Tragedy of the commons

The tragedy of the commons is a metaphoric label for a concept that is widely discussed, and criticised, in economics, ecology and other sciences. According to the concept, should a number of people enjoy unfettered access to a finite, valuable resource such as a pasture, they will tend to over-use it, and may end up destroying its value altogether. Even if some users exercised voluntary restraint, the other users would merely supplant them, the predictable result being a tragedy for all.

The metaphor is the title of a 1968 essay by ecologist Garrett Hardin. As another example, he cited a watercourse which all are free to pollute. The concept itself did not originate with Hardin, but rather extends back to classical antiquity, being discussed by Aristotle.

The principal concern of Hardin's essay was overpopulation of the planet. To prevent the inevitable tragedy (he argued) it was necessary to reject the principle (supposedly enshrined in the Universal Declaration of Human Rights) according to which every family has a right to choose the number of its offspring, and to replace it by "mutual coercion, mutually agreed upon".

Some scholars have argued that over-exploitation of the common resource is by no means inevitable, since the individuals concerned may be able to achieve mutual restraint by consensus. Others have contended that the metaphor is inapposite because its exemplar – unfettered access to common land – did not exist historically, the right to exploit common land being controlled by law. The work of Elinor Ostrom, who received the Nobel Prize in Economics is seen by some economists as having refuted Hardin's claims.^[1] Hardin's views on over-population, along with those of writers like Paul R. Ehrlich have been criticised as simplistic ^[2]

Other criticisms have focused on Hardin's racist and eugenicist views, claiming that his arguments are directed towards forcible population control, particularly for people of colour. ^[3][4]