What is "tragedy of the commons"

n. (context economics politics social criticism English) A situation or type of situation in which a shared resource that has no owner (such as the atmosphere or an ocean) is used in an unmanaged way by a number of participants, resulting in the unintended ruin or total consumption of that resource; the theory that situations of this type are a serious social problem.

The tragedy of the commons is an economic theory of a situation within a shared-resource system where individual users acting independently according to their own self-interest behave contrary to the common good of all users by depleting that resource through their collective action.

The concept and name originate in an essay written in 1833 by the Victorian economist William Forster Lloyd, who used a hypothetical example of the effects of unregulated grazing on common land (then colloquially called "the commons") in the British Isles. The concept became widely known over a century later due to an article written by the ecologist Garrett Hardin in 1968. In this context, commons is taken to mean any shared and unregulated resource such as atmosphere, oceans, rivers, fish stocks, or even an office refrigerator.

The tragedy of the commons is often cited in connection with sustainable development, meshing economic growth and environmental protection, as well as in the debate over global warming. It has also been used in analyzing behavior in the fields of economics, evolutionary psychology, anthropology, game theory, politics, taxation and sociology.

Although commons have been known to collapse due to overuse (such as in over-fishing), many examples exist where communities use common resources prudently without collapse. According to the political economist Elinor Ostrom, although it is often claimed that only private ownership or government regulation can prevent the "tragedy of the commons", it is in the interests of the users of a commons to manage it prudently, and complex social schemes are often devised by them for maintaining common resources efficiently.