Tragedy of the commons
In economics, the tragedy of the commons is the depletion of a shared resource by individuals, acting independently and rationally according to each one's self-interest, despite their understanding that depleting the common resource is contrary to the group's long-term best interests. The concept is often cited in connection with sustainable development, meshing economic growth and environmental protection, as well as in the debate over global warming. "Commons" can include the atmosphere, oceans, rivers, fish stocks, national parks, advertising, and even parking meters. The tragedy of the commons has particular relevance in analyzing behavior in the fields of economics, evolutionary psychology, game theory, politics, taxation, and sociology. Some also see the "tragedy" as an example of emergent behavior, the outcome of individual interactions in a complex system.
History of the idea 
The enclosure movement in England (which led to over 5000 Inclosure Acts between 1750 and 1860) prompted the analysis of this economic principle, probably known to Adam Smith. In 1833 William Forster Lloyd published a pamphlet concerning European land tenure, specifically of herders sharing a common parcel of land, on which they are each entitled to let their cows graze. By this time, the English spinning and cloth-making industry had created an increased demand for wool. In English villages (as with mountain countries in Europe), shepherds had sometimes grazed their sheep in common areas, and sheep ate grass more severely than cows. Overgrazing could result because for each additional sheep, a herder could receive benefits, while the group shared damage to the commons. If all herders made this individually rational economic decision, the common could be depleted or even destroyed, to the detriment of all.
The same concept is sometimes called the "tragedy of the fishers," because fishing too many fish before or during breeding could cause stocks to plummet.
Garrett Hardin's essay 
In 1968, ecologist Garrett Hardin explored this social dilemma in "The Tragedy of the Commons", published in the journal Science. Hardin discussed problems that cannot be solved by technical means, 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 focused on human population growth, the use of the Earth's natural resources, and the welfare state. If individuals relied on themselves and not on the relationship of society and man, Hardin argued that how many children a family would have would not be of public concern. Parents breeding excessively would leave fewer descendants because they would be unable to provide for each child adequately. Such negative feedback is found in the animal kingdom. Hardin says that if the children of improvident parents starved to death, if overbreeding was its own punishment, then there would be no public interest in controlling the breeding of families. Hardin blamed the welfare state for allowing the tragedy of the commons; where the state provides for children and supports overbreeding as a fundamental human right, malthusian catastrophe is inevitable. Hardin lamented this interpretation of the Universal Declaration of Human Rights:
The Universal Declaration of Human Rights describes the family as the natural and fundamental unit of society. [Article 16] It follows that any choice and decision with regard to the size of the family must irrevocably rest with the family itself, and cannot be made by anyone else.
In addition, Hardin also pointed out the problem of individuals acting in rational self interest by claiming that if all members in a group used common resources for their own gain and with no regard for others, all resources would still eventually be depleted. Overall, Hardin argues against relying on conscience as a means of policing commons, suggesting that this favors selfish individuals — often known as free riders — over those who are more altruistic. In the context of avoiding over-exploitation of common resources, Hardin concludes by restating Hegel's maxim (which was quoted by Engels), "freedom is the recognition of necessity." He suggests that "freedom" completes the tragedy of the commons. By recognizing resources as commons in the first place, and by recognizing that, as such, they require management, Hardin believes that humans "can preserve and nurture other and more precious freedoms."
Metaphoric Meaning 
Like William Lloyd and Thomas Malthus before him, Hardin was primarily interested in the problem of human population growth. In his essay, he also focused on the use of larger (though still limited) resources such as the Earth's atmosphere and oceans, as well as pointing out the "negative commons" of pollution (i.e., instead of dealing with the deliberate privatization of a positive resource, a "negative commons" deals with the deliberate commonization of a negative cost, pollution).
As a metaphor, the tragedy of the commons should not be taken too literally. The "tragedy" is not in the word's conventional or theatric sense, nor a condemnation of the processes that lead to it. Similarly, Hardin's use of "commons" has frequently been misunderstood, leading him to later remark that he should have titled his work "The Tragedy of the Unregulated Commons".
