Clean Evidence on Peer Effects
通过对比两人同室工作与单独工作的实验，发现同伴效应会缩小产出差异、提高平均生产率，且低生产率工人对同伴行为最敏感。
We study subjects who were asked to fill letters into envelopes with a remuneration independent of output. In the "pair" treatment, two subjects worked at the same time in the same room, and peer effects were possible. In the "single" treatment, subjects worked alone, and peer effects were ruled out. We find evidence of peer effects in the pair treatment because the standard deviations of output are smaller within pairs than between pairs. Moreover, average output is higher in the pair treatment: thus, peer effects raise productivity. Finally, low-productivity workers are the most sensitive to the behavior of peers.