The use of real monetary incentives has long defined experimental economics, setting it apart from disciplines like psychology, where hypothetical choices are common. While full-payment and hypothetical designs represent two clear extremes, random-payment incentive schemes – where one of several decisions is randomly selected for payment – have become a prominent approach in economics. Yet the behavioral validity of random-payment schemes remains underexamined: Do they more closely resemble fully incentivized tasks or hypothetical ones? We compare full-payment (participants paid for every decision), no-payment (participants not paid for any decision), and random-payment (participants paid for one randomly selected decision) incentive schemes, using five standard economic games to measure social preferences (Dictator Game, Ultimatum Game, Trust Game, Public Goods Game, and Prisoner’s Dilemma). Results from Experiment 1 (n = 1,501), with £1 stakes, indicate no significant differences between incentive schemes in any of the games included or a composite measure of prosocial behavior. In Experiment 2 (n = 750), with £10 stakes, results were largely in line with Experiment 1, suggesting no consistent behavioral impact of incentive schemes at increased stakes. The one notable exception was responder behavior in the Ultimatum Game, where participants in the full-payment condition were less likely to reject offers compared to those in the no-payment condition, with random-payment falling in between. Our results challenge the rigid disciplinary norm that real stakes are essential for valid measurement and invite a more nuanced consideration of how and when different incentive schemes are necessary or appropriate in behavioral research.

We develop and validate a survey instrument to elicit six key economic preferences in children: undefined time preferences, risk preferences, altruism, positive reciprocity, negative reciprocity, and trust. The survey was administered to a sample of 339 nine-year-old children, for whom we also collected behavioral data through incentivized choice experiments targeting the same preferences. Our econometric analysis allows us to identify a set of 14 survey items that best predict children’s experimental behavior. For each preference, we also compare the predictive power of this 14-item validated survey to a shorter 9-item self-evaluation version. Our results demonstrate that these surveys provide a simple and reliable tool for measuring individual preferences in children – enabling researchers to account for heterogeneity when designing and evaluating policies targeting younger populations.

Recent studies showing that some outcome variables do not statistically significantly differ between real-stakes and hypothetical-stakes conditions have raised methodological challenges to experimental economics’ disciplinary norm that experimental choices should be incentivized with real stakes. I show that the hypothetical bias measures estimated in these studies do not econometrically identify the hypothetical biases that matter in most modern experiments. Specifically, traditional hypothetical bias measures are fully informative in ‘elicitation experiments’ where the researcher is uninterested in treatment effects (TEs). However, in ‘intervention experiments’ where TEs are of interest, traditional hypothetical bias measures are uninformative; real stakes matter if and only if TEs differ between stakes conditions. I demonstrate that traditional hypothetical bias measures are often misleading estimates of hypothetical bias for intervention experiments, both econometrically and through re-analyses of three recent hypothetical bias experiments. The fact that a given experimental outcome does not statistically significantly differ on average between stakes conditions does not imply that all TEs on that outcome are unaffected by hypothetical stakes. Therefore, the recent hypothetical bias literature does not justify abandoning real stakes in most modern experiments. Maintaining norms that favor completely or probabilistically providing real stakes for experimental choices is useful for ensuring externally valid TEs in experimental economics.

Do large language models (LLMs) – such as ChatGPT-3.5 Turbo, ChatGPT-4.0, and Gemini 1.0 Pro, and DeepSeek-R1 – simulate human behavior in the context of the Prisoner’s Dilemma (PD) game with varying stake sizes? Through a replication of Yamagishi et al. (2016) ‘Study 2,’ we investigate this question, examining LLM responses to different payoff stakes and the influence of stake order on cooperation rates. We find that LLMs do not mirror the inverse relationship between stake size and cooperation found in the study. Rather, some models (DeepSeek-R1 and ChatGPT-4.0) almost wholly defect, while others (ChatGPT-3.5 Turbo and Gemini 1.0 Pro) mirror human behavior only under very specific circumstances. LLMs demonstrate sensitivity to framing and order effects, implying the need for cautious application of LLMs in behavioral research.

We study how competition impacts security-bid auctions by comparing Monopolistic and Competitive auctions. Sellers choose their security designs between debt and equity, and buyers select auctions based on sellers’ choices. We find that an auction’s security design has limited influence on revenue under monopoly, whereas equity substantially increases revenue under competition due to equity attracting more bidders. Despite this, sellers’ rate of choosing equity does not differ between the treatments. While theory suggests that security choice when acting as a buyer should be negatively correlated to one’s choice as a seller, we find the empirical correlation to be positive.

Many important decisions, for example, applying to college, require an individual to simultaneously submit several applications. These decisions are unique as each application is risky because acceptance is uncertain while also being rival as one can only attend a single college. In an influential theoretical analysis of these problems, Chade and Smith (2006) establish the No Safety Schools Theorem which suggests larger portfolios are riskier than single choices. We offer experimental evidence, using several experiments, that this theorem is routinely violated. In fact, the majority of our subjects violate this theorem. However, performance improves with practice, advice, and feedback.

