In refereed journals, with link to data/replication package (OSF page) where available

• Uncertainty about Carbon Impact and the Willingness to Avoid CO2 Emissions, with Taisuke Imai, Davide D. Pace and Peter Schwardmann, Ecological Economics, forthcoming. (Supersedes Tinbergen WP 059/2020 — “Curbing carbon”.)
  [.pdf]          Journal Page       OSF page      Abstract
  Using data from a large representative survey, we document that consumers are very uncertain about the emissions associated with various actions, which may affect their willingness to reduce their carbon footprint. We then experimentally test two channels for the behavioral impact of such uncertainty, namely risk aversion about the impact of mitigating actions and the formation of motivated beliefs about this impact. In two novel large online experiments (N=2,219), participants make incentivized trade-offs between personal gain and (uncertain) carbon impact. We find no evidence that uncertainty affects individual climate change mitigation efforts through risk aversion or motivated belief channels. The results suggest that reducing consumer uncertainty through information campaigns is not a policy panacea and that communicating scientific uncertainty around climate impact need not backfire.
   
  
  
• Individual and contextual effects of attention in risky choice, with Alejandro Hirmas and Jan Engelmann, Experimental Economics, forthcoming.
  [.pdf]         Journal Page     Abstract
  We investigate the role of visual attention in risky choice in a rich experimental dataset that includes eye-tracking data. We first show that attention is not reducible to individual and contextual variables, which explain only 20% of attentional variation. We then decompose attentional variation into individual average attention and trial-wise deviations of attention to capture different cognitive processes. Individual average attention varies by individual, and can proxy for individual preferences or goals (as in models of “rational inattention” or goal-directed attention). Trial-wise deviations of attention vary within subjects and depend on contextual factors (as in models of “salience” or stimulus-driven attention). We find that both types of attention predict behavior: average individual attention patterns are correlated with individual levels of loss aversion and capture part of this individual heterogeneity. Adding trial-wise deviations of attention further improves model fit. Our results show that a decomposition of attention into individual average attention and trial-wise deviations of attention can capture separable cognitive components of decision making and provides a useful tool for economists and researchers from related fields interested in decision-making and attention.
  
  
  
• Fair Shares and Selective Attention, with Dianna Amasino and Davide Pace, American Economic Journal: Microeconomics, 2024, 16:4, 259–290.
  [.pdf]         Journal page      OSF page      Abstract
  Attitudes towards fairness and redistribution differ along socio-economic lines, resulting in political conflict. To understand the formation of such views and find levers to affect them, we study the role of attention. In a large online experiment, we investigate how subjects allocate their visual attention to the contributions of merit and luck in the generation of a surplus and how they decide on its division. We find that subjects who randomly obtained an advantaged position pay less attention to information about true merit and retain more of the surplus. Both the attentional and behavioral patterns persist, although with smaller effect sizes, when dictators subsequently divide money between pairs of advantaged and disadvantaged subjects in the role of a benevolent judge. Moreover, attention has a substantial causal effect: forcing subjects to look for one second more at merit information relative to overall outcomes reduces the effect of having an advantaged position on allocations by about 40%. The evidence is consistent with a habit formation effect of attention in fairness decisions. These findings open a new window on socio-economic cleavages in attitudes towards redistribution, and suggest that attention-based policy interventions may be effective in reducing polarized views on inequality.
   
  
  
• Anticipatory Anxiety and Wishful Thinking, with Jan Engelmann, Maël Lebreton, Nahuel Salem, and Peter Schwardmann, American Economic Review, 2024, 114(4): 926-60.
  [pdf]           Journal page       OSF page        Abstract
  Across five experiments (N=1,714), we test whether people engage in wishful thinking to alleviate anxiety about adverse future outcomes. Participants perform pattern recognition tasks in which some patterns may result in an electric shock or a monetary loss. Diagnostic of wishful thinking, participants are less likely to correctly identify patterns that are associated with a shock or loss. Wishful thinking is more pronounced under more ambiguous signals and only reduced by higher accuracy incentives when participants’ cognitive effort reduces ambiguity. Wishful thinking disappears in the domain of monetary gains, indicating that negative emotions are important drivers of the phenomenon.
   
