An effective way to foster cooperation is to monitor behaviour and sanction freeriding. Yet, previous studies have shown that cooperation quickly declines when sanctioning mechanisms are removed. We test if explicitly expressing trust in players' capability to maintain cooperation after the...

We introduce a novel concept, group image concerns, showing that individuals change their behavior and are willing to incur personal costs to cultivate a positive image of their groups. We develop an experimental method to identify and quantify group image concerns, and conduct a series of...

A stream of research examining the effect of punishment on conformity indicates that punishment can backfire and lead to suboptimal social outcomes. We examine whether this effect is due to a lack of perceived legitimacy of rule enforcement, enabling agents to justify selfish behavior. We...

We use large-scale survey data of German speaking villages from the 1930's to investigate drivers of cooperation, gender, and religious norms. Through geographic cluster analysis, we show that inter-regional variation explains only little heterogeneity in norms. Villages in the same physical and...

We investigate the relationship between political attitudes and prosociality in a survey of a representative sample of the U.S. population during the first summer of the COVID-19 pandemic. We find that an experimental measure of prosociality correlates positively with adherence to protective...

We show that financial advisors recommend more costly products to female clients, based on minutes from about 27,000 real-world advisory meetings and client portfolio data. Funds recom-mended to women have higher expense ratios controlling for risk, and women less often receive rebates on...

Overconfidence is one of the most ubiquitous cognitive bias. There is copious evidence of overconfidence being relevant in a diverse set of economic domains. In this paper, we relate the recent concept of cognitive uncertainty with overconfidence. Cognitive uncertainty represents a decision...

How does a citizen's decision to participate in political activism depend on the participation of others? We conduct a nation-wide natural field experiment in collaboration with a major European party during a recent national election. In a party survey, we randomly provide canvassers with true...

We present a field experiment to study the effects of non-monetary incentives on healthy food choices of 282 children in elementary schools. Previous interventions have typically paid participants for healthy eating, but this often may not be feasible. We introduce a system where food items are...

Many intertemporal trade-offs are unbalanced: while the advantages of options are concen- trated in a few periods, the disadvantages are dispersed over numerous periods. We provide novel experimental evidence for “concentration bias”, the tendency to overweight advantages that are...