We run a public good experiment in the field and in the lab with (partly) the same subjects. The field experiment is a true natural field experiment as subjects do not know that they are exposed to an experimental variation. We can show that subjects' behavior in the classic lab public good...

We run a public good experiment in the field and in the lab with (partly) the same subjects. The field experiment is a true natural field experiment as subjects do not know that they are exposed to an experimental variation. We can show that subjects' behavior in the classic lab public good...

To investigate the external validity of laboratory results, we combine a public good experiment with three treatments in a field experiment. One treatment offers the opportunity to free-ride, the other two are placebo treatments. We compare results within subjects. In the free-riding treatment,...

To investigate the external validity of laboratory results, we combine a public good experiment with three treatments in a field experiment. One treatment offers the opportunity to free-ride, the other two are placebo treatments. We compare results within subjects. In the free-riding treatment,...

Laboratory experiments are an important methodology in economics, especially in the field of behavioral economics. However, it is still debated to what extent results from laboratory experiments can be applied to field settings. One highly important question with respect to the external validity...

Laboratory experiments are an important methodology in economics, especially in the field of behavioral economics. However, it is still debated to what extent results from laboratory experiments can be applied to field settings. One highly important question with respect to the external validity...

To investigate the external validity of laboratory results, we combine a public good experiment with three treatments in a field experiment. One treatment offers the opportunity to free-ride, the other two are placebo treatments. We compare results within subjects. In the free-riding treatment,...

Results are reported of the first natural field experiment on the dictator game, where subjects are unaware that they participate in an experiment. In contrast to predictions of the standard economic model, dictators show a large degree of pro-social behavior. This paper builds a bridge from the...

We study how other-regarding behavior extends to environments with uncertain income and conditional commitments. Should fundraisers ask a banker to donate "if he earns a bonus" or wait and ask after the bonus is known? Standard EU theory predicts these are equivalent; loss-aversion and signaling...

Explaining the evolution and maintenance of cooperation among unrelated individuals is one of the fundamental problems in biology and the social sciences. Recent experimental evidence suggests that altruistic punishment is an important mechanism to maintain cooperation among humans. In this...