Experimental Economics

We study self-selection into earning money in an honest or dishonest fashion based on individuals’ attitudes toward truthful reporting. We propose a decision-theoretic framework where individuals’ willingness to pay for honest earnings is determined by their (behavioral) lying costs. Our laboratory experiment identifies lying costs as the decisive factor causing self-selection into honest earning opportunities for individuals with high costs and into cheating opportunities for those prepared to misreport. Our experimental setup allows us to recover individual lying costs and their distribution in the population.

This paper provides a comparative-statics analysis of punishment in public-good experiments. We vary the effectiveness of punishment, that is, the factor by which punishment reduces the punished player’s income. The data show that contributions increase monotonically in punishment effectiveness. High effectiveness leads to near complete cooperation and welfare improvements. Below a certain threshold, however, punishment cannot prevent the decay of cooperation. In these cases, punishment opportunities reduce welfare. The results suggest that the experimenter’s choice of the punishment effectiveness is of great importance for the experimental outcome.

We use data from experiments on finitely repeated dilemma games with fixed matching to investigate the effect of different types of information on cooperation. The data come from 71 studies using the voluntary contributions paradigm, covering 122 data points, and from 18 studies on decision-making in oligopoly, covering another 50 data points. We find similar effects in the two sets of experimental games. We find that transparency about what everyone in a group earns reduces contributions to the public good, as well as the degree of collusion in oligopoly markets. In contrast, transparency about choices tends to lead to an increase in contributions and collusion, although the size of this effect varies somewhat between the two settings. Our results are potentially useful for policy making, because they provide guidance on the type of information to target in order to stimulate or limit cooperation.

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.

Bidding one’s value in a second-price, private-value auction is a weakly dominant solution (Vickrey in J Finance 16(1):8–37, 1961), but repeated experimental studies find more overbidding than underbidding. We propose a model of optimistically irrational bidders who understand that there are possible gains and losses associated with higher bids but who may overestimate the additional probability of winning and/or underestimate the potential losses when bidding above value. These bidders may fail to discover the dominant strategy—despite the fact that the dominant strategy only requires rationality from bidders—but respond in a common sense way to out-of-equilibrium outcomes. By varying the monetary consequences of losing money in experimental auctions we observe more overbidding when the cost to losing money is low, and less overbidding when the cost is high. Our findings lend themselves to models in which less than fully rational bidders respond systematically to out-of-equilibrium incentives, and we find that our model better fits the effects of our manipulations than most of the existing models we consider.

We examine motives for ‘overbidding’ in contests between individuals using a “two-headed” approach to decision-making. In “two-headed” contests, subject pairs send suggested bids and messages to a partner. Content analysis of the messages provides insight into an individual’s bidding motives. In addition, we elicit measures of preferences, beliefs, and impulsiveness. We find that beliefs about others’ bids and messages that emphasize winning (i.e., utility of winning) are the most robust predictors of ‘overbidding’. Our results suggest that analyzing communication provides a rich window into an individual’s thought process when making decisions, and can complement insights from elicited values from common decision tasks (Replication materials, including data, do files, and software, are available at https://sites.google.com/view/david-bruner/research ).

We examine behavior in a Coasian contracting game with incomplete information. Experimental subjects propose contracts, while automaton property right holders or “robot” players with uncertain preferences respond to those proposals. The most common pattern of proposals observed in these games results in too many agreements and, in some games, payoffs that are stochastically dominated by those resulting from rational proposals (which imply fewer agreements). In this sense, we observe a “winner's curse” similar to that observed in bidding games under incomplete information, such as the “common value auction” (Kagel, J.H. and Levin, D. (1986) American Economic Review. 76, 894–920) and the “takeover game” (Samuelson, W. and Bazerman, M.H. (1985) In Research in Experimental Economics, Vol. 3. JAI Press, Greenwich, pp. 105–137; Ball, S.B., Bazerman, M.H., and Carroll, J.S. (1990) Organizational Behavior and Human Decision Processes. 48, 1–22; Holt, C. and Sherman, R. (1994) American Economic Review. 84, 642–652). While the “naïve model” of behavior nicely predicts the winner's curse in those previous bidding games, it does not do so here. Instead, an alternative model we call the “guarantor model” explains the anomalous behavior best. Hence, we suggest this is a new variant of the winner's curse.

The work undertook is located between Public Economic Theory and Experimental Economics. The object of the thesis consists in analysing the aggregate behavior and the individual heterogeneity in a voluntary contribution game. The thesis defended here is that overcontribution in comparison to the Nash equilibrium of the game, can not be explained neither by judgement errors, nor by the information on the individual behaviour of the members in a one given group. The level of contribution observed remains nevertheless inferior to the one simulated using the E.W.A. learning model. The dissertation is composed of three parts and six chapters. The first chapter expresses the various theoretical mechanisms of production of a public good, while the second one presents an overview of the experimental literature using voluntary contribution mechanisms. The second part carries on the introduction of an interior solution in a public good game in order to distinguish an explanation of overcontribution in terms of mistakes or strategies. While chapter three presents the most important works in literature that use an interior solution, the fourth chapter constitutes a personal contribution consisting in an experiment with an interior optimum. Our main result is that individuals contribute a constant part of their social optimum and that overcontribution is not explained by error. We test then the simple learning model R.L. using the observed data on the aggregate level. This model predicts well the observed behaviour. The third part is composed of two experiments where the environment of players is modified. We introduce in chapter five promises as cheap talk and find that they increase contributions at the aggregate level. In chapter six, various conditions of information on individual contributions are tested. The parameter tested is the level of information on “neighbours” contributions given to players. One of the treatments presents full information about individual contributions of the members of the group, while this information is incomplete in the other treatments. Our results show that information has no effect on the level of contribution. We simulate then the EWA learning model both at the aggregate and the individual levels and compare the simulated data to the experimental one. These simulations predict a level of contribution that is higher that the one observed in the experiment.

Economists and psychologists have long argued the origin of wealth influences individual behavior. In a previous study (Cherry et al., 2005), we found the origin of endowment did not significantly affect behavior in linear public good games with summation contribution technology. In such games, however, both Nash behavior (everybody gives nothing) and social optimal behavior (everybody gives the entire endowment) call for symmetric levels of contributions. Results from this new study indicate that the origin of wealth might matter in more asymmetric situations, such as in a best-shot public good game with heterogeneous groups.