  Media: Medium, Uni. Amsterdam
  
  
• Self-serving Bias in Redistribution Choices: Accounting for Beliefs and Norms, with Dianna Amasino and Davide Pace, Journal of Economic Psychology, 2023, 98 (October): 102654
  [.pdf]     Journal Page     OSF page     Abstract
  We explore the psychological mechanisms underlying self-serving redistribution decisions in an experimental setting. This self-serving bias in redistribution has been attributed not only to self-interest, but also to constructs such as differing beliefs about the hard work or luck underlying inequality, differing fairness views, and differing perceptions of social norms. In this study, we directly measure each of these potential mechanisms and compare their mediating roles in the relationship between status and redistribution. In our experiment, participants complete real-effort tasks and then are randomly assigned a high or low pay rate per correct answer to exogenously induce (dis)advantaged status. Participants are then paired and those assigned the role of dictator decide how to divide their joint earnings. We find that advantaged dictators keep more for themselves than disadvantaged dictators and report different fairness views and beliefs about task performance, but not different perceptions of social norms. Further, only fairness views play a significant mediating role between status and allocation differences, suggesting this is the primary mechanism underlying self-serving differences in support for redistribution.
   
  
  
• Ignorance by Choice: A Meta-Analytic Review of the Underlying Motives of Wilful Ignorance and Its Consequences, with Linh Vu, Margarita Leib, Ivan Soraperra and Shaul Shalvi, Psychological Bulletin, 2023, 149 (9–10): 611–635.
  [pdf]         Journal Page         Data         Code         Abstract
  People sometimes avoid information about the impact of their actions as an excuse to be selfish. Such “willful ignorance” reduces altruistic behavior and has detrimental effects in many consumer and organizational contexts. We report the first meta-analysis on willful ignorance, testing the robustness of its impact on altruistic behavior and examining its underlying motives. We analyze 33,603 decisions made by 6,531 participants in 56 different treatment effects, all employing variations of an experimental paradigm assessing willful ignorance. Meta-analytic results reveal that 40% of participants avoid easily obtainable information about the consequences of their actions on others, leading to a 15.6-percentage-point decrease in altruistic behavior compared to when information is provided. We discuss the motives behind willful ignorance and provide evidence consistent with excuse-seeking behaviors to maintain a positive self-image. We investigated the moderators of willful ignorance and address the theoretical, methodological, and practical implications of our findings on who engages in willful ignorance, as well as when and why.
  
  Media: La Repubblica, Forbes, Süddeutsche Zeitung, The Morning News, Express.
  
  
• The Social Construction of Ignorance: Experimental Evidence, with Shaul Shalvi, Ivan Soraperra and Marie-Claire Villeval, Games and Economic Behavior, 2023, 138: 197-213.
  [.pdf]       Journal page       OSF page       Abstract
  We experimentally study the social transmission of inconvenient information, that is, information about externalities generated by one’s own decision, through the matching of supply and demand for ignorance. We show that willful ignorance arises from two, interacting sources. First, informed senders suppress a substantial amount of “inconvenient” information, driven by the wish to relieve the decision maker as well as the sender’s own preferences for information. Second, about one-third of decision makers avoids senders who transmit inconvenient information (“shooting the messenger”). On aggregate, this leads to assortative matching between senders and decision makers based on preferences for information states. Compared to random matching, assortative matching leads to a stronger expression of individual preferences: selfish senders remain ignorant and donate less, while altruistic senders seek out informative senders and give more. We discuss applications to information sharing in social networks and to organizational design.
   
  
  
• Self-Persuasion: Evidence from field experiments at international debating competitions, with Egon Tripodi and Peter Schwardmann, American Economic Review, 2022, 112 (4): 1118-46.
  [.pdf]     Journal page       Replication package       Econimate video       Abstract
  Laboratory evidence shows that when people have to argue for a given position, they persuade themselves about the position’s factual and moral superiority. Such self-persuasion limits the potential of communication to resolve conflict and reduce polarization. We test for this phenomenon in a field setting, at international debating competitions that randomly assign experienced and motivated debaters to argue one side of a topical motion. We find self-persuasion in factual beliefs and confidence in one’s position. Effect sizes are smaller than in the laboratory, but robust to a one-hour exchange of arguments and a ten-fold increase in incentives for accuracy.
   
