While individuals are expected to perceive similarly identical quantities, regardless of the used units (e.g., 1 ton or 1000 kg), several scholars suggest that consumers over-infer quantities when they are presented in bigger and phonetically longer numbers. In two experimental studies, we examine this numerosity bias in the context of household food waste. Unlike previous scholars, manipulating numerosity revealed no effect: perceptions of food waste volume and likelihood to reduce it are not influenced by the used numeric value (2500 g vs. 2.5 kg; Study 1) nor the number of syllables (two kilos eight hundred seventy-five grams vs. three kilograms; Study 2).

How are partnerships between foreign states and armed groups formed? Previous research has suggested that the provision of external support is mainly based on group capacity and affinity ties. However, this neglects the fact that support provision is a dynamic matching process in which strategic adjustments often are made that enable the distribution of support. I argue that states place demands on rebel groups who may strategically rebrand, reform, and reorganise to facilitate the distribution of support. For state sponsors, this process serves the dual purpose of justification and control. For rebels, the process distinguishes them from competitors and increases their chances of receiving vital aid. Drawing on frame analysis, I illustrate how the Syrian Democratic Forces crafted narratives in tandem with the United States which created the necessary conditions that helped initiate and sustain the partnership. The findings highlight the importance of the strategic alignment process and show how it can supplement existing explanations related to battlefield performances and transnational affinities.

We construct moduli spaces of framed logarithmic connections and also moduli spaces of framed parabolic connections. It is shown that these moduli spaces possess a natural algebraic symplectic structure. We also give an upper bound of the transcendence degree of the algebra of regular functions on the moduli space of parabolic connections.

The justifiably famous “Asian disease” experiment (ADE) by Tversky and Kahneman established that choices involving uncertainty can be dependent on framing. Description emphasizing gains induced much higher preference for choices in which outcomes were described as certain rather than probabilistic, as compared to description emphasizing losses. The vignette for the ADE involved disease mitigation, and the COVID pandemic gave it much-enhanced realism and immediacy. An attempt to replicate the ADE during the pandemic, however, failed to produce the original results. Other, contemporaneous replications, by contrast, matched the original, leaving open the question of when such framing effects occur.

Especially in the context of climate adaptation policy, creating support for hard policy instruments and convincing people that their individual contributions do matter are two significant challenges. In this study, we test the effect of an individually versus collectively framed gain-appeal infographic on the acceptance of hard policy instruments and this in the context of strictly private climate change adaptation behaviour. We used a mixed methods approach focussing on reducing private paving in domestic gardens in Belgium. Evidence from an online survey experiment (n = 3,389) showed that policy makers implementing a collectively framed infographic can increase the acceptance of a more strict permit policy and a yearly financial contribution, while simultaneously enhancing personal and collective self-efficacy and outcome expectancy beliefs. Complementary insights from qualitative data learned that perceived (in)equity is a crucial point of attention when designing climate policies addressing private paving. A collectively framed infographic may convey the message ‘yes, we ánd I can’. With these “findings, we want to trigger new opportunities in climate policies beyond the current policy scopes.

The gift-exchange game is a form of sequential prisoner's dilemma, developed by Fehr et al. (1993), and popularized in a series of papers by Ernst Fehr and co-authors. While the European studies typically feature a high degree of gift exchange, the few U.S. studies provide some conflicting results. We find that the degree of gift exchange is surprisingly sensitive to an apparently innocuous change—whether or not a comprehensive payoff table is provided in the instructions. We also find significant and substantial time trends in responder behavior.

We use different incentive schemes to study truth-telling in a die-roll task when people are asked to reveal the number rolled privately. We find no significant evidence of cheating when there are no financial incentives associated with the reports, but do find evidence of such when the reports determine financial gains or losses (in different treatments). We find no evidence of loss aversion in the standard case in which subjects receive their earnings in a sealed envelope at the end of the session. When subjects manipulate the possible earnings, we find evidence of less cheating, particularly in the loss setting; in fact, there is no significant difference in behavior between the non-incentivized case and the loss setting with money manipulation. We interpret our findings in terms of the moral cost of cheating and differences in the perceived trust and beliefs in the gain and the loss frames.

In this paper, we present a first survey of the literature regarding whether the strategy method, in which a responder makes conditional decisions for each possible information set, leads to different experimental results than does the more standard direct-response method, in which the responder learns the action of the first mover and then chooses a response. Of the twenty-nine existing comparisons, sixteen find no difference, while four do find differences, and nine comparisons find mixed evidence. We also find some indications about the underlying determinants of when the two methods lead to different responses. For example, it appears that levels of punishment are substantially lower with the strategy method. In addition, it also appears that difference across these elicitation methods are more likely when people make fewer contingent choices. Finally, in no case do we find that a treatment effect found with the strategy method is not observed with the direct-response method.

Leadership mechanisms provide a potential means to mitigate social dilemmas, but empirical evidence on the success of such mechanisms is mixed. In this paper, we explore the institutional frame as a relevant factor for the effectiveness of leadership. We compare subjects’ behavior in public-goods experiments that are either framed positively (give-some game) or negatively (take-some game). We observe that leader and follower decisions are sensitive to the institutional frame. Leaders contribute less in the take-some game, and the correlation between leaders’ and followers’ contribution is weaker in the take-some game. Additionally, using a strategy method to elicit followers’ reactions at the individual level, we find evidence for the malleability of followers’ revealed cooperation types. Taken together, the leadership institution is found to be less efficient in the take- than in the give-frame, both in games that are played only once and repeatedly.

