On-the-job leisure is a pervasive feature of the modern workplace. We studied its impact on work performance in a laboratory experiment by either allowing or restricting Internet access. We used a 2 × 2 experimental design in which subjects completing real-effort work tasks could earn cash according to either individual- or team-production incentive schemes. Under team pay, production levels were significantly lower when Internet browsing was available than when it was not. Under individual pay, however, no differences in production levels were observed between the treatment in which Internet was available and the treatment in which it was not. In line with standard incentive theory, individual pay outperformed team pay across all periods of the experiment when Internet browsing was available. This was not the case, however, when Internet browsing was unavailable. These results demonstrate that the integration of on-the-job leisure activities into an experimental labor design is crucial for uncovering incentive effects.

We compare behavior in modified dictator games with and without role uncertainty. Subjects choose between a selfish action, a costly surplus creating action (altruistic behavior) and a costly surplus destroying action (spiteful behavior). While costly surplus creating actions are the most frequent under role uncertainty (64%), selfish actions become the most frequent without role uncertainty (69%). Also, the frequency of surplus destroying choices is negligible with role uncertainty (1%) but not so without it (11%). A classification of subjects into four different types of interdependent preferences (Selfish, Social Welfare maximizing, Inequity Averse and Competitive) shows that the use of role uncertainty overestimates the prevalence of Social Welfare maximizing preferences in the subject population (from 74% with role uncertainty to 21% without it) and underestimates Selfish and Inequity Averse preferences. An additional treatment, in which subjects undertake an understanding test before participating in the experiment with role uncertainty, shows that the vast majority of subjects (93%) correctly understand the payoff mechanism with role uncertainty, but yet surplus creating actions were most frequent. Our results warn against the use of role uncertainty in experiments that aim to measure the prevalence of interdependent preferences.

Several papers have documented that when subjects play with standard laboratory “endowments” they make less self-interested choices than when they use money they have either earned through a laboratory task or brought from outside the lab. In the context of a charitable giving experiment we decompose this into two common artifacts of the laboratory: the intangibility of money (or experimental currency units) promised on a computer screen relative to cash in hand, and the distinct treatment of random “windfall” gains relative to earned money. While both effects are found to be significant in non-parametric tests, the former effect, which has been neglected in previous studies, has a stronger impact on total donations, while the latter effect has a greater impact on the probability of donating. These results have clear implications for experimental design, and also suggest that the availability of more abstract payment methods may increase other-regarding behavior in the field.

We investigate whether piece-rate and competitive incentives affect creativity, and if so, how the incentive effect depends on the form of the incentives. We find that while both piece-rate and competitive incentives lead to greater effort relative to a base-line with no incentives, neither type of incentives improve creativity relative to the base-line. More interestingly, we find that competitive incentives are in fact counter-productive in that they reduce creativity relative to base-line condition. In line with previous literature, we find that competitive conditions affect men and women differently: whereas women perform worse under competition than the base-line condition, men do not.

Truthful revelation is a dominant strategy in both English (oral ascending bid) and second-price sealed-bid private-values auctions. Controlled observations of English auctions are largely consistent with the dominant strategy prediction, but laboratory second-price auctions exhibit substantial and persistent overbidding, even with prior experience. However, the experience of having bid in an English auction has a significant learning effect, moving bidding in subsequent second-price auctions closer to the dominant strategy. I explore two treatments isolating facets of the lessons learned from English auction participation, leading me to the following conclusions. Part of the lesson carried over appears to be considering prices one-by-one, but most of it appears to be a crude awareness that overbidding leads to losses. A claim that English auction experience teaches subjects to recognize the dominant strategy in second-price auctions seems overly optimistic. I introduce a nonparametric technique to test coefficient restrictions when the assumption of normally distributed errors is untenable.

In this paper we use experimental data from rural Cameroon to quantify the effect of social distance on trust and altruism. Our measure of social distance is relevant to everyday economic interactions: subjects in a Trust Game play with fellow villagers or with someone from a different village. We find that significantly more money is sent when the players are from the same village. Other factors that influence transfers at least as much as the same-village effect are gender, education and membership of rotating credit groups. To test whether Senders are motivated by altruism, they also play a Triple Dictator Game. Senders transfer significantly more money on average in the Trust Game than in the Triple Dictator Game. However, there is also a social distance effect in the Triple Dictator Game. Results from a Risk Game suggest that Trust Game transfers are uncorrelated with attitudes to risk.