  Media:  BBC, Süddeutsche Zeitung, AEA Chart of the week
  

• Casting doubt: Image concerns and the communication of social impact, with Manuel Foerster, Economic Journal, 2021, 131: 2887–2919. 
  [.pdf]     Journal page     OSF page       Abstract
  We investigate strategic communication about the social impact of costly prosocial actions. A ‘sender’ with noisy information about impact sends a cheap-talk message to a ‘receiver’, upon which both agents choose whether to act. In the presence of social preferences and image concerns, the sender trades off persuasion, exaggerating impact to induce receiver action, and justification, downplaying impact to cast doubt on the effectiveness of action and excuse her own passivity. In an experiment on charitable giving we find evidence for both motives. In line with our theory and a justification motive, increasing image concerns reduces communication of positive impact.
  
  Older version with more general model: Denial and alarmism in collective action problems, TI working paper 019/2018.

• Overconfidence and gender gaps in redistributive preferences: Cross-Country experimental evidence,  with Thomas Buser, Gianluca Grimalda and Louis Putterman, Journal of Economic Behavior and Organization, 2020, 178, 267–286. 
  [.pdf]     Journal page     Abstract
  Gender differences in voting patterns and political attitudes towards redistribution are well-documented. The experimental gender literature suggests several plausible behavioral explanations behind these differences, relating to gender differences in confidence concerning future relative income position, risk aversion, and social preferences. We use data from lab experiments on preferences for redistribution conducted in the U.S. and several European countries to investigate gender differences and their causes. On aggregate, women’ s demand for redistribution is higher than men’ s, but the differences vary considerably across locations and countries. Moreover, the gender difference appears only when the source of inequality is based on relative abilities, but not when it is based on luck. Our most robust finding is that across all sampled locations, men’ s relatively higher (over)confidence in their abilities, in comparison to women, leads them to specify lower redistribution levels. We discuss the role of confidence in accounting for gender differences in political and redistributive choices outside the lab.
  
  Blogs: Psychology Today, OECD Development Matters, ESB.

• Bracelets of pride and guilt? An experimental test of self-signaling, with Ferdinand von Siemens, Journal of Economic Behavior and Organization, 2020, 172, 280-91.
  [.pdf]     Journal page     OSF page     Abstract
  Self-signaling theory argues that behavior is important to build up or maintain a favorable self-image. We provide a novel test of this argument by manipulating the importance of behavior for future self-image. In two experiments, part of the subject pool is incentivized to wear bracelets as reminders of their initial identity-relevant behavior. We find some evidence that the bracelets increase anticipated memory, which should make behavior more relevant for managing a positive self-image. However, we find no evidence for self-signaling. Instead, our results suggest that participants resolve cognitive dissonance by constructing self-serving rationalizations of their actions that serve as cheap substitutes for self-signaling.
  
  

• Deception and Self-Deception, with Peter Schwardmann, Nature Human Behaviour, 2019, 3:10, 1055-61.
  [.pdf]      Journal page      OSF page      Abstract
  There is ample evidence that the average person thinks he or she is more skilful, more beautiful and kinder than others and that such overconfidence may result in substantial personal and social costs. To explain the prevalence of overconfidence, social scientists usually point to its affective benefits, such as those stemming from a good self-image or reduced anxiety about an uncertain future. An alternative theory, first advanced by evolutionary biologist Robert Trivers, posits that people self-deceive into higher confidence to more effectively persuade or deceive others. Here we conduct two experiments (combined n = 688) to test this strategic self-deception hypothesis. After performing a cognitively challenging task, half of our subjects are informed that they can earn money if, during a short face-to-face interaction, they convince others of their superior performance. We find that the privately elicited beliefs of the group that was informed of the profitable deception opportunity exhibit significantly more overconfidence than the beliefs of the control group. To test whether higher confidence ultimately pays off, we experimentally manipulate the confidence of the subjects by means of a noisy feedback signal. We find that this exogenous shift in confidence makes subjects more persuasive in subsequent face-to-face interactions. Overconfidence emerges from these results as the product of an adaptive cognitive technology with important social benefits, rather than some deficiency or bias.
  
