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Tragedy of the Commons

The concept of the Tragedy of the Commons is extremely important for understanding the degradation of our environment. The concept was clearly expressed for the first time by Garrett Hardin in his now famous article in Science in 1968, which is "widely accepted as a fundamental contribution to ecology, population theory, economics and political science." Hardin: University of California Santa Barbara.

garrett hardin in 1963
Garrett Hardin, the author of Tragedy of the Commons, in 1963.
From The Garrett Hardin Society.

The Basic Idea

If a resource is held in common for use by all, then ultimately that resource will be destroyed. "Freedom in a common brings ruin to all." To avoid the ultimate destruction, we must change our human values and ideas of morality.

  1. "Held in common" means the resource is owned by no one, or owned by a group, all of whom have access to the resource.

  2. "Ultimately" means after many years, maybe centuries. The time interval is closely tied to population increase of those who have access to the resource. The greater the number of people using a resource, the faster it is destroyed. Thus the Tragedy of the Commons is directly tied to over population.

  3. The resource must be available for use. Iron in earth's core is held in common, but it is inaccessible, and it will not be destroyed.

  4. Resources held by individuals, even if the individual destroys the resource, is not an example of the Tragedy of the Commons.

  5. Hardin used the word "tragedy" as the philosopher Whitehead used it:

    "The essence of dramatic tragedy is not unhappiness. It resides in the solemnity of the remorseless working of things." He [Whitehead] then goes on to say, "This inevitableness of destiny can only be illustrated in terms of human life by incidents which in fact involve unhappiness. For it is only by them that the futility of escape can be made evident in the drama."
    Hardin (1968)

    Once the stage is set in a dramatic tragedy, there is no escape from the unhappy ending.

  6. Note that the tragedy does not need to follow from greed. In the example below, we all breath the air. This degrades the common resource: air. But we breath not because we are greedy, but because we want to live. Any sustained increase of population in a finite biosystem ends in tragedy.

    In brief, tragedy is logically dependent only on the assumption that there is steady growth in the use of land or resources within any finite ecosystem; it is not logically dependent on the conventions of any specific political and economic system.

    From A General Statement of Hardin's Tragedy of the Commons by Herschel Elliott.

  7. We can avoid tragedy only by altering our values, by changing the way we live. There is no technical solution.

    The general statement of the tragedy of the commons demonstrates that an a priori ethics constructed on human-centered, moral principles and a definition of equal justice cannot prevent and indeed always supports growth in population and consumption. Such growth, though not inevitable, is a constant threat. If continual growth should ever occur, it eventually causes the breakdown of the ecosystems which support civilization. ... Specifically, Hardin's thought experiment with an imaginary commons demonstrates the futility -- the absurdity -- of much traditional ethical thinking.
    From A General Statement of Hardin's Tragedy of the Commons by Herschel Elliott.

    We will not delve further into the ethical implications. They are profound and far reaching.

Garrett rephrased his idea in 1985:

As a result of discussions carried out during the past decade I now suggest a better wording of the central idea:
Under conditions of overpopulation, freedom in an unmanaged commons brings ruin to all.

From Hardin (1985) An Ecolate View of the Human Predicament.

Examples of Common Resources

  1. Air. No one owns the air, it is available for all to use, and its unlimited use leads to air pollution.
  2. Water. Water in the seas, estuaries, and the ocean is a common resource. But, water in lakes and rivers is often owned by cities, farmers, or others, especially in the western US.
  3. Fish of the sea.
    Hardin writes that In 1625, the Dutch scholar Hugo Grotius said, "The extent of the ocean is in fact so great that it suffices for any possible use on the part of all peoples for drawing water, for fishing, for sailing." Now the once unlimited resources of marine fishes have become scarce and nations are coming to limit the freedom of their fishers in the commons. From here onward, complete freedom leads to tragedy.

