The Tragedy of the Commons

The Tragedy of the Commons is a 1968 paper by biologist Garrett Hardin. The paper was meant to focus attention on the lack of technical solutions to arrest overpopulation, but its explanation for why commonly-held resources such as groundwater, grazing land, and fisheries are prone to inevitably degrade has influenced the development of environmental and economic policies for resource management.

Garret Hardin's Essay

The Tragedy of the Commons addresses competing viewpoints about how to deal practically with overpopulation. Hardin's explanation of why commonly-held resources degrade was used in the paper as an intellectual exercise to refute the "invisible hand theory" of population control. Hardin wanted to disprove the contention of economist Adam Smith and his disciples that rational decisions made to promote one's self-interest will inevitably be what is best for the common good. 

Hardin used cattle grazing on common property as an example of a situation where the cumulative effects of individual decisions result in degradation. Because each cattleman benefits from increasing the size of his herd on the lot, and he feels only a fraction of the negative effects of overgrazing, any rational cattleman would increase the size of his herd. Hence, overgrazing is inevitable, and freedom of the commons in a world that is limited "brings ruin to all." 

It should be noted that the theory is relatively simplistic and abstract and it would be difficult to find any resource, be it fisheries or forests, that is completely unregulated in any part of the world. However, the theory depicts what is likely to happen should regulations be ineffective in controlling the behavior of rational individuals who choose to promote their self-interest.


Modern Commons

The logic presented in the tragedy of the commons applies to nearly every commonly held property. Below are some common examples. 

Air and Water Pollution
Each acting unit, be it a person, company, or factory, receives one hundred percent of the benefits of easy disposal of waste into air or bodies of water but only incurs a fraction of the negative effects of the pollution. When governments do not place limits on an acting unit's pollution releases, the actor benefits economically from free disposal of waste. It is therefore necessary for governments to regulate pollution, providing appealing incentives to prevent pollution or imposing penalties should pollution occur. 

National Parks
The parks are open to everyone without limits on visitation, but the parks themselves are a limited common resource. As the number of visits increases, degradation of the parks becomes more probable. The finite number of parks, coupled with increasing visitation and population growth, makes conservation efforts difficult. 

In 1992, the Canadian Government issued a moratorium on cod fishing in the once preeminent cod waters off the coast of Newfoundland. Nearly 40,000 jobs had been lost due to overfishing by a variety of fishing enterprises from many countires (#Mason, 2002). The government had placed few restrictions and individual actors had little short-term interest in lowering fish catches. The fishery was devastated and is still under the moratorium. Please see the articles below for details on the collapse. 

Unfortunately, mismanagement and overfishing is prevalent in numerous fisheries. Over 90% of the original stock of large predator fish including bluefin tuna, shark, and cod have disappeared (#Conservation International). The global fishing fleet is two and a half times greater than what waters can realistically support, with 52% of the world's fisheries fully exploited and 24% overexploited, depleted, or recovering from depletion (#WWF). 

Forests throughout the world are overexploited and in many countries, especially those lacking resources to make forest protection a priority, the authorities are unable to manage them sustainably.


Modern Solutions

Privatizing Property
By making resources private property, owners will have an incentive to keep others off their property, which would limit the number of users, and to use the property sustainably so they can benefit from it in the future. This approach is plausible as long as the property is not too large, which makes it difficult to control trespassing (#Feeny, et al, 1990).

Regulating Public Property
Another theoretical solution to avoid degradation of resources is to "keep them as public property, but allocate the right to enter them" (#Hardin, 1968). Hardin allows that there are many ways to allocate access - basis of merit, first come first serve, auction system - and while these may not be perfect or even desired, they are necessary to ensure the resources' sustainability. 

Holding Property Communally
For smaller resources, such as inshore fisheries, shellfish beds, range lands, and some forests, holding the property communally and allocating use through the community can be feasible (#Feeny, et al, 1990). This was not considered by Hardin and communal property is rare around the world. If  everyone in a community has an equal right to the resource and the community's population grows, the resource will be brought under increasing strain.

External Links

  • the Tragedy of the Commons. On the Commons (formerly Tomales Bay Institute) is a network of citizens and organizations exploring new ways to achieve social justice, environmental harmony and democratic participation at all levels of soc



De Young, R. (1999). "Tragedy of the Commons." In D. E. Alexander and R. W. Fairbridge Eds.Encyclopedia of Environmental Science. Hingham, MA: Kluwer Academic Publishers. 

Feeny, David Fikrit Berkes, Bonnie J. McCay, and James M. Atcheson. "The Tragedy of the Commons: Twenty-Two Years Later." Human Ecology 18, 1990.

Hardin, Garrett. "Tragedy of the Commons"Science 162: 1243-1248.

Hardin, Garrett. Exploring New Ethics for Survival: The Voyage of the Spaceship Beagle, The Viking Press, New York, 1972.

Conservation International. Accessed 1-17-07.

Mason, Fred. "The Newfoundland Cod Stock Collapse"The Electronic Green Journal, 2002.

Myers, Ransom A., Jeffery Hutchings, and Nicholas Barrowman. "Why do Fish Stocks Collapse? The Example of Cod in the AtlanticEcological Applications 1, p91-106, 1997.

Roy, Noel. "The Atlantic Canada Resource Management Catastrophe: What Went Wrong and What Can We Learn?"The Canadian Journal of Economics 29, pS139-S144, 1996.

WWF. Accessed 1-17-07.

Tragedy of the Commons graph retrieved from the Rochester University Economics Department.