Common Pool Resources

Common pool resources (CPRs) are characterized as resources for which the exclusion of users is difficult (referred to as excludability), and the use of such a resource by one user decreases resource benefits for other users (referred to as subtractability). Common CPR examples include fisheries, forests, irrigation systems, and pastures. Global CPR examples include the earth’s oceans and atmosphere. Difficulty in excluding users, combined with a CPR’s subtractability, create management vulnerabilities that can result in resource degradation, often referred to as the “tragedy of the commons” (see the General Overviews section). The difficulty of exclusion means that if some individuals invest in protecting a CPR, others might still benefit without contributing to its management. Individuals may not have an incentive to curtail their use of a CPR because the cost of their use of a CPR is shared by all users. If resource users do not restrain their use of a CPR or contribute to CPR management, the result is often the depletion or degradation of the CPR’s quality. The importance of such “tragedies” is evident in anecdotal examples, from the devastation of tropical rain forests to the depletion of local and regional fish stocks. At the same time, CPR scholars have found many examples that suggest that people are capable of averting these tragedies and sustaining CPRs. Scholars have devoted considerable attention to understanding the nature of CPR dilemmas, the conditions under which people are able to work together to address them, and what makes the rules or institutions that people devise in managing CPRs successful. Examples of institutional responses include resource privatization or private property rights, government management, and community management through collective action, among others (see the CPR Dilemma Solutions section). The variety of disciplines that contribute to the CPR literature include, but are not limited to, anthropology, agriculture, biology, ecology, engineering, law, political science, public administration, rural sociology, and sociology. A research program that has become well known for its multidisciplinary and expansive research on CPRs centers on the scholarship of Dr. Elinor Ostrom, who won the 2009 Nobel Prize in Economic Sciences for her research on how local communities around the world have devised institutions to sustainably manage CPRs. The bulk of initial CPR research from the Ostrom school and others focused on a limited set of smaller, often community managed, CPRs, such as a pasture, groundwater basin, or local fishery (see the Established CPR Literature section). In the decades of vigorous research that has ensued, scholars have explored the wide variation that exists among CPR settings and contexts, including methodological and empirical challenges and opportunities for testing and advancing theory in these diverse settings. The methods employed in CPR studies (see the Methods section) include case studies, game theory, field experiments, and large-n statistical analyses. Additionally, researchers have grappled with issues of large and interconnected CPRs, such as marine commons and interstate river basins (see the Scale and Complexity section), and they have begun to test the applicability of established CPR theory to new contexts, such as the information commons (see the Nontraditional CPR Applications section). Although the works cited in this article are not an exhaustive list of all CPR publications, they illustrate the variety and promise of the CPR literature, from established and classic works to recent and emerging CPR applications.