Tragedy of the commons

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The Tragedy of the Commons is a type of social trap, often economic, that involves a conflict over finite resources between individual interests and the common good. The term derives originally from a comparison noticed by William Forster Lloyd with medieval village land holding in his 1833 book on population.[1] It was then popularized and extended by Garrett Hardin in his 1968 Science essay "The Tragedy of the Commons."[2] However, the theory itself is as old as Thucydides[3] and Aristotle.[4]

Contents

Garrett Hardin's essay

At the beginning of his essay, Hardin draws attention to problems that cannot be solved by technical means (i.e., as distinct from those with solutions that require "a change only in the techniques of the natural sciences, demanding little or nothing in the way of change in human values or ideas of morality"). Hardin contends that this class of problems includes many of those raised by human population growth and the use of the Earth's natural resources.

To make the case for "no technical solutions", Hardin notes the limits placed on the availability of energy (and material resources) on Earth, and also the consequences of these limits for "quality of life". To maximize population, one needs to minimize resources spent on anything other than simple survival, and vice versa. Consequently, he concludes that there is no foreseeable technical solution to increasing both human populations and their standard of living on a finite planet.

From this point, Hardin switches to non-technical or resource management solutions to population and resource problems. As a means of illustrating these, he introduces a hypothetical example of a pasture shared by local herders. The herders are assumed to wish to maximize their yield, and so will increase their herd size whenever possible. The utility of each additional animal has both a positive and negative component:

  • Positive: the herder receives all of the proceeds from each additional animal.
  • Negative: the pasture is slightly degraded by each additional animal.

Crucially, the division of these costs and benefits are unequal: the individual herder gains all of the advantage, but the disadvantage is shared among all herders using the pasture. Consequently, for an individual herder weighing these, the rational course of action is to add an extra animal. And another, and another. However, since all herders reach the same rational conclusion, overgrazing and degradation of the pasture is its long-term fate. Nonetheless, the rational response for an individual remains the same at every stage, since the gain is always greater to each herder than the individual share of the distributed cost. The overgrazing cost here is an example of an externality.

Because this sequence of events follows predictably from the behaviour of the individuals concerned, Hardin describes it as a tragedy: "the remorseless working of things" (in the sense described by the philosopher Alfred Whitehead).

In the course of his essay, Hardin develops the theme, drawing in examples of latter day "commons", such as the atmosphere, oceans, rivers, fish stocks, National Parks, advertising, and even parking meters. The example of fish stocks had led some to call this the "tragedy of the fishers".[5] A major theme running throughout the essay is the growth of human populations, with the Earth's resources being a general commons (given that it concerns the addition of extra "animals", it is the closest to his original analogy).

The essay also addresses potential management solutions to commons problems including: privatization; polluter pays; regulation. Keeping with his original pasture analogy, Hardin categorises these as effectively the "enclosure" of commons, and notes a historical progression from the use of all resources as commons (unregulated access to all) to systems in which commons are "enclosed" and subject to differing methods of regulated use (access prohibited or controlled). Hardin argues against the reliance on conscience as a means of policing commons, suggesting that this favours selfish individuals over those more far-sighted.

In the context of avoiding over-exploitation of common resources, Hardin concludes by restating Hegel's maxim (which was actually written by Engels), "Freedom is the recognition of necessity." He suggests that "freedom", if interpreted narrowly as simply the freedom to do as one pleases, completes the tragedy of the commons. By recognising resources as commons in the first place, and by recognising that, as such, they require management, Hardin believes that "we can preserve and nurture other and more precious freedoms."

Aside from its subject matter (resource use), the essay is notable (at least in modern scientific circles) for explicitly dealing with issues of morality, and doing so in one of the scientific community's premier journals, Science. Indeed, the subtitle for the essay is "The population problem has no technical solution; it requires a fundamental extension in morality."