We measure the other-regarding behavior in samples from three related populations in the upper Midwest of the United States: college students, non-student adults from the community surrounding the college, and adult trainee truckers in a residential training program. The use of typical experimental economics recruitment procedures made the first two groups substantially self-selected. Because the context reduced the opportunity cost of participating dramatically, 91 % of the adult trainees solicited participated, leaving little scope for self-selection in this sample. We find no differences in the elicited other-regarding preferences between the self-selected adults and the adult trainees, suggesting that selection is unlikely to bias inferences about the prevalence of other-regarding preferences among non-student adult subjects. Our data also reject the more specific hypothesis that approval-seeking subjects are the ones most likely to select into experiments. Finally, we observe a large difference between self-selected college students and self-selected adults: the students appear considerably less pro-social.

Smith et al. (Econometrica 56(5):1119, 1988) reported large bubbles and crashes in experimental asset markets, a result that has been replicated many times. Here we test whether the occurrence of bubbles depends on the experimental subjects’ cognitive sophistication. In a two-part experiment, we first run a battery of tests to assess the subjects’ cognitive sophistication and classify them into low or high levels. We then invite them separately to two asset market experiments populated only by subjects with either low or high cognitive sophistication. We observe classic bubble and crash patterns in markets populated by subjects with low levels of cognitive sophistication. Yet, no bubbles or crashes are observed with our sophisticated subjects, indicating that cognitive sophistication of the experimental market participants has a strong impact on price efficiency.

Anecdotal evidence suggests that intermediaries are ubiquitous in corrupt activities; however, empirical evidence on their role as facilitators of corrupt transactions is scarce. This paper asks whether intermediaries facilitate corruption by reducing the moral or psychological costs of possible bribers and bribees. We designed bribery lab experiment that simulates petty corruption transactions between private citizens and public officials. The experimental data confirm that intermediaries lower the moral costs of citizens and officials and, thus, increase corruption. Our results have implications with respect to possible anti-corruption policies targeting the legitimacy of the use of intermediaries for the provision of government services.

Demands in the Ultimatum Game in its traditional form with one proposer and one responder are compared with demands in an Ultimatum Game with responder competition. In this modified form one proposer faces three responders who can accept or reject the split of the pie. Initial demands in both ultimatum games are quite similar, however in the course of the experiment, demands in the ultimatum game with responder competition are significantly higher than in the traditional case with repeated random matching. Individual round-to-round changes of choices that are consistent with directional learning are the driving forces behind the differences between the two learning curves and cannot be tracked by an adjustment process in response to accumulated reinforcements. The importance of combining reinforcement and directional learning is addressed. Moreover, learning transfer between the two ultimatum games is analyzed.

In 1988 Smith, Suchanek, and Williams (henceforth SSW) introduced a very influential model to test the efficiency of experimental asset markets. They and many subsequent studies observe that bubbles are robust to many treatment changes. Instead, bubbles are avoided only when subjects are experienced in the same setting, when the dividend-process is experienced by subjects beforehand, or when the fundamental value-process (FV) is presented in a well understandable context to reduce subjects’ confusion. We extend this line of research and show that even marginal changes in the experimental instructions/procedure can eliminate bubbles in the SSW-model. In particular, we show that mispricing is significantly reduced and overvaluation is eliminated completely (i) when the fundamental value process is displayed in a graph instead of a table or (ii) when subjects are asked about the current fundamental value at the beginning of each period. From a questionnaire conducted at the end of the experiment we infer that these treatment changes help to improve subjects’ understanding of the FV-process. We conclude that all bubble reducing factors have one common feature: they allow subjects to understand the non-intuitive declining FV-process of the SSW-model better and thus reduce subjects’ confusion about the FV-process.

There is an odd contradiction about much of the empirical (experimental) literature: The data is analysed using statistical tools which presuppose that there is some noise or randomness in the data, but the source and possible nature of the noise are rarely explicitly discussed. This paper argues that the noise should be brought out into the open, and its nature and implications openly discussed. Whether the statistical analysis involves testing or estimation, the analysis inevitably is built upon some assumed stochastic structure to the noise. Different assumptions justify different analyses, which means that the appropriate type of analysis depends crucially on the stochastic nature of the noise. This paper explores such issues and argues that ignoring the noise can be dangerous.

This paper analyzes if men and women are expected to behave differently regarding altruism. Since the dictator game provides the most suitable design for studying altruism and generosity in the lab setting, we use a modified version to study the beliefs involved in the game. Our results are substantial: men and women are expected to behave differently. Moreover, while women believe that women are more generous, men consider that women are as generous as men.