  Blog posts: Psychology Today, Nature Research, Darwinian Business, FehrAdvice, Imperfect Cognitions.
  Media: ABC News, FAZ, Folia, MSN, Wirtschaftswoche, Phys.org, Süddeutsche Zeitung, BBC.
  

• On esteem-based incentives, with Ali Mazyaki, International Review of Law Economics, 2019, 60, 105848.
  [.pdf]      Journal page       Abstract
  The rise of the internet, increased connectivity and higher availability of personal data increases the rele-vance of incentives based on reputation and the allocation of esteem. However, their use is controversial:critics argue that shaming can lead to a loss of control over the size of the sanction and to mob justice. Weuse the signaling model of social behavior by Bénabou and Tirole (2011) to explore the effect of esteem-based incentives and their interaction with traditional fines. We show that the use of esteem and stigmacan indeed lead to a loss of control by generating multiple equilibria, some of which feature high levels ofcompliance and high levels of stigma. Moreover, the deterrent effect of monetary and esteem incentivesis interdependent. If both types of incentives are costly to implement, esteem incentives should optimallybe used relatively more for rare behaviors and in societies that have more heterogeneous values.
  
  

• Peer effects and risk sharing in experimental asset markets , with Paul Gortner, European Economic Review, 2019, 116, 129-147. 
  [.pdf]     Journal page     OSF page     Abstract
  We investigate the effect of introducing information about peer portfolios in an experi- mental Arrow–Debreu economy. Confirming the prediction of a general equilibrium model with inequality averse preferences, we find that peer information leads to reduced vari- ation in payoffs within peer groups. Information also improves risk sharing, as the data suggests that experiencing earnings deviations from peers induces a shift to more balanced portfolios. In a treatment where we highlight the highest earner, we observe a reduction in risk sharing, while highlighting the lowest earner has no effects compared to providing neutral information. Our results indicate that the presence of social information and its framing is an important determinant of equilibrium in financial markets.
  
  

• Responsiveness to feedback as a personal trait , with Thomas Buser and Leonie Gerhards, Journal of Risk and Uncertainty, 2018, 56:2, 165-192.
  [.pdf]     Journal page     OSF page     Abstract
  We investigate individual heterogeneity in the tendency to under-respond to feedback (“conservatism”) and to respond more strongly to positive compared to negative feedback (“asymmetry”). We elicit beliefs about relative performance after repeated rounds of feedback across a series of cognitive tests. Relative to a Bayesian benchmark, we find that subjects update on average conservatively but not asymmetrically. We define individual measures of conservatism and asymmetry relative to the average subject, and show that these measures explain an important part of the variation in beliefs and competition entry decisions. Relative conservatism is correlated across tasks and predicts competition entry both independently of beliefs and by influencing beliefs, suggesting it can be considered a personal trait. Relative asymmetry is less stable across tasks, but predicts competition entry by increasing self-confidence. Ego-relevance of the task correlates with relative conservatism but not relative asymmetry.

• Self-image and willful ignorance in social decisions, with Zachary Grossman, Journal of the European Economic Association, 2017, 15:1, 173-217.
  [.pdf]     Journal page     Abstract
  Avoiding information about adverse welfare consequences of self-interested decisions, or willful ignorance, is an important source of socially harmful behavior. To understand this issue, we analyze a Bayesian signaling model of an agent who cares about self-image and has the opportunity to learn the social benefits of a personally costly action. We show that willful ignorance can serve as an excuse for selfish behavior by obfuscating the signal about the decision-maker’s preferences, and help maintain the idea that the agent would have acted virtuously under full information. We derive several behavioral predictions that are inconsistent with either outcome-based preferences or social-image concern and conduct experiments to test them. Our findings, as well as a number of previous experimental results, offer support for these predictions and thus, the broader theory of self-signaling.
  
  Media:  Summary blogpost at Oxford University Press.

