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.

This paper introduces new experimental designs to examine how conditional cooperation and punishment behaviours respond to the full range of variation in the contributions of others. It is shown that contributions become significantly more selfish-biased as others contribute more unequally, while punishment increases both with decreasing contributions by the target player and increasing contributions by a third player. Low contributors who punish antisocially do not direct their punishment specifically toward high contributors, while their beliefs indicate that they expect to themselves be punished.

We propose a novel experimental method that disentangles strategically- and non-strategically-motivated behavior. We apply it to an indefinitely-repeated prisoner's dilemma game to observe simultaneously how the same individual behaves in situations with future interaction and in situations with no future interaction, while controlling for expectations. This method allows us to determine the extent to which strategically-cooperating individuals are responsible for the observed pattern of cooperation in experiments with repeated interaction, including the so-called endgame effect. Our results indicate that the most common motive for cooperation in repeated games is strategic.

The highly popular belief that rent-control leads to an increase in the amount of affordable housing is in contradiction with ample empirical evidence and congruent theoretical explanations. It can therefore be qualified as a misconception. We present the results of a preregistered on-line experiment in which we study how to dispel this misconception using a refutational approach in two different formats, a video and a text. We find that the refutational video has a significantly higher positive impact on revising the misconception than a refutational text. This effect is driven by individuals who initially agreed with it and depart from it after the treatment. The refutational text, in turn, does not have a significant impact relative to a non-refutational text. Higher cognitive reflective ability is positively associated with revising beliefs in all interventions. Our research shows that visual communication effectively reduces the gap between scientific economic knowledge and the views of citizens.

Past experimental research has shown that when rating systems are available, buyers are more generous in accepting unfair offers in ultimatum bargaining. However, it also suggests that, under these conditions, sellers behave more fairly to avoid receiving negative feedback. This paper experimentally investigates which effect is stronger with the use of a rating system: buyers’ inflated inequity acceptance or sellers’ disapproval aversion. We explore this question by varying the information condition on the buyers’ side. Our experiment shows that in a setup where the size of the pie is common knowledge for both buyers and sellers, when a rating system is present, the sellers exhibit disapproval aversion but the buyers do not display greater acceptance of inequity. By contrast, when only sellers are aware of the size of the pie, sellers behave aggressively to exploit buyers and their behavior does not change in the presence of a rating system; however, buyers display greater acceptance of inequity when a rating system is present. We discuss how these results can be explained by a theoretical model that includes sellers’ social disapproval aversion and buyers’ disappointment aversion in addition to the players’ inequality aversion.

A rich history of theoretical models in finance shows that speculation can lead to overpricing and price bubbles. We provide evidence that, indeed, individual speculative behavior fuels overpricing in (experimental) asset markets. In a first step, we elicit individual speculative behavior in a one-shot setting with a novel speculation elicitation task (SET). In a second step, we use this measure of speculative behavior to compose dynamic, continuous double auction markets in line with Smith et al. (Econometrica 56(5):1119–1151, 1988). We find significant higher overpricing in markets with traders who exhibited more speculative behavior in the individual SET. However, we find no such differences in overpricing when we test for alternative explanations, using a market environment introduced by Lei, Noussair, and Plott (Econometrica 69(4):831–859, 2001) where speculation is impossible. Taken together, our results corroborate the notion that speculation is an important factor in overpricing and bubble formation if market environments allow for the pursuit of capital gains.

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.

The paper surveys the experimental literature on centralized matching markets, covering school choice and college admissions models. In the school choice model, one side of the market (schools) is not strategic, and rules (priorities) guide the acceptance decisions. The model covers applications such as school choice programs, centralized university admissions in many countries, and the centralized assignment of teachers to schools. In the college admissions model, both sides of the market are strategic. It applies to college and university admissions in countries where universities can select students, and centralized labor markets such as the assignment of doctors to hospitals. The survey discusses, among other things, the comparison of various centralized mechanisms, the optimality of participants’ strategies, learning by applicants and their behavioral biases, as well as the role of communication, information, and advice. The main experimental findings considered in the survey concern truth-telling and strategic manipulations by the agents, as well as the stability and efficiency of the matching outcome.

We report the results from an experiment designed to measure attitudes towards ambiguity beyond ambiguity aversion. In particular, we implement recently-proposed model-free preference conditions of ambiguity prudence and ambiguity temperance. Ambiguity prudence has been shown to play an important role in precautionary behavior and the mere presence of ambiguity averse agents in markets. We observe that the majority of individuals’ decisions are consistent with ambiguity aversion, ambiguity prudence and ambiguity temperance. This finding confirms the prediction of many popular (specifications of) ambiguity models and has important implications for models of prevention behavior.

Nothing is known about the effectiveness of defaults when moving the target outcomes requires substantial effort. We conduct two field experiments to investigate how defaults fare in such situations: we change the university exam sign-up procedure in two study programs to “opt-out” (a) for a single exam, and (b) for many exams. Both interventions increase task uptake (exam sign-up). Concerning the outcomes which require effort, we find no effects for many exams. For a single exam, the opt-out increases task completion (exam participation) in the study program where the default arguably entails stronger endorsement. Within this program, the effects on successful task completion (exam passing) are heterogeneous: treated students who in the past were willing to communicate with the university (responsive individuals) invest more effort into exam preparation and are more likely to pass the exam than their control counterparts.For non-responsive individuals, we find increased sign-ups but no effects on the target outcomes. Defaults can thus be effective and may be an attractive policy option even when the target outcome requires substantial effort provision. It is, however crucial that the interventions target the appropriate individuals.

