Evidence from psychology and economics indicates that many individuals overestimate their ability, both absolutely and relatively. We test three different theories about observed relative overconfidence. The first theory notes that simple statistical comparisons (for example, whether the...

There is by now ample evidence from laboratory experiments that individuals exhibit "prosocial" or "other-regarding" preferences. However, a key question is whether the importance of other-regarding preferences documented in the laboratory can be readily generalized to draw conclusions about the...

We measure a specific form of other-regarding behavior, costly cooperation with an anonymous other, among 645 subjects at a trucker training program in the Midwestern US. Using subjects' second-mover strategy in a sequential form of the Prisoners' Dilemma, we categorize subjects as: Free Rider,...

Spillovers of prosocial motivation are crucial for the formation of social capital. They facilitate interactions among individuals and create social multipliers that amplify the effects of policy interventions. We conducted a large-scale intervention study among dyads of blood donors to...

Evidence from psychology and economics indicates that many individuals overestimate their ability, both absolutely and relatively. We test three different theories about observed relative overconfidence. The first theory notes that simple statistical comparisons (for example, whether the...

Does social recognition motivate prosocial individuals? We run large-scale experiments at Italy's main blood donors association, testing social recognition in social media and peer groups. We experimentally disentangle visibility concerns and peer comparisons, and study how exposure to different...