• Dual-Process Reasoning in Charitable Giving: Learning from Non-results, with Zachary Grossman,  Games, 2017, 8:3, 36-49. 
  [.pdf]     Journal page     Abstract
  To identify dual-process reasoning in giving, we exposed experimental participants making a charitable donation to vivid images of the charity’s beneficiaries in order to stimulate affect. We hypothesized that the effect of an affective manipulation on giving would be larger when we simultaneously put the subjects under cognitive load using a numerical recall task. Independent treatment checks reveal opposite responses in men and women and cast some doubt on the reliability of our mainstream treatment manipulations and assessment tools. We find no evidence for dual-process decision-making, even among women, whose responses to the manipulations conformed most to our expectations. These results highlight the need for caution in the use of these common manipulations, the importance of independent manipulation checks, and the limitations of dual-process models for understanding altruistic behavior. 

• A method to elicit beliefs as most likely intervals, with Karl Schlag, Judgment and Decision Making, 2015, 10:5, 456-468. 
  [.pdf]     Journal page     Abstract
  We show how to elicit the beliefs of an expert in the form of a “most likely interval”, a set of future outcomes that are deemed more likely than any other outcome. Our method, called the Most Likely Interval elicitation rule (MLI), asks the expert for an interval and pays according to how well the answer compares to the actual outcome. We show that the MLI performs well in economic experiments, and satisfies a number of desirable theoretical properties such as robustness to the risk preferences of the expert.
  
  Earlier version with more theoretical results: Incentives for Eliciting Confidence Intervals.

• A penny for your thoughts: A survey of methods for eliciting beliefs, with James Tremewan and  Karl Schlag, Experimental Economics, 2015, 18:3, 457-490. 
  [.pdf]     Journal page     Abstract
  Incentivized methods for eliciting subjective probabilities in economic experiments present the subject with risky choices that encourage truthful reporting. We discuss the most prominent elicitation methods and their underlying assumptions, provide theoretical comparisons and give a new justification for the quadratic scoring rule. On the empirical side, we survey the performance of these elicitation methods in actual experiments, considering also practical issues of implementation such as order effects, hedging, and different ways of presenting probabilities and payment schemes to experimental subjects. We end with a discussion of the tradeoffs involved in using incentives for belief elicitation and some guidelines for implementation.

• Preferences for redistribution and perception of fairness: an experimental study, with Ruben Durante and Louis Putterman, Journal of the European Economic Association, 2014, 12:4, 1059-1086.
  [.pdf]     Journal page     Abstract
  We conduct a laboratory experiment to study how demand for redistribution of income depends on self-interest, insurance motives, and social concerns relating to inequality and efficiency. Our choice environments feature large groups of subjects and real-world framing, and differ with respect to the source of inequality (earned or arbitrary), the cost of taxation to the decision maker, the dead-weight loss of taxation, uncertainty about own pretax income, and whether the decision maker is affected by redistribution. We estimate utility weights for the different sources of demand for redistribution, with the potential to inform modeling in macroeconomics and political economy.

• Resisting moral wiggle room: how robust is reciprocal behaviour?, with Julija Kulisa, Michael Kosfeld and Guido Friebel, American Economic Journal: Microeconomics, 2014, 6:3, 256-64. 
  [.pdf]     Journal page     Abstract
  We provide the second mover in a trust game and a moonlighting game with an excuse for not reciprocating. While this type of manipulation has been shown to strongly reduce giving in the dictator game, we find that the availability of the excuse has no effect on the incidence of reciprocal behavior in these games. Our results cast doubt on the generalizability of previous dictator game findings and suggest that image concerns are not a key driver of reciprocal behavior.

• Eliciting probabilities, means medians, variance and covariances without assuming risk neutrality, with Karl Schlag, Theoretical Economics Letters, 2013, 3:1, 38-42.
  [.pdf]     Journal page     Abstract
  We are interested in incentivizing experimental subjects to report their beliefs truthfully, without imposing assumptions on their risk preferences. We prove that if subjects are not risk neutral, it is not possible to elicit subjective probabilities or the mean of a subjective probability distribution truthfully using deterministic payments schemes, which are predominant in the literature. We present a simple randomization trick that transforms deterministic rewards into randomized rewards, such that agents with arbitrary risk preferences report as if they were risk neutral. Using this trick, we show how to elicit probabilities, means, medians, variances and covariances of the underlying distribution without assuming risk neutrality.