We design a laboratory experiment to examine predictions of trustworthiness in a novel three-person trust game. We investigate whether and why observers of the game can predict the trustworthiness of hand-written communications. Observers report their perception of the trustworthiness of messages, and make predictions about the senders’ behavior. Using observers’ decisions, we are able to classify messages as “promises” or “empty talk.” Drawing from substantial previous research, we hypothesize that certain factors influence whether a sender is likely to honor a message and/or whether an observer perceives the message as likely to behonored: the mention of money; the use of encompassing words; and message length. We find that observers have more trust in longer messages and “promises”; promises that mention money are significantly more likely to be broken; and observers trust equally in promises that do and do not mention money. Overall, observers perform slightly better than chance at predicting whether a message will be honored. We attribute this result to observers’ ability to distinguish promises from empty talk, and to trust promises more than empty talk. However, within each of these two categories, observers are unable to discern between messages that senders will honor from those that they will not.

Individuals were found to anonymously predict positive election outcomes for their preferred candidate. Yet, there is little scientific knowledge about election predictions made in the context of same-camp political communications (i.e., partisan communications) that are presumably meant to encourage other supporters. In five studies of low-information elections and a study of hypothetical U.S. elections (n = 1889), we found that people tended to communicate favorable forecasts to others sharing their view, compared to the neutral point and to the actual election outcomes. On the other hand, negative framing reduced the positivity of forecasts in these communications to the extent that it led most participants to predict an election loss. This occurred in response to a single addressee acting discordantly and even more strongly when the election results were phrased as a drop. When both positive and negative framing options were available, this still negativity affected participants’ predictions even though only a minority selected the negative framing option. Thus, people tend to make optimistic election predictions in partisan communications, but this pattern is easily manipulable given subtle changes in the forecasting prompt, either by negative framing or selectable positive and negative framing.

Overbidding in sealed-bid second-price auctions (SPAs) has been shown to be persistent and associated with cognitive ability. We study experimentally to what extent cross-game learning can reduce overbidding in SPAs, taking into account cognitive skills. Employing an order-balanced design, we use first-price auctions (FPAs) to expose participants to an auction format in which losses from high bids are more salient than in SPAs. Experience in FPAs causes substantial cross-game learning for cognitively less able participants but does not affect overbidding for the cognitively more able. Vice versa, experiencing SPAs before bidding in an FPA does not substantially affect bidding behavior by the cognitively less able but, somewhat surprisingly, reduces bid shading by cognitively more able participants, resulting in lower profits in FPAs. Thus, ‘cross-game learning’ may rather be understood as ‘cross-game transfer’, as it has the potential to benefit bidders with lower cognitive ability whereas it has little or even adverse effects for higher-ability bidders.

We examine how multitasking affects performance. We also examine whether individuals optimally choose their degree of multitasking or whether they perform better under an externally imposed schedule. Subjects in our experiment perform two different tasks according to one of three treatments: one where they perform the tasks sequentially, one where they are forced to multitask, and one where they can freely organize their work. Subjects who are forced to multitask perform significantly worse than those forced to work sequentially. Surprisingly, subjects who can freely organize their own schedule also perform significantly worse. These results suggest that scheduling is a significant determinant of productivity. Finally, our results do not support the stereotype that women are better at multitasking. Women suffer as much as men when forced to multitask and are actually less inclined to multitask when being free to choose.

We study the impact of endowments and expectations on reference point formation and measure the value of food safety certification in the context of fish trading on real markets in Nigeria. In our field experiment, consumers can trade a known food item for a novel food item that is superior in terms of food safety––or vice versa. Endowments matter for reference point formation, but we also document a reverse endowment effect for a subsample of respondents. The effect of expectations about future ownership is weak and mixed. While expectations seem to affect bidding behavior for subjects “trading up” to obtain the certified food product (a marginally significant effect), it does not affect bids for subjects “trading down” to give up this novel food item. Finally, willingness to pay for safety certified food is large for our respondents—our estimate of the premium is bounded between 37 and 53% of the price of conventional, uncertified food.

Many experiments investigating different decision theories have relied heavily on pairwise choices between lotteries. These are easy to incentivise, but often yield only limited dichotomous information. This paper considers whether respondents’ judgments about their strength of preference (SoP) for one alternative over another can usefully supplement standard choice data. We report extensive evidence that such judgments show sensitivity to variations in question format and parameter values in the directions we should expect, not only within-subject but also between-sample. We illustrate how such judgments can usefully supplement standard pairwise choice data and enrich our understanding of observed behaviour.

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.

Does political polarization lead to dysfunctional behavior? To study this question, we investigate the attitudes of supporters of Donald Trump and of Hillary Clinton towards each other and how these attitudes affect spiteful behavior. We find that both Trump and Clinton supporters display less positive attitudes towards the opposing supporters compared to coinciding supporters. More importantly, we show that significantly more wealth is destroyed if the opponent is an opposing voter. This effect is mainly driven by Clinton voters. This provides the first experimental evidence that political polarization leads to destructive behavior.

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.

In a Diamond–Dybvig type model of financial intermediation, we allow depositors to announce at a positive cost to subsequent depositors that they keep their funds deposited in the bank. Theoretically, the mere availability of public announcements (and not its use) ensures that no bank run is the unique equilibrium outcome. Multiple equilibria—including bank run—exist without such public announcements. We test the theoretical results in the lab and find a widespread use of announcements, which we interpret as an attempt to coordinate on the no bank run outcome. Withdrawal rates in general are lower in information sets that contain announcements.