Tragedy of the commons
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The tragedy of the commons is a metaphor used to illustrate the conflict between individual interests and the common good. The term was popularized by Garrett Hardin in his 1968 Science article "The Tragedy of the Commons."
Hardin uses the example of English Commons, shared plots of grassland used in the past by all livestock farmers in a village. Each farmer keeps adding more livestock to graze on the Commons, because it costs him nothing to do so. In a few years, the soil is depleted by overgrazing, the Commons becomes unusable, and the village perishes. Hardin actually misunderstood how commons were managed in England and elsewhere (see below for details), but this may not affect the greater significance of his argument, which pertains primarily to truly open access commons such as the sea and the atmosphere.
The cause of any tragedy of the commons is that when individuals use a public good, they do not bear the entire cost of their actions. If each seeks to maximize individual utility, he ignores the costs borne by others. This is an example of an externality. The best (non-cooperative) short-term strategy for an individual is to try to exploit more than his share of public resources. Assuming a majority of individuals follow this strategy, the theory goes, the public resource gets overexploited.
The tragedy of the commons is a source of intense controversy, precisely because it is unclear whether individuals will or will not always follow the overexploitation strategy in any given situation, and especially because Hardin had a very poor understanding of how traditional commons were managed. Experiments have indicated that individuals do tend to behave in this way, when the common is unregulated, but historically, most commons have been regulated by communities, and the more use-pressure a common is under, the more heavily regulated its use would be. Hardin's misunderstanding of the traditions of commonland and resource management, however, has been widely influential and has caused a great deal of trouble for those who wish to advocate regulated communal land use, as opposed to enclosure and privatisation (which has historically been associated with the alienation of resources from poorer people).
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Historical background
Hardin begins his essay with a discussion of the concept of a "commons", which he draws largely from the history of common land use in England, and other parts of North Western Europe. However, these historical commons to which he refers were not public land and most were not open to the access of all — the public at large had very limited rights (e.g. passing drovers could lease grazing for "thistle rent"). Only those locals who were also "commoners" had access to a bundle of rights; each commoner then had an interest in his own rights, but the common itself was not property.
Under many modern understandings of property, e.g. in the USA, the bundles of rights would not have been "property" either, since they could not be traded or otherwise disposed of. However these commoner's rights applied in a medieval culture which did recognise inalienable property (e.g. entailed inheritances), so under this system the bundles of rights were considered property.
In a traditional English village these rights provided commoners with rights of grazing, gathering fuel wood non-destructively "by hook or by crook", etc. (the form "commons" is plural, and refers to the whole group of commons subject to these effects).
Consider an area used for grazing (among other purposes — it could be "Lammas Land", used for private crops in season) that can support 50 cattle indefinitely, a population of 25 peasant householders who keep cattle among a range of subsistence activities, and that each peasant can advantageously graze and profit from 2 cattle indefinitely. By grazing one extra cow, a peasant can make roughly 1/2 extra "profit" at a "cost" of only 1/50. Thus each peasant is logically tempted to keep adding cattle beyond the capacity of the common to sustain them all optimally. Where the grazing area could sustain 50 cattle indefinitely, this increased grazing load could diminish or even destroy the ability of the land to sustain any cattle, at least until it has recovered. (A tragedy of the commons can occur even without complete and permanent destruction of a resource, although such things as overfishing can indeed do that.)
Though this metaphor is not an accurate description of how the system worked during most of its history, it serves here for purposes of illustration. Historically, few English commons were ever truly public but was reserved for its own commoners, whose own use was also restricted in various customary ways (which differed from place to place). In reponse to overgrazing, for example, a common would be "stinted", that is, a limit would be put on the number of animals each commoner was allowed to graze. This stint might be related to the ownership of a commonable cottage, or to the amount of land owned in the open fields. These regulations were responsive to demographic and economic pressure; rather than let the commons be degraded, access was usually restricted even further. By the time of parliamentary enclosure, in many manors in southern England few labourers and poorer people held common grazing rights; enclosure, however, did have an impact on smaller landholders who supported their farming through use of common grazing and other resources. While historians continue to debate the significance and impact of enclosure on small landholders and labouring people in England, they agree that there is no evidence that commonland use was itself unsustainable.
Modern equivalents
Modern equivalents include:
- Uncontrolled population growth.