• Sanctions that signal: an experiment, with Roberto Galbiati and Karl Schlag, Journal of Economic Behavior and Organization, 2013, 94, 34-51. 
  [.pdf]     Journal page     Abstract
  The introduction of sanctions provides incentives for more pro-social behavior, but may also be a signal that non-cooperation is prevalent. In an experimental minimum-effort coordination game we investigate the effects of the information contained in the choice to sanction. We compare the effect of sanctions that are introduced exogenously by the experimenter to that of sanctions which have been actively chosen by a subject who has superior information about the previous effort of the other players. We find that cooperative subjects perceive actively chosen sanctions as a negative signal which significantly reduces the effect of sanctions.

• Status-Seeking in Criminal Subcultures and the Double Dividend of Zero-Tolerance, with Robert Dur, Journal of Public Economic Theory, 2013, 15:1, 77-93. 
  [.pdf]     Journal page Abstract
  This paper offers a new argument for why a more aggressive enforcement of minor offenses (zero-tolerance) may yield a double dividend in that it reduces both minor offenses and more severe crime. We develop a model of criminal subcultures in which people gain social status among their peers for being “tough” by committing criminal acts. As zero-tolerance keeps relatively “gutless” people from committing a minor offense, the signaling value of that action increases, which makes it attractive for some people who would otherwise commit more severe crime. If social status is sufficiently important in criminal subcultures, zero-tolerance reduces crime across the board.

• The signaling power of sanctions in social dilemmas, Journal of Law, Economics and Organization, 2012, 28:1, 103-25.
  [.pdf]     Journal page     Abstract
  Evidence from field and laboratory experiments indicates that a large fraction of the people behave like conditional cooperators in public good games. In this article, I investigate the implications of the existence of both conditional cooperators and egoists for optimal law enforcement strategies. When norms of cooperation exist between conditional cooperators, sanctions set by an authority can be lower than in a “Hobbesian” setting where everybody is egoistic. Moreover, if the authorities have private information about the fraction of egoists in society, low sanctions can be optimal because they signal that there are few defectors and thus “crowd in” trust and cooperation between agents. In social dilemmas where conditional cooperation is an important factor, as is the case in tax compliance, the model provides a rationale for the low observed sanctions in the real world and the mixed evidence on the effectiveness of deterrence.

• Beyong the state of nature: Introducing social interactions in the economic model of crime, Review of Law & Economics, 2012, 8:1, 401–32.
  [.pdf]     Journal page    Abstract
  The standard economic model of crime emphasizes the individual rationality and agency of criminals, while sociological theories typically emphasize the importance of social forces. This essay surveys a recent strand of literature on law enforcement that bridges these two approaches. Using the tools of game theory, it investigates crime as the outcome of the interaction between rational individuals. The survey shows that this analysis leads to a substantially richer set of hypotheses regarding the effect of enforcement than the standard economic model, depending on the classification of the social context, or game, in which agents operate. In doing so, it brings rational choice theories in line with long-standing insights in the field of criminology, as well as providing new analytical distinctions and generalizations.

Non-refereed

• The broken window effect, with Mataka Flynn and Rogier van der Wolk. Encyclopedia of Law and Economics, 2017.Do small signs of neighborhood disorder lead to crime?
  [.pdf]

• The Ecological and Economic Conditions of Exploitation Strategies. 
  Burton-Chellew, M., Kacelnik, A., Arbilly, M., dos Santos, M., Mathot, K.M., McNamara, J.M., Mengel, F., van der Weele, J. and Vollan, B. 2017. In:Investors and Exploiters in Ecology and Economics: Principles and Applications, edited by L-A. Giraldeau, P. Heeb, and M. Kosfeld. Strüngmann Forum Reports, vol. 21 J. Lupp, series editor. Cambridge, MA: MIT Press