We investigate the effects of heterogeneity and incomplete information on aggregate contributions to a public good using the voluntary contribution mechanism. The non-linear laboratory environment has three-person groups as partners under varying conditions of information and communication. Bergstrom, Blum and Varian predict that increasing heterogeneity will have no effect on aggregate contributions in a no-communication environment. Ledyard conjectures a positive effect of incomplete information, a negative effect of heterogeneity, and a positive interaction of heterogeneity and incomplete information. We find that incomplete information has a small but significant negative effect. Heterogeneity has a positive effect on aggregate contributions, but its effects interact unexpectedly with communication. In a no-communication environment, heterogeneity in two dimensions (endowment and preferences) increases contributions substantially while heterogeneity in a single dimension (endowment or preferences) has little effect. In the communication environment we find the reverse. We also find a positive interaction between heterogeneity and incomplete information. Thus we reject the Bergstrom, Blume and Varian invariance result and provide mixed evidence on Ledyard's conjectures.

Controlled laboratory conditions using monetary incentives have been utilized in previous studies that examine individual discount rates, and researchers have found several apparently robust anomalies. We conjecture that subject behavior in these experiments may be affected by (uncontrolled) factors other than discount rates. We address some experimental design issues and report a new series of experiments designed to elicit individual discount rates. Our primary treatments include: (i) informing subjects of the annual and effective interest rates associated with alternative payment streams, and (ii) informing subjects of current market interest rates. We also test for the effect of real (vs. hypothetical) payments and for the effect of delaying both payment options (vs. offering an immediate payment option). The statistical analysis uses censored data techniques to account for the interactions between field and lab incentives. Each of the information treatments appears to reduce revealed discount rates. When both types of information are provided, annual rates in the interval of 15%—17.5% are revealed, whereas rates of 20%-25% are revealed in the control session. Each of the treatments also lowers the residual variance of subject responses.

This is an investigation into the design of a market-based process to replace NASA's current committee process for allocating Shuttle secondary payload resources (lockers, Watts and crew). The market-based process allocates budgets of tokens to NASA internal organizations that in turn use the budget to bid for priority for their middeck payloads. The scheduling algorithm selects payloads by priority class and maximizes the number of tokens bid to determine a manifest. The results of a number of controlled experiments show that such a system tends to allocate resources more efficiently by guiding participants to make resource and payload tradeoffs. Most participants were able to improve their position over NASA's current ranking system. Furthermore, those that are better off make large improvements while the few that do worse have relatively small losses.

The largest market in national economies is the labor market. Labor market contracting is characterized by job search, often from unknown wage offer distributions. This paper reports experimental tests of finite horizon models of job search in which the wage offer distribution is unknown. Theoretically-optimal search from an unknown wage offer distribution can have the seemingly paradoxical property that some offers will be accepted that are lower than other offers that will be rejected in the same period of the search horizon. Thus the reservation wage property (or lowest acceptable wage path) may not exist. This can occur because an offer that is a priori relatively high (“good news”) can imply that it is highly probable that search is from a favorable distribution, and such an offer can look unattractive when it is an a posteriori relatively low offer from a favorable distribution (“bad news”). This paper reports results from experimental treatments for search from unknown distributions in which the reservation wage property does exist and treatments in which it does not exist. We find that the consistency of search behavior with search theory reported in earlier papers is robust to the presence or absence of the reservation wage property and to whether the draws come from known or unknown distributions.

This paper reports an experiment to determine whether subjects will learn to stop using a strictly dominated strategy that can be an above average reply. It is difficult to find an experimental design that eliminates the play of the strictly dominated strategy completely. The least effective treatment used money to motivate behavior directly. The most effective treatment used a binary-lottery with money prizes to induce preferences, but even this treatment required giving subjects plenty of experience. Doing so reduced the play of the strictly dominated strategy to around 10 percent by the end of a session. There is no evidence for the explosive cycling needed to make the strictly dominated strategy an above average reply.