- Depleting biodiversity.
- Burning of fossil fuels.
- Pollution of waterways and the atmosphere.
- Logging of forests.
- Overfishing of the oceans.
- Private vehicles jamming public roadways.
- Tossing of trash out of automobile windows (littering).
- Graffiti
- Poaching.
- E-mail spamming.
- Abuse of free Wi-Fi in coffeeshops by not buying beverages. [1] (http://wifinetnews.com/archives/005325.html)
The contribution of each actor is minute, but summed over all actors, these actions degrade the resource.
Possible solutions to the 'tragedy'
The tragedy of the commons can be seen as a collective prisoner's dilemma. Individuals within a group have two options: cooperate with the group or defect from the group. Cooperation happens when individuals agree to protect a common resource to avoid the tragedy. By cooperating, every individual agrees not to seek more than his share. Defection happens when an individual decides to use more than his share of a public resource.
Game theory shows that cooperation maximizes every individual's benefit in the long run (i.e. the 'tragedy' does not happen, the commons are preserved and can be used indefinitely), while defection maximizes an individual's benefit in the short run at the expense of destroying it in the long run (i.e. the 'tragedy' happens and all individuals lose). Thus, a possible solution to the tragedy of the commons is to simply have a group of far-sighted individuals who can see their long-term interest.
Articulating solutions to the tragedy of the commons is also one of the main problems of political philosophy. Many such solutions involve enforcement of conservation measures by an authority, which may be an outside agency or selected by the resource users themselves, who agree to cooperate to conserve the resource. Another frequently-proposed solution is to convert each common into private property, giving the owner of each an incentive to enforce its sustainability. Effectively, this is what took place in the English "Enclosure of the Commons"; this case highlights the effects of hidden wealth transfer in privatization, if no or inadequate matching compensation occurs. Moreover, as demonstrated by recent conflicts over logging, snow cover and water resources in the Upper Rio Grande watershed, there are questions about whether individual ownership does provide an incentive to enforce its sustainability, particularly if the property is not looked on as a long term investment. Increasingly, many agrarian studies scholars advocate studying traditional commons management systems, to understand how common resources can be protected without alienating those whose livelyhoods depend upon them.
A popular solution to the problem is also the "Coasian" one, where the individuals using the commons make payments to one another in exchange for not overusing the resource.
In Hardin's essay, he proposed that the solution to the problem of overpopulation must be based on "mutual coercion, mutually agreed upon" and result in "relinquishing the freedom to breed." Hardin discussed this topic further in a 1979 book, Managing the Commons, co-written with John A. Baden[2] (http://www.ecobooks.com/commons.htm).
See also
External links and references
- The original article by Garrett Hardin and responses to it (http://www.sciencemag.org/sciext/sotp/commons.shtml) From the Science Magazine website.
- "Global Tragedy of the Commons at COP 6" (http://www.greens.org/s-r/24/24-26.html) by John Hickman and Sarah Bartlett
- What about the "Tragedy of the Commons"? Surely communal ownership will lead to overuse and environmental destruction? (http://www.infoshop.org/faq/secI6.html) -- Libertarian Socialist critique of the "Tragedy of the Commons"
- "The Tragedy of the Advertising Commons" (http://www.marketingprofs.com/4/syrett5.asp) by Matthew Syrett
- A documentary was broadcast on cable TV in February 2005 that illustrated the "Tragedy of the Commons."
- Slate: "Awareness bracelets and the tragedy of the commons" (http://slate.msn.com/id/2113014/) by Timothy Noah.
- The Nuts Game: A Concise Commons Dilemma Analog (http://www.g-r-e-e-d.com/Nuts%20Game.htm)
- Property Rights & the Tragedy of the Commons - Fishing Game (http://64.233.187.104/search?q=cache:oZV5Qfj30jAJ:www.fraserinstitute.ca/teachercentre/pdf/Property_Rights.pdf+%22tragedy+of+the+commons%22+%2Bexperiments&hl=en) Instruction on performing a classroom experiment to illustrate the behavior
- The Management of Common Land in North West Europe (http://www.h-net.org/reviews/showrev.cgi?path=8751056723123) edited by Martina de Moor, Leigh Shaw-Taylor, and Paul Warde.de:Tragik der Allmende