Many experiments have demonstrated the power of norm enforcement— peer monitoring and punishment—to maintain, or even increase, contributions in social dilemma settings, but little is known about the underlying norms that monitors use to make punishment decisions, either within or across groups. Using a large sample of experimental data, we empirically recover the set of norms used most often by monitors and show first that the decision to punish should be modeled separately from the decision of how much to punish. Second, we show that absolute norms often fit the data better than the group average norm often assumed in related work. Third, we find that different norms seem to influence the decisions about punishing violators inside and outside one's own group.

Previous studies have shown that simply knowing one player moves first can affect behavior in games, even when the first-mover's moves are known to be unobservable. This observation violates the game-theoretic principle that timing of unobserved moves is irrelevant, but is consistent with virtual observability, a theory of how timing can matter without the ability to observe actions. However, this previous research only shows that timing matters in games where knowledge that one player moved first can help select that player's preferred equilibrium, presenting an alternative explanation to virtual observability. We extend this work by varying timing of unobservable moves in ultimatum bargaining games and “weak link” coordination games. In the latter, the equilibrium selection explanation does not predict any change in behavior due to timing differences. We find that timing without observability affects behavior in both games, but not substantially.

Recent research argues “betrayal aversion” leads many people to avoid risk more when a person, rather than nature, determines the outcome of uncertainty. However, past studies indicate that factors unrelated to betrayal aversion, such as loss aversion, could contribute to differences between treatments. Using a novel experiment design to isolate betrayal aversion, one that varies how strategic uncertainty is resolved, we provide rigorous evidence supporting the detrimental impact of betrayal aversion. The impact is substantial: holding fixed the probability of betrayal, the possibility of knowing that one has been betrayed reduces investment by about one-third. We suggest emotion-regulation underlies these results and helps to explain the importance of impersonal, institution-mediated exchange in promoting economic efficiency.

We suggest that overconfidence (conscious or unconscious) is motivated in part by strategic considerations, and test this experimentally. We find compelling supporting evidence in the behavior of participants who send and respond to others’ statements of confidence about how well they have scored on an IQ test. In two-player tournaments where the higher score wins, a player is very likely to choose to compete when he knows that his own stated confidence is higher than the other player’s, but rarely when the reverse is true. Consistent with this behavior, stated confidence is inflated by males when deterrence is strategically optimal and is instead deflated (by males and females) when luring (encouraging entry) is strategically optimal. This behavior is consistent with the equilibrium of the corresponding signaling game. Overconfident statements are used in environments that seem familiar, and we present evidence that suggests that this can occur on an unconscious level.

Bayes’ statistical rule remains the status quo for modeling belief updating in both normative and descriptive models of behavior under uncertainty. Some recent research has questioned the use of Bayes’ rule in descriptive models of behavior, presenting evidence that people overweight ‘good news’ relative to ‘bad news’ when updating ego-relevant beliefs. In this paper, we present experimental evidence testing whether this ‘good-news, bad-news’ effect is present in a financial decision making context (i.e. a domain that is important for understanding much economic decision making). We find no evidence of asymmetric updating in this domain. In contrast, in our experiment, belief updating is close to the Bayesian benchmark on average. However, we show that this average behavior masks substantial heterogeneity in individual updating behavior. We find no evidence in support of a sizeable subgroup of asymmetric updators.

We conduct a framed field experiment in rural Ethiopia to test the seminal hypothesis that insurance provision induces farmers to take greater, yet profitable, risks. Farmers participated in a game protocol in which they were asked to make a simple decision: whether or not to purchase fertilizer and if so, how many bags. The return to fertilizer was dependent on a stochastic weather draw made in each round of the game. In later rounds a random selection of farmers made this decision in the presence of a stylized weather-index insurance contract. Insurance was found to have some positive effect on fertilizer purchases. Purchases were also found to depend on the realization of the weather in the previous round. We explore the mechanisms of this relationship and find that it may be the result of both changes in wealth weather brings about, and changes in perceptions of the costs and benefits to fertilizer purchases.

Berg et al. (Games and Economic Behavior, 10, pp. 122-142, 1995) study trust and reciprocity in an investment setting. They find significant amounts of trust and reciprocity and conclude that trust is a guiding behavioral instinct (a “primitive” in their terminology). We modify the way information is presented to participants and, through a questionnaire, prompt strategic reasoning. To our surprise, none of our various treatments led to a reduction in the amount invested. Previously reported experimental results to the contrary did not survive replication. Our results suggest that those by Berg, Dickhaut, and McCabe are rather robust to changes in information presentation and strategic reasoning prompts. We discuss the implications of these findings.