The practice and theory of collective action is constrained by a dearth of rigorous empirical tests of why and how such institutions emerge and evolve, and under what conditions they can be successful. Empirical analyses of cooperative watershed management in Haiti reveal that, given a conducive environment and political leadership, groups will emerge and survive where a "critical mass" of individuals have practical knowledge of the potential gains from action. Emergence can be constrained in the short run by: 1. (a)landscape factors that affect the potential net economic gain, and 2. (b)sociocultural factors that affect the cost of constructing the new institution.