We investigate the role of endowment inequality in a local and global public goods setting with multiple group membership and examine the effect of temporal role reversal on cooperation decisions. Subjects can contribute to a global public good which benefits all subjects and two local public goods which benefit only subjects of either their own group or the group of the other endowment type. Endowment inequality per-se decreases contributions of subjects with a high endowment to the global public good, but increases cooperation of subjects with a low endowment on their local public good, thereby aggravating income disparities. Exogenously induced role reversal for several periods affects cooperation behavior of subjects with a high endowment positively and induces them to contribute more to the global good. Cooperation in unequal environments thus appears to be more stable when all parties have experienced the public goods game from the disadvantageous perspective.

Although households are responsible for many important decisions, they have rarely been the subject of economics experiments. We conduct a series of linked and incentivized experiments on decision-making, designed to see if the anomalies typically found in individual choice experiments are found when the subjects are couples from long-term relationships. Specifically we investigate the endowment effect, the compromise effect, asymmetric dominance and the ‘more is less’ phenomena. Comparing the results with two control groups (students and non-student individuals) we find broadly the same pattern of anomalies in individuals as we do in couples. Thus behavioural patterns that appear in individual choices appear relevant for decisions made by established couples.

Prior archival studies of analysts’ forecasts have found evidence for systematic underreaction, systematic overreaction, and systematic optimism bias. Easterwood and Nutt (1999) attempt to reconcile the conflicting evidence by testing the robustness of Abarbanell and Bernard's (1992) underreaction results to the nature of the information. Consistent with systematic optimism, forecasts are found to underreact to negative earnings information but overreact to positive information. However, Easterwood and Nutt are unable to distinguish between misreaction caused by incentives unique to analysts with misreaction caused by human decision bias that may be typical of investors. We address this issue by analyzing forecast reactions to positive versus negative information in the controlled experimental setting of Gillette, Stevens, Watts, and Williams (1999). The forecast data reveal systematic underreaction to both positive and negative information, and the underreaction is generally greater for positive information than negative information. This suggests that prior empirical evidence of forecast overreaction to positive information is unlikely to be attributable to human decision bias.

Temporary changes in biological state, such as hunger, can impact decision making differently for men and women. Food scarcity is correlated with a host of negative economic outcomes. Two explanations for this correlation are that hunger affects economic preferences directly or that hunger creates a mindset that focuses on scarcity management to the detriment of other decisions. To test these predictions, we conduct a lab-in-the-field experiment in a health screening clinic in Shanghai, recruiting participants who finish their annual physical exam either before or after they have eaten breakfast. We compare the hungry and sated groups on their risk, time and generosity preferences as well as their cognitive performance. Our results show that men and women respond to hunger in opposite directions, thus hunger reduces the gender gap in decision quality, risk aversion and cognitive performance, but creates one in generosity. Finally, we examine several biomarkers and find that higher blood lipid levels are correlated with greater choice inconsistency, risk aversion and generosity. We contribute to emerging insights on the biological foundations for economic preferences and outcomes.

Economists model self-control problems through time-inconsistent preferences. Empirical tests of these preferences largely rely on experimental elicitation using monetary rewards, with several recent studies failing to find present bias for money. In this paper, we compare estimates of present bias for money with estimates for healthy and unhealthy foods. In a within-subjects longitudinal experiment with 697 low-income Chinese high school students, we find strong present bias for both money and food, and that individual measures of present bias are moderately correlated across reward types. Our experimental measures of time preferences over both money and foods predict field behaviors including alcohol consumption and academic performance.

In a randomized field experiment, we show that a low-cost intervention, weekly email reminders, increases the weekly exercising frequency of gym members by 13%, with the effect being larger for class training (19%) than for free training (11%). We find that nearly all types of individuals benefit from the reminders (e.g., students, nonstudents, women, men, new members, recurring members), and this effect persists in a three-month posttreatment period. Furthermore, the increase in class visits is partly driven by an increase in the number of bookings of gym classes and a slight decrease in the share of bookings that are canceled. Limited attention and habit formation can best explain these results. In contrast to the increase in gym attendance, we do not find any effect on the duration and renewal of membership contracts.

Competition between groups is ubiquitous in social and economic life, and typically occurs between groups that are not created equal. Here we experimentally investigate the implications of this general observation on the unfolding of symmetric and asymmetric competition between groups that are either homogeneous or heterogeneous in the ability of their members to contribute to the success of the group. Our main finding is that relative to the benchmark case in which two homogeneous compete against each other, heterogeneity within groups per se has no discernable effect on competition, while introducing heterogeneity between groups leads to a significant intensification of conflict as well as increased volatility, thereby reducing earnings of contest participants and increasing inequality. We further find that heterogeneous groups share the labor much more equally than predicted by theory, and that in asymmetric contests group members change the way in which they condition their efforts on those of their peers. Implications for contest designers are discussed.