The metaphor illustrates the argument that free access and unrestricted demand for a finite resource ultimately reduces the resource through over-exploitation, temporarily or permanently. 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 borne by all those to whom the resource is available (which may be a wider class of individuals than those who are exploiting it). This, in turn, causes demand for the resource to increase, which causes the problem to snowball until the resource collapses (even if it retains a capacity to recover). The rate at which depletion of the resource is realized depends primarily on three factors: the number of users wanting to consume the common in question, the consumptiveness of their uses, and the relative robustness of the common.
Nobel Prize-winning economist Elinor Ostrom and others revisited Hardin's work in 1999. They found the tragedy of the commons not as prevalent or as difficult to solve, since locals have often come up with solutions to the commons problem themselves; when the commons is taken over by non-locals, those solutions can no longer be used. Axelrod contends that even self-interested individuals will often find ways to cooperate, because collective restraint serves both the collective and individual interests.
Hardin's work was also criticised as historically inaccurate in failing to account for the demographic transition, and for failing to distinguish between common property and open access resources. Carl Dahlman argues that commons were effectively managed to prevent overgrazing. Anthropologist G. N. Appell criticized those who cited Hardin to "impos[e} their own economic and environmental rationality on other social systems of which they have incomplete understanding and knowledge."
German historian Joachim Radkau thought Hardin advocates strict management of common goods via increased government involvement or international regulation bodies. An asserted impending "tragedy of the commons" is frequently warned of as a consequence for adopting policies which restrict private property and espouse expansion of public property.
Allan Savory argues that Hardin misunderstood ecological elements. In the absence of a predator to modify herd behavior, grasses fail to grow, even in moist temperate climates, if overgrazed, leading to the perceived tragedy. Rotating grazers rapidly from one small paddock to another within a larger range according to the life cycle of the browsed vegetation can ameliorate the overgrazing problem. Moreover, rangelands in brittle climates can be ruined by undergrazing as well as overgrazing. They advocate timed mob grazing, which occurs naturally in the presence of top predators.
Modern commons 
The tragedy of the commons can be considered in relation to environmental issues such as sustainability. The commons dilemma stands as a model for a great variety of resource problems in society today, such as water, forests, fish, and non-renewable energy sources such as oil and coal.
Situations exemplifying the "tragedy of the commons" include the overfishing and destruction of the Grand Banks, the destruction of salmon runs on rivers that have been dammed – most prominently in modern times on the Columbia River in the Northwest United States, and historically in North Atlantic rivers – the devastation of the sturgeon fishery – in modern Russia, but historically in the United States 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.
Other situations exemplifying the "tragedy of the commons" include congestion caused by driving cars. There are many negative externalities of driving; these include pollution, carbon emissions, and traffic accidents. For example, every time 'Person A' gets in a car, it becomes more likely that 'Person Z' – and millions of others – will suffer in each of those areas.
Still other examples include the US Federal budget. The federal budget being analogous to a common pasture on which 535 congressional cows graze.
More general examples (some alluded to by Hardin) of potential and actual tragedies include:
- Planet Earth ecology
- Uncontrolled human population growth leading to overpopulation.
- Air, whether ambient air polluted by industrial emissions and cars among other sources of air pollution, or indoor air.
- Water – Water pollution, water crisis of over-extraction of groundwater and wasting water due to overirrigation
- Forests – Frontier logging of old growth forest and slash and burn
- Energy resources and climate – Environmental residue of mining and drilling, Burning of fossil fuels and consequential global warming
- Animals – Habitat destruction and poaching leading to the Holocene mass extinction
- Oceans – Overfishing
- Publicly shared resources
- Radio frequencies – Unlicensed frequencies used for wireless communications, especially 802.11 a/b/g in the U.S., detailed under Part 15 (FCC rules) would be vulnerable to the overuse of high power transmitters, especially overdriven transmitters with dirty signal profiles, and especially when combined with omnidirectional antennas, had the FCC not mandated maximum transmission power for each class of device and limitations on their spectral profile.