A number of studies demonstrate that individual choice can be influenced by alternatives which should be irrelevant according to standard choice theory. In these studies it has been observed that introducing a decoy option, which is either asymmetrically dominated by a target option or which makes the target a compromise, increases the likelihood of choosing the target. A common feature of earlier research on decoy effects is the use of hypothetical choice tasks. The aim of this paper is to investigate decoy effects in a properly controlled experiment where subjects are given real incentives. Here, monetary gambles are used as alternatives. The results demonstrate that decoy effects persist despite the use of real incentives.

This paper constructs a structural model for behavior in expeiments where subjects play a simple coordination game repeatedly under a rotating partner scheme. The model assumes subjects’ actions are stochastic best responses to beliefs about opponents’ choices, and these beliefs update as subjects observe actual choices during the experiment. The model accounts for heterogeneity across subjects by regarding prior beliefs as random effects and estimating their distribution. Maximum likelihood estimates from experimental data suggest that distributions of initial beliefs vary across games, but in all games studied imply a convergence dynamic toward risk-dominant equilibrium.

In an experimental evolutionary game framework we investigate whether subjects end up in a socially efficient state. We examine two games, a game where the socially efficient state is also an equilibrium and a game which has no equilibrium in pure strategies at all. Furthermore, we distinguish between a situation in which the subjects are completely informed about the payoff function and a situation in which they are incompletely informed. We observe that subjects spend the greater part of the time at or near the efficient state. If the efficient state is an equilibrium, they spend more time there than otherwise. Furthermore, incomplete information increases the time spent at the efficient state.

In experiments with two-person sequential games we analyze whether responses to favorable and unfavorable actions depend on the elicitation procedure. In our “hot” treatment the second player responds to the first player's observed action while in our “cold” treatment we follow the “strategy method” and have the second player decide on a contingent action for each and every possible first player move, without first observing this move. Our analysis centers on the degree to which subjects deviate from the maximization of their pecuniary rewards, as a response to others’ actions. Our results show no difference in behavior between the two treatments. We also find evidence of the stability of subjects’ preferences with respect to their behavior over time and to the consistency of their choices as first and second mover.

One important determinant of voluntary contributions to public goods is the value of the public good relative to that of the forgone private good. Isaac, Walker and Thomas (1984) formalized this relation in the Marginal Per Capita Return (MPCR) and demonstrated its influence on the provision of linear public goods. This paper develops a parallel concept, in the context of a threshold public good, the Step Return (SR). After providing a meta-analysis of the effect of SR in previous experiments, we compare contributions in threshold public goods games with low, medium and high SRs. Results show that subjects respond to the SR in this setting just as they respond to the MPCR in the linear public goods setting: higher SRs lead to more contributions.

The study investigates collusion-nonfacilitating features of one-sided auctions. We report the results of oral nondescending bid auction experiments in which the strict bid improvement rule was absent, and compare them with the results of sealed bid auction experiments. In the sealed bid experiments the outcomes converged to the competitive equilibrium. In the oral auctions, collusive outcomes emerged and were sustained with bidders using bid matching strategies. We conclude that oral auctions provide opportunities for tacit coordination and collusion enforcement that do not exist under the sealed bid. Therefore, the strict bid improvement rule becomes critical for breaking collusion.

We propose a simple adaptive learning model to study behavior in the call market. The laboratory environment features buyers and sellers who receive a new random value or cost in each period, so they must learn a strategy that maps these random draws into bids or asks. We focus on buyers’ adjustment of the “mark-down” ratio of bids relative to private value and sellers’ adjustment of the corresponding “mark-up” ratio of asks relative to private cost. The learning model involves partial adjustment of these ratios towards the ex post optimum each period. The model explains a substantial proportion of the variation in traders’ strategies. Parameter estimates indicate strong recency effects and negligible autonomous trend, but strongly asymmetric response to different kinds of ex post error. The asymmetry is only slightly attenuated in “observational learning” from other traders’ ex post errors. Simulations show that the model can account for the main systematic deviations from equilibrium predictions observed in this market institution and environment.