Two rationales have emerged for why individuals keep their promises: (a) an emotional commitment to keep actions and words consistent, a commitment rationale and (b) avoidance of guilt due to not meeting the expectations of the promisee, an expectations rationale. We propose a new dichotomy with clearer distinctions between rationales: (1) an internal consistency rationale, which is the desire to keep actions and words consistent regardless of others’ awareness of the promise and (2) a communication rationale, which captures all aspects of promise keeping that are associated with the promisee having learned of the promise, including but not limited to promisee expectations. Using an experiment that manipulates whether promises are delivered, we find no support for the internal consistency rationale; only delivered promises are relevant. In a second experiment designed to better understand what aspect of promise delivery influences promisor behavior, we manipulate whether the promise is delivered before or after the promisee is able to take a trusting action. We find late-arriving promises are relevant though not as relevant as promises delivered before the promisee chooses whether to take the trusting action. We conclude that implicit contracting does not fully explain promise keeping, because had it done so, late-arriving promises would also be irrelevant.

Recently, there has been a Renaissance for multi-level selection models to explain the persistence of unselfish behavior in social dilemmas, in which assortative/correlated matching plays an important role. In the current study of a multi-round prisoners’ dilemma experiment, we introduce two correlated matching procedures that match subjects with similar action histories together. We discover significant treatment effects, compared to the control procedure of random matching. Particularly with the weighted history matching procedure we find bifurcations regarding group outcomes. Some groups converge to the all-defection equilibrium even more pronouncedly than the control groups do, while other groups generate much higher rate of cooperation, which is also associated with higher relative reward for a typical cooperative action. All in all, the data show that cooperation does have a much better chance to persist in a correlated/assortative-matching environment, as predicted in the literature.

We investigate how employee potential influences wage offers and effort exertion in a gift exchange experiment. In particular, we test if gift exchange based on a commonly accepted norm for wage differentiation can emerge in a setting where the wage demands of agents are heterogeneous. We also analyse how communication by principals responds to the unequal wage demands and how it influences agents’ decisions about working effort in the presence of varying degrees of bargaining power. We find that differences in productivity and the resulting entitlements lead to differentiation in wages. High productivity agents are offered substantially higher wages than low productivity agents. Results from a control experiment suggest that a large part of this wage markup is related to the future productivity potential of high performers. At the same time, unequal wage schemes do not substantially crowd out effort exertion: we observe no strong detrimental effects from disadvantageous relative wage positions. Certain communication patterns significantly influence effort exertion.

A vast amount of empirical and theoretical research on public good games indicates that the threat of punishment can curb free-riding in human groups engaged in joint enterprises. Since punishment is often costly, however, this raises an issue of second-order free-riding: indeed, the sanctioning system itself is a common good which can be exploited. Most investigations, so far, considered peer punishment: players could impose fines on those who exploited them, at a cost to themselves. Only a minority considered so-called pool punishment. In this scenario, players contribute to a punishment pool before engaging in the joint enterprise, and without knowing who the free-riders will be. Theoretical investigations (Sigmund et al., Nature 466:861–863, 2010) have shown that peer punishment is more efficient, but pool punishment more stable. Social learning, i.e., the preferential imitation of successful strategies, should lead to pool punishment if sanctions are also imposed on second-order free-riders, but to peer punishment if they are not. Here we describe an economic experiment (the Mutual Aid game) which tests this prediction. We find that pool punishment only emerges if second-order free riders are punished, but that peer punishment is more stable than expected. Basically, our experiment shows that social learning can lead to a spontaneously emerging social contract, based on a sanctioning institution to overcome the free rider problem.

Monetary incentives are a procedural pillar in experimental economics. By applying four distinct monetary incentive schemes in three experimental finance applications, we investigate the impact of an incentive scheme’s salience on results and elicit subjects’ perception of the experienced scheme. We find (1) no differences in results between salient schemes but a significant impact if the incentive scheme is non-salient. (2) The number of previous participations has a significant impact on the perception of the incentive scheme by subjects: it strongly correlates with subjects’ motives for participation, positively contributes to subjects’ understanding of the incentive scheme, but has no influence on subjects’ motivation within the experiment. (3) Subjects favor more salient over less- or non-salient schemes in the gain domain and negatively evaluate high salience in the loss domain.

