Abstract

Following Ostrom's definition, the concept of common-pool resources refers to subtractable natural or artificial resources where the exclusion of potential users is difficult or costly. Rejecting Hardin's "Tragedy of the commons" model, the theory shows nowadays the possibility of fully endogenous CPRs management. This conclusion, based most on empirical experience, focuses on resource users' capability of building governing institutions without the enforcement of external authorities. Different variables influence the probability of successful CPRs management. The Institutional Analysis and Development (IAD) framework identifies three different groups of factors - physical, institutional, and social - which affect individual incentives for cooperative resource use, and its application is a fundamental step for both theoretical and empirical analysis. Nevertheless, the CPRs theory need further developments, both for its application to meso-scale (i.e. regional-scale) resources and for better understanding relations between social and institutional factors affecting the possibility of successful long term management.