Common-pool resources (CPRs) are a category in the standard economic typology of goods, distinguished by two features: subtractability (one person's use reduces what is available to others) and low excludability (it is costly or impractical to prevent others from accessing the resource). This combination separates CPRs from pure public goods (non-rival, non-excludable), club goods (non-rival, excludable), and private goods (rival, excludable).
Classic examples include ocean fisheries, irrigation systems, grazing lands, aquifers, forests, and the global atmosphere as a sink for greenhouse gases. Because individual users capture the full benefit of their extraction while the costs of depletion are spread across all users, CPRs are prone to overuse — a dynamic Garrett Hardin popularised as the "tragedy of the commons" in his 1968 Science essay.
Elinor Ostrom's empirical work, summarised in Governing the Commons (1990), challenged the assumption that only privatisation or state control can avert collapse. Studying irrigation associations, Swiss alpine pastures, Japanese village forests, and coastal fisheries, she identified eight design principles for durable self-governance, including clearly defined boundaries, congruence between rules and local conditions, collective-choice arrangements, monitoring, graduated sanctions, and nested governance. Ostrom shared the 2009 Nobel Memorial Prize in Economic Sciences for this research.
CPR analysis underpins much of international environmental diplomacy. Negotiations over straddling fish stocks under the 1995 UN Fish Stocks Agreement, transboundary watercourses, and climate mitigation regimes such as the 2015 Paris Agreement all wrestle with classic CPR dilemmas: free-riding, monitoring costs, and the absence of a central enforcer. The framework is also applied to newer domains including the radio spectrum, orbital slots, antibiotics (resistance as commons depletion), and open-source software repositories.
Key analytical questions for researchers: Who are the users? What are the resource boundaries? What monitoring and sanctioning institutions exist? And at what scale — local, national, regional, or global — is collective action feasible?
Example
The 1995 UN Fish Stocks Agreement was negotiated to address common-pool resource problems in high-seas fisheries, where states like Canada and Spain had clashed in the 1995 "Turbot War" over straddling stocks in the Northwest Atlantic.
Frequently asked questions
Both are hard to exclude users from, but CPRs are rivalrous — one user's consumption diminishes what's left for others. Public goods like national defence or lighthouse signals are non-rivalrous.
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