In an artefactual field experiment, we implemented a crowdfunding campaign for an institute’s summer party and compared donation and contribution framings. We found that the use of the word ‘donation’ generated higher revenue than the use of ‘contribution.’ While the individuals receiving the donation framing gave substantially larger amounts, those receiving the contribution framing responded more strongly to reward thresholds and suggestions. An additional survey experiment on MTurk indicated that the term ‘donation’ triggers more positive emotional responses and that emotions are highly correlated with giving. It appears that making a donation is perceived as a more voluntary act and is thus more successful at generating warm glow than making a contribution. We surmise that this extends to other funding mechanisms.

An influential result in the literature on charitable giving is that matching subsidies dominate rebate subsidies in raising funds. We investigate whether this result extends to “unit donation” schemes, a popular alternative form of soliciting donations. There, the donors’ choices are over the number of units of a charitable good to fund at a given unit price, rather than the amount of money to give. Comparing matches and rebates as well as simple discounts on the unit price, we find no evidence of dominance in our online experiment: the three subsidy types are equally effective overall. At a more disaggregated level, rebates lead to a higher likelihood of giving, while matching and discount subsidies lead to larger donations by donors. This suggests that charities using a unit donation scheme enjoy additional degrees of freedom in choosing a subsidy type. Rebates merit additional consideration if the primary goal is to attract donors.

Experimenter demand effects refer to changes in behavior by experimental subjects due to cues about what constitutes appropriate behavior. We argue that they can either be social or purely cognitive, and that, when they may exist, it crucially matters how they relate to the true experimental objectives. They are usually a potential problem only when they are positively correlated with the true experimental objectives’ predictions, and we identify techniques such as non-deceptive obfuscation to minimize this correlation. We discuss the persuasiveness or otherwise of defenses that can be used against demand effects criticisms when such correlation remains an issue.

We explore the effects of the provision of an information-processing instrument—payoff tables—on behavior in experimental oligopolies. In one experimental setting, subjects have access to payoff tables whereas in the other setting they have not. It turns out that this minor variation in presentation has non-negligible effects on participants’ behavior, particularly in the initial phase of the experiment. In the presence of payoff tables, subjects tend to be more cooperative. As a consequence, collusive behavior is more likely and quickly to occur.

Many previous experiments document that behavior in multi-person settings responds to the name of the game and the labeling of strategies. With a few exceptions, these studies cannot tell whether frames affect preferences or beliefs. In three large experiments, we investigate whether social framing effects are also present in Dictator games. Since only one of the subjects makes a decision, the frame can affect behavior merely through preferences. In all the experiments, we find that behavior is insensitive to social framing. We discuss how to reconcile the absence of social framing effects in Dictator games with the presence of social framing effects in Ultimatum games.

Three experiments are designed to test if the level of irrelevant prizes in the menu has a positive (assimilation) or negative (contrast) effect on the perceived valuation of target objects. Familiar field prizes and binary lotteries over such prizes are placed within “more-expensive” and “less-expensive” menus. Subjects fill-in a sequence of binary choice problems to reveal their preference between given cash and a designated prize from the menu. Between-subject comparisons reveal that the prize-level in the menu positively affects perceived valuations in spite of procedural attempts to rule out menu-dependent preferences and prohibit experimenter bias. The effect also shows within-subject in auction experiments: the price that subjects are willing to pay for given monetary lotteries significantly increases with the average payoff in the irrelevant-menu. The bias finally manifests even when subjects are led to choose the target lottery, independently, from the underlying menu.

We replicate three tasks for which Gneezy, List and Wu (Q. J. Econ. 121(4):1283—1309, 2006) document the so-called uncertainty effect: People value a binary lottery over non-monetary outcomes less than other people value the lottery's worse outcome. While the authors implement verbal lottery descriptions, we use a physical lottery format and also provide subjects with complete information about the goods they are to value. We observe for all three pricing tasks that subjects’ willingness to pay for the lottery is significantly higher than other subjects’ willingness to pay for the lottery's worse outcome.

We exploit testing data to gain better understanding on framing effects on decision-making and performance under risk. In a randomized field experiment, we modified the framing of scoring rules for penalized multiple-choice tests. In penalized multiple-choice tests, right answers are typically framed as gains while wrong answers are framed as losses (Mixed-framing). In the Loss-framing proposed, both non-responses and wrong answers are presented in a loss domain. According to our theoretical model, we expect the change in the framing to decrease students’ non-response and to increase students’ performance. Under the Loss-framing, students’ non-response reduces by a 18%-20%. However, it fails to increase students’ scores. Indeed, our results support the possibility of impaired performance in the Loss-framing.

The axioms of expected utility and discounted utility theory have been tested extensively. In contrast, the axioms of social welfare functions have only been tested in a few questionnaire studies involving choices between hypothetical income distributions. In a controlled experiment with 100 subjects placed in the role of social planners, we test five fundamental properties of social welfare functions to determine the efficacy of traditional social choice models in predicting social planner allocations when presented with choice sets designed to test the axioms of the theory. We find that three properties of the standard social welfare functions tested are systematically violated, producing an Allais paradox, a common ratio effect, and a framing effect in social choice. We find support for scale invariance and a preference for tail-increasing transfers. Our experiment also enables us to test a model of salience-based social choice which predicts the systematic deviations and highlights the close relationship between these anomalies and the classical paradoxes for risk and time.

In standard trust games, no trust is the default, and trust generates a potential gain. We investigate a reframed trust game in which full trust is default and where no trust generates a loss. We find significantly lower levels of trust and trustworthiness in the loss domain when full trust is default than in the gain domain when no trust is default. As a consequence, trust is on average profitable in the gain domain, but not in the loss domain. We also find that subjects respond more positively to higher trust in the loss domain than in the gain domain.

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.