Behavioral economics has grown significantly in importance and prevalence within the economics profession over the last couple of decades. Most economics departments now include researchers conducting behavioral research, and most economics journals regularly publish behavioral work.

Behavioral economics is generally defined as using evidence and constructs from neighboring social sciences, especially about limits on computation, willpower, and self-interest, to inform economic analysis (e.g., Camerer and Loewenstein, 2003). While many of these constructs come from psychology, other social sciences have much to contribute as well (see Weber and Dawes, 2005). For instance, anthropological research has provided important insights into the understanding of how social institutions and interactions shape strategic behavior (see Henrich et al., 2001).

We conducted the first randomized controlled field experiment of an Internet reputation mechanism. A high-reputation, established eBay dealer sold matched pairs of lots— batches of vintage postcards—under his regular identity and under new seller identities (also operated by him). As predicted, the established identity fared better. The difference in buyers’ willingness-to-pay was 8.1% of the selling price. A subsidiary experiment followed the same format, but compared sales by relatively new sellers with and without negative feedback. Surprisingly, one or two negative feedbacks for our new sellers did not affect buyers’ willingness-to-pay.

There is evidence that risk-taking behavior is influenced by prior monetary gains and losses. When endowed with house money, people become more risk taking. This paper is the first to report a house money effect in a dynamic, financial setting. Using an experimental method, we compare market outcomes across sessions that differ in the level of cash endowment (low and high). Our experimental results provide support for a house money effect. Traders’ bids, price predictions, and market prices are influenced by the amount of money that is provided prior to trading. However, dynamic behavior is difficult to interpret due to conflicting influences.

We present an experiment designed to separate the two commonplace explanations for behavior in ultimatum games—subjects’ concern for fairness versus the failure of subgame perfection as an equilibrium refinement. We employ a tournament structure of the bargaining interaction to eliminate the potential for fairness to influence behavior. Comparing the results of the tournament game with two control treatments affords us a clean test of subgame perfection as well as a measure fairness-induced play. We find after 10 iterations of play that about half of all non-subgame-perfect demands are due to fairness, and the rest to imperfect learning. However, as suggested by models of learning, we also confirm that the ultimatum game presents an especially difficult environment for learning subgame perfection.

We consider a sequential two-party bargaining game with uncertain information transmission. When the first mover states her demand she does only know the probability with which the second mover will be informed about it. The informed second mover can either accept or reject the offer and payoffs are determined as in the ultimatum game. Otherwise the uninformed second mover states his own demand and payoffs are determined as in the Nash demand game. In the experiment we vary the commonly known probability of information transmission. Our main finding is that first movers’ and uninformed second movers’ demands adjust to this probability as qualitatively predicted, that is, first movers’ (uninformed second movers’) demands are lower (higher) the lower the probability of information transmission.

What motivates people to trust and be trustworthy? Is trust solely “calculative,” based on the expectation of trustworthiness, and trustworthiness only reciprocity? Employing a within-subject design, we run investment and dictator game experiments in Russia, South Africa and the United States. Additionally, we measured risk preferences and expectations of return. Expectations of return account for most of the variance in trust, but unconditional kindness also matters. Variance in trustworthiness is mainly accounted for by unconditional kindness, while reciprocity plays a comparatively small role. There exists some heterogeneity in motivation but people behave surprisingly similarly in the three countries studied.

This paper contributes to the ongoing methodological debate on context-free versus in-context presentation of experimental tasks. We report an experiment using the paradigm of a bribery experiment. In one condition, the task is presented in a typical bribery context, the other one uses abstract wording. Though the underlying context is heavily loaded with negative ethical preconceptions, we do not find significant differences with our 18 independent observations per treatment. We conjecture that the experimental design transmits the essential features of a bribery situation already with neutral framing, such that the presentation does not add substantially to subjects’ interpretation of the task.