We present a simple and robustly incentive-compatible price list methodology to elicit quantiles of a subjective real-valued belief. These elicited quantiles can be employed to approximate a subject’s complete subjective distribution, and we establish that the distribution maximizing entropy while adhering to the elicited quantiles is piecewise linear. Using this approach, our methodology extends to estimating arbitrary unobserved attributes of the subjective distribution, such as mean and variance, which are otherwise challenging to elicit. We provide a proof-of-concept for our framework through an experiment involving the elicitation of participants’ beliefs regarding the mathematical abilities of their peers.

Using data from a large-scale behavioral experiment in Beijing, we investigate how social efficiency orientation may relate to rice culture proxied by the rice farming ratio in the subject’s birth province. We find that the observed behavior in several behavioral games that enhances social efficiency is positively associated with the rice farming ratio. This is corroborated by a further analysis of data related to giving help from the China Family Panel Studies. The overall finding supports our hypothesis that rice culture fosters the individual’s intrinsic preference toward greater social efficiency.

We report a lab experiment to study subjects’ preferences over their ordinal rank in an earnings distribution. Following an assignment of unequal earnings, subjects can select a monetary transfer from exactly one individual to another, not including themselves. This can potentially change their own position in the distribution, as well as influence overall inequality. The experiment varies whether the initial earnings assignment is random or is affected by preliminary competition. It also varies the reference group from a complete to a partial network. A majority of observed transfers reduce inequality by moving earnings from those with the highest rank to the lowest rank in the distribution. Rank-improving transfers are substantially more common for preliminary competition losers than winners. Transfers to individuals outside of the reference group are not uncommon, and they usually target as the source the individuals high in the income distribution. While generally weak overall, own rank preferences appear to be more common among men than women.

This paper is a single-project meta-analysis of four experiments that model charitable giving as individual contributions to a multiplicity of competing threshold public goods. We pool 17,136 observations at the individual level to summarize the project and investigate the role of learning, gender, and risk attitude, since the included studies are inconclusive in this regard. We find that equally effective coordination devices are the existence of a single contribution option that stands out on its merits, learning, and delegation as long as the intermediary is formally obliged to pass along a high enough percentage of the transferred resources. Women delegate less than men, and consequently prefer direct contributions. Risk tolerance increases overall donations but decreases individual earnings. We discuss possible implications of our findings.

The money-burning game (MBG) is widely used to study anti-social or destructive behavior. We extend the design of the MBG to separate three motives that could lead subjects to burn their partner’s money – spite, reciprocity, and inequality aversion. We detect that reciprocity is the dominant reason: Most of our subjects would only burn their partner’s money if they believed that their partner would burn theirs. This finding has important implications for the interpretation of the behavior of the game.

Bayesian estimates from experimental data can be influenced by highly diffuse or “uninformative” priors. This paper gives examples of how diffuse priors can affect estimates, and discusses how practitioners can use their expertise to critique and select a prior.1

We report two meta-analyses on the determinants of antisocial behavior in experimental settings in which such behavior is not rationally motivated by pecuniary incentives. The first meta-analysis employs aggregate data from 95 published and unpublished studies (24,086 participants), using laboratory, field and online experiments carried out since 2000. We find that antisocial behavior depends significantly on the experimental setting, being highest in vendetta games and lowest in social dilemmas. As we find significant heterogeneity across the studies, including across game classes, in the second meta-analysis, we focus only on “Joy of Destruction” (JoD) and money-burning (MB) experiments, for which we have the most observations, 51 studies and around 16,784 participants. Overall, our findings suggest that procedural fairness and being observed by others reduce the frequency of antisocial behavior. Online and field experiments display more antisocial behavior than laboratory experiments. We also find that the strategy method biases antisocial behavior upward. However, we do not find evidence for a positive publication bias being correlated with higher destructive behavior, either in the general meta-analysis or in relation to JoD/MB experiments; if anything, there is evidence of a negative publication bias. The JoD/MB meta-analysis finds evidence of a price effect for destruction frequency, negative discrimination against outsiders, within-subject designs underestimating destructive behavior, and more antisocial behavior in one-shot interactions. Collectively, our results point to the value of more laboratory experiments that systematically build on paradigmatic experimental designs to enable comparability and the identification of key economic drivers of antisocial behavior.

