We define social reciprocity as the act of demonstrating one's disapproval, at some personal cost, for the violation of widely-held norms (e.g., don't free ride). Social reciprocity differs from standard notions of reciprocity because social reciprocators intervene whenever a norm is violated...

Monitoring by peers is often an effective means of attenuating incentive problems. Most explanations of the efficacy of mutual monitoring rely either on small group size or on a version of the Folk theorem with repeated interactions which requires reasonably accurate public information...

In many environments, tournaments can elicit more effort from workers, except perhaps when workers can sabotage each other. Because it is hard to separate effort, ability and output in many real workplace settings, the empirical evidence on the incentive effect of tournaments is thin. There is...

A key open question for theories of reference-dependent preferences is what determines the reference point. One candidate is expectations: what people expect could affect how they feel about what actually occurs. In a real-effort experiment, we manipulate the rational expectations of subjects...

We investigate how group boundaries, and the economic environment surrounding groups, affect altruistic cooperation and punishment behavior. Our study uses experiments conducted with 525 officers in the Swiss Army, and exploits random assignment to platoons. We find that, without competition...

Recent experiments show that public goods can be provided at high levels when mutual monitoring and costly punishment are allowed. All these experiments, however, study monitoring and punishment in a setting where all agents can monitor and punish each other (i.e., in a complete network). The...

We ask whether conformity, copying the most observed behavior in a population, can affect free riding in a public goods situation. Our model suggests that, if free riding is sufficiently frequent at the start of a public goods game, conformity will increase the growth rate of free riding. We...

While many experiments demonstrate that the actual behavior is different than predicted behavior, they have not shown that economic reasoning is necessarily incorrect. Instead, these experiments illustrate that the problem with homo economicus is that his preferences have been mis-specified....

Many experiments have demonstrated the power of norm enforcement-peer monitoring and punishment-to maintain, or even increase, contributions in social dilemma settings, but little is known about the underlying norms that monitors use to make punishment decisions. Using a large sample of...

Aspiration-based evolutionary dynamics have recently been used to model the evolution of fair play in the ultimatum game showing that incredible threats to reject low offers persist in equilibrium. We focus on two extensions of this analysis: we experimentally test whether assumptions about...