We run an experiment where 97 subjects could retrieve records of completed past auctions before placing their bids in current one-bid, two-bid, and auction-selection games. Each subject was asked to participate in 3 current auctions; but could retrieve up to 60 records of completed (past) auctions. The results reveal a positive relation between the payoffs earned by the subjects and their history-inspection effort. Subjects act as if responding to the average bidding-ratios of the winners in the samples that they have retrieved. They apply intuitive signal-dependent stopping rules like “sample until observing a winner-value close to my won” or “find a close winner-value and try one more history” when sampling the databases. History-inspection directs bidders with relatively high private-valuations to moderate bidding which increases their realized payoffs. (JEL C9 D4 D8)

Most studies that compare individual and group behavior neglect the in-group decision making process. This paper explores the decision making process within groups in a strategic setting: a two player power-to-take experiment. Discussions preceding group decisions are video taped and analyzed. We find the following: (1) no impact of the group setting as such on individual behavior; (2) heterogeneity of individual types; (3) perceptions of fairness are hardly discussed and are prone to the self-serving bias; (4) groups ignore the decision rule of other groups and typically view them as if they were single agents. (5) We also show that to explain group outcomes two factors have to be taken into account that are often neglected: the distribution of individual types over groups and the decision rules that groups use to arrive at their decision.

In most experimental studies of tax evasion, participants are instructed that they may report any amount of income from zero up to the amount they actually earned or received. This amounts to an invitation to gamble. In contrast, real-world tax authorities unambiguously demand compliance. We develop two new settings for conducting tax experiments. Both involve an explicit demand for compliance. Thus, we can determine whether knowing that the experimental authority would regard evasion as wrongful disobedience will influence compliance decisions. We demonstrate that simply telling people that they are required to pay a “participation fee” analogous to a tax produces remarkably high compliance rates and less sensitivity to changes in economic variables than in the earlier experimental literature using invitation-to-gamble language. This suggests that many people pay taxes despite the financial attraction of non-compliance because they are strongly inclined towards obeying authority. Furthermore, we show that giving participants a week to make their reporting decisions at home without an authority figure physically present overcomes the inclination to obey for some people, significantly lowering compliance rates. However, the majority still complies, even after the audit rate falls from 25% to 1%, which would make noncompliance extremely attractive if it were viewed only as a simple matter of risk and expected return.

Both mainstream economics and its critics have focused on models of individual rational agents even though most important decisions are made by small groups. Little systematic work has been done to study the behavior of small groups as decision-making agents in markets and other strategic games. This may limit the relevance of both economics and its critics to the objective of developing an understanding of how most important decisions are made. In order to gain some insight into this issue, this paper compares group and individual economic behavior. The objective of the research is to learn whether there are systematic differences between decisions made by groups and individual agents in market environments characterized by risky outcomes. A quantitative measure of deviation from minimally-rational decisions is used to compare group and individual behavior in common value auctions.

This paper investigates the development of conventions of trust in what we call intergenerational games, i.e., games played by a sequence of non-overplapping agents, who pass on advice on how to play the game across adjacent generations of players. Using the trust game of Berg et al. (1995) as our experimental decision problem, advice seems to decrease the amount of trust that evolves when this game in played in an inter-generational manner in that it decreases the amount of money sent from Senders to Returners. Ironically, advice increases trustworthiness in that Returners tend to send more back. Further, subjects appear to follows conventions of reciprocity in that they tend to Send more if they think the Returners acted in a “kind” manner, where kind means the Sender sent more money than the receiver expected. Finally, while we find a causal relationship running from trustworthiness to trust, the opposite can not be established. We note that many of our results can only be achieved using the tools offered by inter-generational games. The inter-generational advice offered provides information not available when games are played in their static form. Combining that information with elicited beliefs of the Senders and Returners adds even more information that can be used to investigate the motives that subjects have for doing what they do.

Several non-experimental studies claim that heterogeneity among individuals reduces trust. A few experimental studies have examined the effects of naturally-occurring differences among subjects on trusting behavior, and in contrast, most have not supported these claims. We adopt a novel approach by inducing heterogeneity among subjects in a canonical trust experiment. We accomplish this by varying the show-up payments given to subjects for participating in the experiment. We find that this induced inequality does not consistently affect first- or second-mover behavior in the classic trust game in the manner predicted by either previous theoretical work or empirical studies of survey-based measures of trust. Further, the effect of inequality on trust, in terms of both sign and significance, depends on whether show-up payments are awarded publicly or privately.

