Behavior in the local commons is usually embedded in a context of regulations and social norms that the group of users face. Such norms and rules affect how individuals value material and non-material incentives and therefore determine their decision to cooperate or over extract the resources from the common-pool. This paper discusses the importance of social norms in shaping behavior in the commons through the lens of experiments, and in particular experiments conducted in the field with people that usually face these social dilemmas in their daily life. Through a large sample of experimental sessions with around one thousand people between villagers and students, I test some hypothesis about behavior in the commons when regulations and social norms constrain the choices of people. The results suggest that people evaluate several components of the intrinsic and material motivations in their decision to cooperate. While responding in the expected direction to a imperfectly monitored fine on over extraction, the expected cost of the regulation is not a sufficient explanatory factor for the changes in behavior by the participants in the experiments. Even with zero cost of violations, people can respond positively to an external regulator that issues a normative statement about a rule that is aimed at solving the social dilemma.
