While confounding factors typically jeopardize the possibility to use observational data to measure peer effects, field experiments offer the possibility to obtain clean evidence. In this paper we measure the output of four randomly selected groups of individuals who were asked to fill letters...

While confounding factors typically jeopardize the possibility of using observational data to measure peer effects, field experiments over the potential for obtaining clean evidence. In this paper we measure the output of subjects who were asked to stuff letters into envelopes, with a...