Game theory | Tragedy of the commons
Tragedy of the commons
In economics and in an ecological context, the tragedy of the commons is a situation in which individual users, who have open access to a resource unhampered by shared social structures or formal rules that govern access and use, act independently according to their own self-interest and, contrary to the common good of all users, cause depletion of the resource through their uncoordinated action in case there are too many users related to the available resources. Central element of the concept originated in an essay written in 1833 by the British economist William Forster Lloyd, who used a hypothetical example of the effects of unregulated grazing on common land, also known as "the commons" (in Anglo-Saxon law) in Great Britain and Ireland. In embryonic form the idea can also be found at Aristotle: "That which is common to the greatest number gets the least amount of care. Men pay most attention to what is their own: they care less for what is common." The theory became widely known as the "tragedy of the commons" after an essay with this title was published in Science written by Garrett Hardin in 1968. It became one of the most cited academic papers ever published and also one of the most heavily criticized, particularly by anthropologists and historians. Hardin, who wrote a total of 350 articles and 27 books, describes in this early essay that common use will only work reasonably satisfactorily as long as the number of man and beast stay well below the carrying capacity of the land. The availability of resources and the amount of people depending on it should therefor be kept in balance. As a punch-line in the article he writes that a freedom to breed is intolerable. As a result of discussions carried out in the decade after publication, Hardin in a talk in the early 80s suggested a better wording of the central idea: "Under conditions of overpopulation, freedom in an unmanaged commons brings ruin to all." In 1991, faced with evidence of historical and existing commons, Hardin retracted his original thesis and wrote "The Tragedy of the 'Unmanaged' Commons". Critical scholars note that although taken as a hypothetical example by Lloyd, the historical demise of the commons of Britain and Europe resulted not from misuse of long-held rights of usage by the commoners, but from the commons' owners enclosing and appropriating the land, abrogating the commoners' rights. Although open-access resource systems may collapse due to overuse (such as in overfishing), many examples have existed and still do exist where members of a community with regulated access to a common resource co-operate to exploit those resources prudently without collapse, or even creating "perfect order". Elinor Ostrom was awarded the 2009 Nobel Memorial Prize in Economic Sciences for demonstrating this concept in her book , which included examples of how local communities were able to do this without top-down regulations or privatization. On the other hand, Dieter Helm argues that these examples are context-specific and the tragedy of the commons "is not generally solved this way. If it were, the destruction of nature would not have occurred." In a modern global economic context, "commons" is taken to mean any open-access and unregulated resource such as the atmosphere, oceans, rivers, ocean fish stocks, or even an office refrigerator. In an anglo-saxon legal context the concept of the commons derive from a centuries old principle that not all land can be in private hands, but certain types of goods should only belong to the society. Here commons is a type of property that is neither private nor public, but rather held jointly by the members of a community in the interest of the community, who govern access and use through social structures, traditions, or formal rules. In environmental science, 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. (Wikipedia).