Meaning

The metaphor illustrates how free access and unrestricted demand for a finite resource ultimately structurally dooms the resource through over-exploitation. This occurs because the benefits of exploitation accrue to individuals or groups, each of whom is motivated to maximize use of the resource to the point in which they become reliant on it, while the costs of the exploitation are distributed among all those to whom the resource is available (which may be a wider class of individuals than that which is exploiting it). This, in turn, causes demand for the resource to increase, which causes the problem to snowball to the point in which the resource is exhausted.

Like William Lloyd and Thomas Malthus before him, Hardin was primarily interested in population and especially the problem of human population growth. In his essay he also focused on the use of larger (though still limited) resources such as the atmosphere and oceans, as well as pointing out the "negative commons" of pollution (i.e., instead of dealing with the deliberate privatisation of a positive resource, a "negative commons" deals with the deliberate commonisation of a negative cost, pollution).

As a metaphor, the Tragedy of the Commons should not be taken too literally. The phrase is shorthand for a structural relationship and the consequences of that relationship, not a precise description of it. The "tragedy" should not be seen as tragic in the conventional sense, nor must it be taken as condemnation of the processes that are ascribed to it. Similarly, Hardin's use of "commons" has frequently been misunderstood, leading Hardin to later remark that he should have titled his work "The Tragedy of the Unregulated Commons".[citation needed]

The Tragedy of the Commons has particular relevance in analyzing behaviour in the fields of economics, evolutionary psychology, game theory, politics, taxation, and sociology. Some also see it as an example of emergent behaviour, with the "tragedy" the outcome of individual interactions in a complex system.

Controversy

Even today Hardin's essay "The Tragedy of the Commons" is a source of controversy. Some of this stems from disagreement about whether individuals will always behave in the selfish fashion posited by Hardin (see discussion below).

More significantly, controversy has been fueled by the "application" of Hardin's ideas to real situations. In particular, some authorities have read Hardin's work as specifically advocating the privatisation of commonly owned resources. Consequently, resources that have traditionally been managed communally by local organisations have been enclosed or privatised. Ostensibly this serves to "protect" such resources, but it ignores the pre-existing management, often appropriating resources and alienating indigenous (and frequently poor) populations. In effect, private or state use repeatedly resulted in worse outcomes than compared to the previous commons management.[6] As Hardin's essay focuses on resources that are fundamentally unmanaged, rather than communally managed, this application of his ideas is misplaced. Ironically, given his original hypothetical example, this misunderstanding of Hardin's ideas is often applied to grazing lands.

More generally, Hardin made it very clear that usage of public property could be controlled in a number of different ways to stop or limit over-usage. As has been pointed out by Natalie Wanis, Hardin's advocacy of clearly defined property rights has frequently been misread as an argument for privatization, or private property, per se. The opposite situation to a tragedy of the commons is sometimes referred to as a tragedy of the anticommons: a situation where rational individuals (acting separately) collectively waste a given resource by under-utilizing it.

Historical commons

Hardin's essay introduces a hypothetical pasture as an analogy for "commons" in general. In this analogy, herders using the pasture do so on an individualistic basis, with no community management or oversight. However, actual historical commons 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 "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.

These bundles of rights could not be traded or otherwise disposed of, but they applied in a medieval culture that recognized 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., from anywhere on the common. (The form "commons" is plural, and refers to the whole group of individual pieces of common land subject to these effects.)

Historically, most English commons were reserved for their own commoners (meaning members of that parish), whose use was restricted in various ways according to local custom. In response 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.

Modern commons

Situations exemplifying the "tragedy of the commons" include the overfishing and destruction of the Grand Banks, the destruction of salmon runs on rivers which have been dammed (most prominently in modern times on the Columbia River in the NW US, but historically in N Atlantic rivers generally), the devastation of the sturgeon fishery (in modern times especially in Russia, but in historical times in the US as well), and, in terms of water supply, the limited water available in arid regions (e.g., the area of the Aral Sea) and the Los Angeles water system supply, especially at Mono Lake and Owens Lake.

More general examples (some alluded to by Hardin) of potential and actual tragedies include:

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