- Spam email degrades the usefulness of the email system and increases the cost for all users of the Internet while providing a benefit to only a tiny number of individuals.
- Vandalism and littering in public spaces such as parks, recreation areas, and public restrooms.
- Knowledge commons encompass immaterial and collectively owned goods in the information age.
- Freeways experience heavy traffic due to overuse
Modern solutions 
Articulating solutions to the tragedy of the commons is one of the main problems of political philosophy. In absence of enlightened self-interest, some form of authority or federation is needed to solve the collective action problem. In a typical example, governmental regulations can limit the amount of a common good available for use by any individual. Permit systems for extractive economic activities including mining, fishing, hunting, livestock raising and timber extraction are examples of this approach. Similarly, limits to pollution are examples of governmental intervention on behalf of the commons. Alternatively, resource users themselves can cooperate to conserve the resource in the name of mutual benefit. Another solution for some resources is to convert common good into private property, giving the new owner an incentive to enforce its sustainability.
An opposing idea, used by the United Nations Moon Treaty, Outer Space Treaty and Law of the Sea Treaty as well as the UNESCO World Heritage Convention involves the international law principle that designates some areas or resources the Common Heritage of Mankind.
Libertarians and classical liberals often cite the tragedy of the commons as an example of what happens when Lockean property rights to homestead resources are prohibited by a government. These people argue that the solution to the tragedy of the commons is to allow individuals to take over the property rights of a resource, that is, privatizing it. In 1940 Ludwig von Mises wrote concerning the problem:
If land is not owned by anybody, although legal formalism may call it public property, it is used without any regard to the disadvantages resulting. Those who are in a position to appropriate to themselves the returns — lumber and game of the forests, fish of the water areas, and mineral deposits of the subsoil — do not bother about the later effects of their mode of exploitation. For them, erosion of the soil, depletion of the exhaustible resources and other impairments of the future utilization are external costs not entering into their calculation of input and output. They cut down trees without any regard for fresh shoots or reforestation. In hunting and fishing, they do not shrink from methods preventing the repopulation of the hunting and fishing grounds.
An objection to the privatization approach is that many commons (such as the ozone layer or global fish populations) would be extremely difficult or impossible to privatize.
Psychologist Dennis Fox used a number, what is now termed "Dunbar's number", to take a new look at the tragedy of the commons. In a 1985 paper titled "Psychology, Ideology, Utopia, & the Commons", he stated "Edney (1980, 1981a) also argued that long-term solutions will require, among a number of other approaches, breaking down commons into smaller segments. He reviewed experimental data showing that cooperative behavior is indeed more common in smaller groups. After estimating that "the upper limit for a simple, self-contained, sustaining, well-functioning commons [sic] may be as low as 150 people" (1981a, p. 27).
Costa Rica has successfully advanced the growth of its ecotourism business by taking account of, and pricing for, the environmental business services consumed by pollution. The Coast Salish managed their natural resources in a place-based system in which families were responsible for looking after a place and its resources. Access to food was the major source of wealth and the empowerment of generosity was highly valued, so it made sense for them to take care of the resources.
The "Coasian" solution to the problem is also a popular one, whereby the people formerly using the common each gain their own individual part of it instead — so it is no longer a common — and do not have to support one another so as not to deplete 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. He framed this prescription in terms of needing to restrict the "reproductive right" in order to safeguard all other rights. Only one large country has adopted this policy, the People's Republic of China. In the essay, Hardin had rejected education as an effective means of stemming population growth. Since that time, it has been shown that increased educational and economic opportunities for women correlates well with reduced birthrates in most countries, as does economic growth in general. However, given the nature of the problem as a limit to a given common resource, economic growth resulting in a higher per capita use of the resource may more than offset the decreased population growth's effect on total resource consumption. Note, however, that this now becomes a problem of economic expectations of a given population, and the problem of birth regulation appears to be eliminated.