Explicit and implicit incentives and opportunities for mutually beneficial voluntary cooperation coexist in many economic relationships. In a series of eight laboratory gift-exchange experiments, we show that incentives can lead to crowding out of voluntary cooperation even after they have been abolished. This crowding-out also occurs in repeated relationships, which otherwise strongly increase effort compared to one-shot interactions. Using a unified econometric framework, we unpack these results as a function of positive and negative reciprocity, as well as the principals’ wage offer and the incentive compatibility of the contract. Crowding-out occurs mostly due to reduced wages and not a change in reciprocal wage–effort relationships. Our systematic analysis also replicates established results on gift exchange, incentives, and crowding out of voluntary cooperation while being exposed to incentives. Overall, our findings show that the behavioral consequences of explicit incentives strongly depend on the features of the situation in which they are embedded.

I experimentally investigate whether there is a gender difference in advice giving in a gender-neutral task with varying difficulty in which the incentives of the sender and the receiver are perfectly aligned. I find that women are more reluctant to give advice compared to men for difficult questions. The gender difference in advice giving cannot be explained by gender differences in performance. Self-confidence explains some of the gender gap, but not all. The gender gap disappears if advice becomes enforceable. Introducing a model of guilt and responsibility, I discuss possible underlying mechanisms that are consistent with the findings.

We experimentally test the predictive success of three stationary concepts in two cyclic duopoly games. The concepts are Nash equilibrium, impulse-balance equilibrium and payoff-sampling equilibrium. In the experiment 11 independent subject groups, consisting out of six participants interacting over 200 rounds, were gathered for each game. The comparison of the three concepts with mixed strategies shows that the order of performance from best to worst is as follows: payoff-sampling equilibrium, impulse-balance equilibrium, and Nash equilibrium. In addition the data exhibit a weak but significant tendency over time in the direction of coordination at a pure strategy equilibrium.

Studies of experimental and betting markets have shown that markets are able to efficiently aggregate information dispersed over many traders. We study information aggregation in Arrow–Debreu markets using a novel information structure. Compared to previous studies, the information structure is more complex, allows for heterogeneity in information among traders—which provides insights into the way in which information is gradually disseminated in the market—and generates situations in which all traders hold identical beliefs over the traded assets’ values, thus providing a harsh stress test for belief updating. We find little evidence for information aggregation and dissemination in early rounds. Nonetheless, after traders gain experience with the market mechanism and structure, prices converge to reveal the true state of the world. Elicited post-market beliefs reveal that markets are able to efficiently aggregate dispersed information even if individual traders remain uninformed, consistent with the marginal trader hypothesis.

When it comes to experiments with multiple-round decisions under risk, the current payoff mechanisms are incentive compatible with either outcome weighting theories or probability weighting theories, but not both. In this paper, I introduce a new payoff mechanism, the Accumulative Best Choice (“ABC”) mechanism that is incentive compatible for all rational risk preferences. I also identify three necessary and sufficient conditions for a payoff mechanism to be incentive compatible for all models of decision under risk with complete and transitive preferences. I show that ABC is the unique incentive compatible mechanism for rational risk preferences in a multiple-task setting. In addition, I test empirical validity of the ABC mechanism in the lab. The results from both a choice pattern experiment and a preference (structural) estimation experiment show that individual choices under the ABC mechanism are statistically not different from those observed with the one-round task experimental design. The ABC mechanism supports unbiased elicitation of both outcome and probability transformations as well as testing alternative decision models that do or do not include the independence axiom.

We experimentally analyze the role of speculators, who have no use value for the objects on sale, in auctions. The environment is a uniform-price sealed-bid auction for 2 identical objects, followed by a free-form bargaining resale market, with one positive-value bidder, and either one or two speculators who may choose simultaneously whether to enter the auction. We show that the bidder accommodates speculators by reducing demand in the auction and subsequently purchasing in the resale market, which encourages entry by speculators. The presence of multiple speculators induces each speculator to enter less often, but increases competition in the auction and the auction price. Speculators earn positive profits on average, except when multiple speculators enter the auction.

We study whether CEOs of private firms differ from other people with regard to their strategic decisions and beliefs about others’ strategy choices. Such differences are interesting since CEOs make decisions that are economically more relevant, because they affect not only their own utility or the well-being of household members, but the utility of many stakeholders inside and outside of the organization. They also play a central role in shaping values and norms in society. We expect differences between both groups, because CEOs are more experienced with strategic decision making than comparable people in other professional roles. Yet, due to the difficulties in recruiting this high-profile group for academic research, few studies have explored how CEOs make incentivized decisions in strategic games under strict controls and how their choices in such games differ from those made by others. Our study combines a stratified random sample of 200 CEOs of medium-sized firms with a carefully selected control group of 200 comparable people. All subjects participated in three incentivized games—Prisoner’s Dilemma, Chicken, Battle-of-the-Sexes. Beliefs were elicited for each game. We report substantial and robust differences in both behavior and beliefs between the CEOs and the control group. The most striking results are that CEOs do not best respond to beliefs; they cooperate more, play less hawkish and thereby earn much more than the control group.