The Tragedy of the Commons

This article was written by Garret Hardin the the journal Science in 1968. The article describes a dilemma in which multiple individuals acting independently in their own self-interest can ultimately destroy a shared limited resource even where it is clear that it is not in anyone's long term interest for this to happen.

Wiesner and York had concluded in a thoughtful article on the fate of nuclear war that " Both sides in the arms race are confronted by the dilemma of steadily increasing military power and steadily decreasing national security. It is our considered professional judgment that this dilemma has no technical solution. If the great powers continue to look for solutions in the area of science and technology only, the result will be to worsen the situation." A technical solution as defined by the author is one that requires 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. The author wants the reader to discuss the presence of "the no technical solution possible" class of problems. He explains that a game of tic-tac-toe can be such a problem given the opponent understands the game perfectly and game theory predicts in that case there is no way to beat him. The author also states the population problem being on of this class. He says that the people who are trying to find a solution to overpopulation look for alternatives to relinquish any priviliges the population enjoys now which are not sustainable.

The author mentions the famous Bentham's goal of " the greates good for the greatest number". The fact that two variables can't be maximized together as proven by Von Neumann and Morgenstern and which appears to be implicit in theory of partial differentiation puts a deathnail to Bentham's goal. He also mentions that the goal can't be realised due to biological/energy limitations. He even says that if provided with an infinite source of energy, the problem just reverses signs and doesn't cease to exist.

From this point, the author 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 is 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 the rational course of action is to continue to add additional animals to his or her herd. 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".

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". A major theme running throughout the essay is the growth of human populations, with the Earth's resources being a general commons.

The essay also addresses potential management solutions to commons problems including privatizatiion, polluter pays, and regulation. Keeping with his original pasture analogy, Hardin categorises these as effectively the "enclosure" of commons, and notes an 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 in which access is prohibited or controlled. Hardin argues against relying on conscience as a means of policing the commons, suggesting that this favours selfish individuals – often known as free riders – over those who are more altruistic. 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."