One solution to such problem globally has been proposed by the International Simultaneous Policy Organization in the form of their global Simultaneous policy campaign. The campaign works by voters in each country withholding their votes from anyone but those politicians who have signed the simultaneous policy pledge. When a tipping point of serving politicians worldwide has been achieved, simultaneous policy can be negotiated between nations and then implemented.
Application to evolutionary biology 
The tragedy of the commons is referred to in studies of evolutionary biology, social evolution, sociobiology and behavioral ecology. A tragedy of the commons is brought about by selfish individuals whose genes for selfish behaviour would therefore come to predominate, so the metaphor cannot explain how altruism arises. It is easy to see how cooperation can be evolved between related individuals through kin selection, but in order understand cooperation between unrelated individuals mechanisms which confer direct benefits to the actor must be considered such as by-product benefits and reciprocal altruism.
The idea has also been applied to areas such as the evolution of virulence or sexual conflict, where males may fatally harm females when competing for matings. It is also raised as a question in studies of social insects, where scientists wish to understand why insect workers do not undermine the "common good" by laying eggs of their own and causing a breakdown of the society.
The idea of evolutionary suicide, where adaptation at the level of the individual causes the whole species or population to be driven extinct, can be seen as an extreme form of an evolutionary tragedy of the commons.
The commons dilemma 
The commons dilemma is a specific class of social dilemma in which people's short-term selfish interests are at odds with long-term group interests and the common good. In academia, a range of related terminology has also been used as shorthand for the theory or aspects of it, including resource dilemma, take-some dilemma, and common pool resource.
Commons dilemma researchers have studied conditions under which groups and communities are likely to under- or over-harvest common resources in both the laboratory and field. Research programs have concentrated on a number of motivational, strategic, and structural factors that might be conducive to management of commons.
In game theory, which constructs mathematical models for individuals' behavior in strategic situations, the corresponding "game", developed by the ecologist Garrett Hardin, is known as the Commonize Costs — Privatize Profits Game (CC–PP game).
Psychological factors 
Kopelman, Weber, & Messick (2002), in a review of the experimental research on cooperation in commons dilemmas, identify nine classes of independent variables that influence cooperation in commons dilemmas: social motives, gender, payoff structure, uncertainty, power and status, group size, communication, causes, and frames. They organize these classes and distinguish between psychological individual differences (stable personality traits) and situational factors (the environment). Situational factors include both the task (social and decision structure) and the perception of the task. Another important factor—that is not covered in the review by Kopelman et all (2002) -- is culture. Empirical findings support the theoretical argument that the cultural group is a critical factor that needs to be studied in the context of situational variables (Gelfand & Dyer, 2000). Rather than behaving in line with economic incentives, people are likely to approach the decision to cooperate with an appropriateness framework (Weber et al, 2004). An expanded, four factor model of the Logic of Appropriateness (Kopelman, 2009; Myers & Kopelman, 2012), suggests that the cooperation is better explained by the question: "What does a person like me (identity) do (rules) in a situation like this (recognition) given this culture (group)?"
Tragedy of the Commons in Relation to Self Control 
A self control choice situation involves making a choice between a small proximal reinforcer and a larger but more distant reinforcer (Rachlin 1974). This relates to the tragedy of the commons because it deals with choosing short term interests versus long term interests. Specifically in this situation, when a person chooses their own short term interests, it affects society as a whole negatively. For example, when a person decides to smoke in a public area, they are pleasing themselves in the short run but the long term effects affect both other people through second hand smoking as well as their own health. This demonstrates the principle of the tragedy of the commons. In order to overcome this tragedy, people can use the precommitment strategy: the individual makes a decision in advance, which is difficult or impossible to change at a later time (Rachlin & Green1972). For example, society can pass legislation that makes it illegal to smoke in public areas or increase the tax on cigarettes in order to make the decision to smoke in public places difficult. The principle of delay discounting relates to the tragedy of the commons because it deals with having to choose between an immediate reinforcer as opposed to a more distant reinforcer. Another concept that furthers our understanding of people’s decision making is social discounting. Social discounting not only takes into account an individual’s choice between the immediate or delayed reinforcer but also deals with the choice to benefit someone else who is closely tied to their social network. In Brian Jones and Howard Rachlin’s study on social discounting they found that majority of the participants were willing to give up a hypothetical amount of money so that they could give $75 to another person (Jones & Rachlin, 2005). These results showed that most people are willing to be generous to the people they are socially closest to, which suggests that altruism may be closely related to social discounting. Dennis Fox goes more in depth about the social values and social structures of society and how it relates to the tragedy of the commons in his paper Psychology, Ideology, Utopia & the Commons.
