One of the important contributions of the past 30 years of research has been to clarify the concepts involved in the tragedy of the commons. Things are not as simple as they seem in the prototypical model. Human motivation is complex, the rules governing real commons do not always permit free access to everyone, and the resource systems themselves have dynamics that influence their response to human use. The result is often not the “tragedy” described by Hardin but what [Bonnie] McCay has described as a “comedy”—a drama for certain, but one with a happy ending.