We study a class of trust-based cooperation dilemmas that evolve in continuous time. Characteristic of these dilemmas is that as long as all n players continue to cooperate, their payoffs increase monotonically over time. Simultaneously, the temptation to defect increases too, as the first player to defect terminates the interaction and receives the present value of the payoff function whereas each of the other n — 1 players only receives a proportion δ (0 < δ < 1) of the defecting player's payoff. We introduce a novel experimental institution that we call the Real-Time Trust Game (RTTG) to examine this class of interactions. We then report the results from an iterated RTTG in which the values of n and δ are varied in a between-subjects design. In all conditions, cooperation breaks down in the population over iterations of the game. The rate of breakdown sharply increases as n increases and more slowly decreases as δ increases.

Policies such as the SEC's Fair Disclosure Rule, and technologies such as SEC EDGAR, aim to disseminate corporate disclosures to a wider audience of investors in risky assets. In this study, we adopt an experimental approach to measure whether this wider disclosure is beneficial to these investors. Price-clearing equilibrium models based on utility maximization and non-revealing and fully-revealing prices predict that in a pure exchange economy, an arbitrary trader would prefer that no investors are informed rather than all are informed; non-revealing theory further predicts that an arbitrary trader would prefer a situation in which all traders are informed rather than half the traders are informed. These predictions can be summarized as “None > All > Half”. A laboratory study was conducted to test these predictions. Where previous studies have largely focused on information dissemination and its effects on equilibrium price and insider profits, we focus instead on traders’ expected utility, as measured by their preferences for markets in which none, half, or all traders are informed. Our experimental result contradicts the prediction and indicates “Half > None > All”, i.e. subjects favor a situation where a random half is informed. The implication is that in addition to testing predictions of price equilibrium, experiments should also be used to verify analytical welfare predictions of expected utility under different policy choices.

We report the results of experiments conducted over the internet between two different laboratories. Each subject at one site is matched with a subject at another site in a trust game experiment. We investigate whether subjects believe they are really matched with another person, and suggest a methodology for ensuring that subjects’ beliefs are accurate. Results show that skepticism can lead to misleading results. If subjects do not believe they are matched with a real person, they trust too much: i.e., they trust the experimenter rather than their partner.

We provide a simplified test to determine if choice data from a two-commodity consumption set satisfies the Generalized Axiom of Revealed Preference (GARP), and thus the preference or utility maximization hypothesis. We construct an algorithm for this test and illustrate its application on experimental choice data.

In recent work on non-cooperative network formation star-shaped networks play an important role. In a particular theoretical model of Bala and Goyal (2000) center-sponsored stars are the only strict Nash networks. In testing this theoretical model, Falk and Kosfeld (2003) do not find experimental evidence that players select the center-sponsored star. Based on a slight modification of Bala and Goyal's model, we design a network formation experiment in which, depending on link costs, periphery-sponsored stars and the empty network are the only strict Nash networks. We observe that almost all groups not only reach a strict Nash network once but also switch the center player in periphery-sponsored stars several times. The main innovation in our experiment is to use a continuous time framework which we believe to be a more realistic setting to study behavior in network formation situations and which makes coordination on stars much easier than simultaneous strategy adaptation in discrete time.

We examine the properties of a popular method for eliciting choices and values from experimental subjects, the multiple price list format. The main advantage of this format is that it is relatively transparent to subjects and provides simple incentives for truthful revelation. The main disadvantages are that it only elicits interval responses, and could be susceptible to framing effects. We consider extensions to address and evaluate these concerns. We conclude that although there are framing effects, they can be controlled for with a design that allows for them. We also find that the elicitation of risk attitudes is sensitive to procedures, subject pools, and the format of the multiple price list table, but that the qualitative findings that participants are generally risk averse is robust. The elicitation of discount rates appear less sensitive to details of the experimental design.