This paper reports findings of a laboratory experiment, which explores how reported self-assessment regarding the own relative performance is perceived by others. In particular, I investigate whether overconfident or underconfident subjects are considered as more likeable, and who of the two is expected to win in a tournament, thereby controlling for performance. Underconfidence beats overconfidence in both respects. Underconfident subjects are rewarded significantly more often than overconfident subjects, and are significantly more often expected to win. Subjects being less convinced of their performance are taken as more congenial and are expected to be more ambitious to improve, whereas overconfident subjects are rather expected to rest on their high beliefs. While subjects do not anticipate the stronger performance signal of underconfidence, they anticipate its higher sympathy value. The comparison to a non-strategic setting shows that men strategically deflate their self-assessment to be rewarded by others. Women, in contrast, either do not deflate their self-assessment or do so even in non-strategic situations, a behavior that might be driven by non-monetary image concerns of women.

We conduct a large scale experiment to investigate peer effects in computer assisted learning (CAL). Identification relies on three levels of randomization. We find an average 0.17 standard deviation improvement in math scores among primary school students. This average effect is the same for students treated individually or in pairs, implying that peer effects double the learning benefit from a given equipment. Among paired students, poor performers benefit more from CAL when paired with good performers and vice versa. Average performers benefit equally irrespective of who they are paired with. This suggests that the treatment is dominated by knowledge exchange between peers. We also find that CAL treatment reduces the dispersion in math scores and that the beneficial effects of CAL can be strengthened if weak students are systematically paired with strong students.

There is substantial evidence that women tend to support different policies and political candidates than men. Many studies also document gender differences in a variety of important preference dimensions, such as risk-taking, competition and pro-sociality. However, the degree to which differential voting by men and women is related to these gaps in more basic preferences requires an improved understanding. We conduct an experiment in which individuals in small laboratory “societies” repeatedly vote for redistribution policies and engage in production. We find that women vote for more egalitarian redistribution and that this difference persists with experience and in environments with varying degrees of risk. This gender voting gap is accounted for partly by both gender gaps in preferences and by expectations regarding economic circumstances. However, including both these controls in a regression analysis indicates that the latter is the primary driving force. We also observe policy differences between male- and female-controlled groups, though these are substantially smaller than the mean individual differences—a natural consequence of the aggregation of individual preferences into collective outcomes.

Experiments involving games have two dimensions of difficulty for subjects in the laboratory. One is understanding the rules and structure of the game and the other is forming beliefs about the behavior of other players. Typically, these two dimensions cannot be disentangled as belief formation crucially depends on the understanding of the game. We present the one-player guessing game, a variation of the two-player guessing game (Grosskopf and Nagel 2008), which turns an otherwise strategic game into an individual decision-making task. The results show that a majority of subjects fail to understand the structure of the game. Moreover, subjects with a better understanding of the structure of the game form more accurate beliefs of other player’s choices, and also better-respond to these beliefs.

Buying lottery tickets is not a rational investment from a financial point of view. Yet, the majority of people participate at least once a year in a lottery. We conducted a field experiment to increase understanding of lottery participation. Using representative data for the Netherlands, we find that lottery participation increased the happiness of participants before the draw. Winning a small prize had no effect on happiness. Our results indicate that people may not only care about the outcomes of the lottery, but also enjoy the game. Accordingly, we conclude that lottery participation has a utility value in itself and part of the utility of a lottery ticket is consumed before the draw.

The substantively rational value of the games studied in this paper does not help predict subject performance in the experiment at all. An accurate model must account for the cognitive ability of the people playing the game. This paper investigates whether the variation in measured rationality bounds is correlated with the probability of winning when playing against another person in games that exceed both players’ estimated rationality bound. Does seeing deeper into a game matter when neither player can see to the end of the game? Subjects with higher measured bounds win 63 percent of the time and the larger the difference the more frequently they win.

This paper examines a common value auction in which bidder default is explicitly allowed. The lack of contractual enforcement has implications for the formation of bids as well as the revenue properties of the auction. Using a common value procurement auction, we explore these implications in an experimental setting. Our results show that bidders are more aggressive when default is allowed. A theoretical result shows that allowing default can actually be in the best interest of the auctioneer. Experimental evidence, however, indicates that this result does not hold true in practice. One possible reason for this discrepancy is that the data in our experiments is consistent with winner's curse behavior.

The common-ratio effect and the Allais Paradox (common-consequence effect) are the two best‐known violations of Expected Utility Theory. We reexamine data from 39 articles reporting experiments (143 designs/parameterizations, 14,909 observations) and find that the common-ratio effect is systematically affected by experimental design and implementation choices. The common-ratio effect is more likely to be observed in experiments with a low common-ratio factor, a high ratio of middle to highest outcome, when lotteries are presented as simple probability distributions (not in a compound/frequency form), and with high hypothetical incentives.