but increases the likelihood of cooperation conditional on trust. Evidence is presented that the change in trust is consistent with first movers failing to anticipate the later result. Drawing upon the analogy that the trust game represents a model of exchange, the results suggest that markets should be organized so that the buyer moves first and not the seller as in the original trust game.

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Demand bargaining in legislatures

We analyze a pure bargaining problem when decisions require simple majority and self interested players make unilateral demands. In contrast to the case where proposals consist of complete sharing profiles, this content of proposals prevents implicit side-payments inside the committee, and so non-discriminatory outcomes might be expected. We show that in some settings this is the case and the surplus is universally shared.     

Subgame-perfect implementation of bargaining solutions

We study house allocation problems introduced by L. Shapley and H. Scarf (1974, J. Math. Econ.1, 23–28). We prove that a mechanism (a social choice function) is individually rational, anonymous, strategy-proof, and nonbossy (but not necessarily Pareto efficient) if and only if it is either the core mechanism or the no-trade mechanism, where the no-trade mechanism is the one that selects the initial allocation for each profile of preferences. This result confirms the intuition that even if we are willing to accept inefficiency, there exists no interesting strategy-proof mechanism other than the core mechanism. Journal of Economic Literature Classification Numbers: C71, C78, D71, D78, D89.     

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.