Strategic factors 
Strategic factors also matter in commons dilemmas. One often-studied strategic factor is the order in which people take harvests from the resource. In simultaneous play, all people harvest at the same time, whereas in sequential play people harvest from the pool according to a predetermined sequence — first, second, third, etc. There is a clear order effect in the latter games: the harvests of those who come first — the leaders — are higher than the harvest of those coming later — the followers. The interpretation of this effect is that the first players feel entitled to take more. With sequential play, individuals adopt a first come-first served rule, whereas with simultaneous play people may adopt an equality rule. Another strategic factor is the ability to build up reputations. Research[by whom?] found that people take less from the common pool in public situations than in anonymous private situations. Moreover, those who harvest less gain greater prestige and influence within their group.
Structural factors 
Much research has focused on when and why people would like to structurally rearrange the commons to prevent a tragedy. Hardin stated in his analysis of the tragedy of the commons that "Freedom in a commons brings ruin to all." One of the proposed solutions is to appoint a leader to regulate access to the common. Groups are more likely to endorse a leader when a common resource is being depleted and when managing a common resource is perceived as a difficult task. Groups prefer leaders who are elected, democratic, and prototypical of the group, and these leader types are more successful in enforcing cooperation. A general aversion to autocratic leadership exists, although it may be an effective solution, possibly because of the fear of power abuse and corruption.
The provision of rewards and punishments may also be effective in preserving common resources. Selective punishments for overuse can be effective in promoting domestic water and energy conservation — for example, through installing water and electricity meters in houses. Selective rewards work, provided that they are open to everyone. An experimental carpool lane in the Netherlands failed because car commuters did not feel they were able to organize a carpool. The rewards do not have to be tangible. In Canada there is a movement to put "smiley faces" on electricity bills if you are below the average for your class. Much field research on commons dilemmas has combined solutions obtained in experimental research. Elinor Ostrom, who was awarded 2009's Nobel Prize of Economics for her work on the issue, and her colleagues looked at how real-world communities manage communal resources, such as fisheries, land irrigation systems, and farmlands, and they identified a number of factors conducive to successful resource management. One factor is the resource itself; resources with definable boundaries (e.g., land) can be preserved much more easily. A second factor is resource dependence; there must be a perceptible threat of resource depletion, and it must be difficult to find substitutes. The third is the presence of a community; small and stable populations with a thick social network and social norms promoting conservation do better. A final condition is that there be appropriate community-based rules and procedures in place with built-in incentives for responsible use and punishments for overuse.
Related outcomes 
Tragedy of the commons is one of four outcomes:
|Private ownership||Common ownership|
|Bad outcome/tragedy||Tragedy of the anticommons||Tragedy of the commons|
|Good outcome/cornucopia||Successful capitalism||Comedy of the commons|
The prevalent outcome depends on the details of the situation. The opposite outcome to the tragedy is the "comedy of the commons" or "inverse commons", in which network effects or other causes enhance the value of rivalrous resources because of the lack of regulation or private ownership.
See also 
- Radkau, Joachim. Nature and Power. A Global History of the Environment. Cambridge University Press. 2008.
- Samuel Bowles: Microeconomics: Behavior, Institutions, and Evolution, Princeton University Press, pp. 27–29 (2004) ISBN 0-691-09163-3
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- Hardin, G. (1968-12-13). "The Tragedy of the Commons". Science (AAAS) 162 (3859): 1243–1248. doi:10.1126/science.162.3859.1243. PMID 5699198. Retrieved 2011-09-04. "it is the role of education to reveal to all the necessity of abandoning the freedom to breed. Only so, can we put an end to this aspect of the tragedy of the commons."
