In an unmanaged or weakly governed common-pool resource, where users capture private gains while sharing depletion costs, individually rational extraction can produce overuse.
Hardin's 1968 essay, and Ostrom showed managed commons frequently avoid it. Hardin's own case was unmanaged open access, which is the condition Ostrom's design principles remove.
In practice
- A fishery with no licences and no quota is emptied by boats that would each have preferred a stock that lasted.
- A shared team inbox that belongs to everyone is answered by nobody; the same inbox with a named rota is answered.
- Possible explanations
- The mechanism is the split between private gain and shared cost: each user takes the whole benefit of one more unit and bears only a fraction of the depletion.
- In its favour
- It describes open-access resources well, including ocean fisheries and groundwater, where extraction has repeatedly exceeded renewal.
- Against it
- Ostrom's field studies found communities managing shared resources sustainably for centuries under their own rules, so the tragedy follows from absent governance rather than from common ownership. Hardin's essay also drew population-control conclusions his evidence did not support.
- Standing
- Ostrom showed managed commons frequently avoid it.
- Further reading
- Wikipedia
- Subject
- Economics & Incentives
- Essay
- The theories behind every argument about money