- "The Universal Declaration of Human Rights". 10 December 1948. Retrieved 4 September 2011.
- United Nations. Dept. of Economic and Social Affairs. Population Division (2004). Levels and trends of contraceptive use as assessed in 2002. United Nations Publications. p. 126. ISBN 92-1-151399-5. "some have argued that it may be inferred from the rights to privacy, conscience, health and well-being set forth in various United Nation's conventions [...] Parents have a basic human right to determine freely and responsibly the number and spacing of their children (United Nations, 1968)"
- "Will commons sense dawn again in time? | The Japan Times Online". Search.japantimes.co.jp. 2006-07-26. Retrieved 2012-06-22.
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- Ostrom, Elinor, Joanna Burger, Christopher B. Field, Richard B. Norgaard, and David Policansky (1999): Revisiting the Commons: Local Lessons, Global Challenges, in: Science, Vol. 284, 9 April, pp. 278-282.
- "Ostrom 'revisits the commons' in 'Science'".
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- Kopelman, S., Weber, M, and Messick, D. (2002). "Factors Influencing Cooperation in Commons Dilemmas: A Review of Experimental Psychological Research". In E. Ostrom et al., (Eds.) The Drama of the Commons. Washington DC: National Academy Press. Ch. 4., 113–156.
- Kopelman, S. (2009). "The effect of culture and power on cooperation in commons dilemmas: Implications for global resource management". Organization Behavior and Human Decision Processes, 108, 153–163. doi:10.1016/j.obhdp.2008.06.004.
- Ostrom, E. (1990). Governing the commons: The evolution of institutions for collective action. Cambridge: Cambridge University Press.
- Bryan Jones, B. J., and Howard Rachlin, H. R. (2006). "Social discounting". Psychological Science 17(4), 283–286. Retrieved from http://evolution.binghamton.edu/evos/wp-content/uploads/2009/08/Rachlin1.pdf.
- Rachlin, H. (1974). "Self-control". Behaviorism 2, 94–107.
- Rachlin, H., and Green, L. (1972). "Commitment, choice, and self-control". Journal of the Experimental Analysis of Behavior 17, 15–22.
- Van Vugt, M. (2001). "Community identification moderating the impact of financial incentives in a natural social dilemma". Personality and Social Psychology Bulletin 27: 1440–1449.
- Van Vugt, M. (2009). "Triumph of the commons: Helping the world to share". New Scientist (2722): 40–43.
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- Weber, M., Kopelman, S., and Messick, D. (2004). "A conceptual review of decision making in social dilemmas: applying the logic of appropriateness". Personality and Social Psychology Review 8 (3), 281–307.
Further reading 
- Hardin, G. (1994). "The Tragedy of the Unmanaged Commons". Trends in Ecology & Evolution 9 (5): 199. doi:10.1016/0169-5347(94)90097-3.
- Ostrom, E. (1990). Governing the commons: The evolution of institutions for collective action. Cambridge: Cambridge University Press.
- Thinking Strategically: The Competitive Edge in Business, Politics, and Everyday Life by Avinash Dixit and Barry Nalebuff
- Kopelman, S., Weber, M, & Messick, D. (2002). Factors Influencing Cooperation in Commons Dilemmas: A Review of Experimental Psychological Research. In E. Ostrom et al., (Eds.) The Drama of the Commons. Washington DC: National Academy Press. Ch. 4., 113-156
|Look up tragedy of the commons in Wiktionary, the free dictionary.|
- Original article by Garrett Hardin from Science (journal)
- The Digital Library of the Commons
- The Myth of the Tragedy of the Commons by Ian Angus
- Global Tragedy of the Commons by John Hickman and Sarah Bartlett
- Tragedy of the Commons Explained with Smurfs by Ryan Somma