Some History

The concept that air, water, and fish are held in common for use by all was first codified into law by the Romans. In 535 AD, under the direction of Tribonian, the Corpus Iurus Civilis [Body of Civil Law] was issued in three parts, in Latin, at the order of the Emperor Justinian: the Codex Justinianus, the Digest, or Pandects, and the Institutes. The Codex Justinianus (issued in 529 AD) compiled all of the extant (in Justinian's time) imperial constitutions from the time of Hadrian. It used both the Codex Theodosianus and private collections such as the Codex Gregorianus and Codex Hermogenianus. From: The "Codex Justinianus" Medieval Sourcebook: The Institutes, 535 CE. Here is the pertinent text:

Codex Justinianus (529) (Justinian Code), Book II, Part III. The Division of Things:

1. By the law of nature these things are common to mankind---the air, running water, the sea, and consequently the shores of the sea. No one, therefore, is forbidden to approach the seashore, provided that he respects habitationes, monuments, and buildings which are not, like the sea, subject only to the law of nations.

2. All rivers and ports are public; hence the right of fishing in a port, or in rivers, is common to all men.

3. The seashore extends as far as the greatest winter flood runs up. ...

5. The public use of the seashore, too, is part of the law of nations, as is that of the sea itself; and, therefore, any person is at liberty to place on it a cottage, to which he may retreat, or to dry his nets there, and haul them from the sea; for the shores may be said to be the property of no man, but are subject to the same law as the sea itself, and the sand or ground beneath it. ...

12. Wild beasts, birds, fish and all animals, which live either in the sea, the air, or the earth, so soon as they are taken by anyone, immediately become by the law of nations the property of the captor; for natural reason gives to the first occupant that which had no previous owner. And it is immaterial whether a man takes wild beasts or birds upon his own ground, or on that of another. Of course any one who enters the ground of another for the sake of hunting or fowling, may be prohibited by the proprietor, if he perceives his intention of entering.
From: The "Codex Justinianus" Medieval Sourcebook: The Institutes, 535 CE.

A General Statement of the Tragedy of the Commons

The philosopher Herschel Elliott states that there are four general premises that entail the tragedy of the commons:

  1. The Earth is finite: it has a limited stock of renewable fuels, minerals, and biological resources, a limited throughput of energy from the sun, and a finite sink for processing wastes.

  2. Although human activity very often does occur on privately owned lands which are not a commons, that and all other human activities take place in some larger natural commons. And that larger commons is a limited biosystem which is in a dynamic, competitive, and constantly evolving equilibrium. The equilibrium of an ecosystem can usually accommodate any activity on the part of its members as long as that activity is limited in amount and/or is practiced only by a small population. But continuous growth in the numbers of any organism or in its exploitation of land and resources will eventually exceed the capacity of the ecosystem to sustain that organism.

  3. Now for the first time on global scale human beings are exceeding the land and resource use which the Earth's biosystem can sustain.

  4. Certainly it is true, as Hardin noted, that individuals who seek to maximize their material consumption contribute to the ever increasing exploitation of the world's commons. But it is also true that all who follow the rarely questioned principles of humanitarian ethics -- to save all human lives, to relieve all human misery, to prevent and cure disease, to foster universal human rights, and to assure equal justice and equal opportunity for everyone -- do so also.

From A General Statement of Hardin's Tragedy of the Commons by Herschel Elliott.

Some Consequences

The large and rapid increase in population since the beginning of the anthropocene has altered the global commons. Will our atmosphere, rivers, lands, and ocean ultimately be destroyed because they are held in common for use by all? Will we place ever stronger restrictions on their use? Or will we limit the population of the world?

Its message is, I think, still true today. Individualism is cherished because it produces freedom, but the gift is conditional: The more the population exceeds the carrying capacity of the environment, the more freedoms must be given up. As cities grow, the freedom to park is restricted by the number of parking meters or fee-charging garages. Traffic is rigidly controlled. On the global scale, nations are abandoning not only the freedom of the seas, but the freedom of the atmosphere, which acts as a common sink for aerial garbage. Yet to come are many other restrictions as the world's population continues to grow.
– Hardin (1998): Extensions of "The Tragedy of the Commons."

Jared Diamond in his book Collapse describes in detail the collapse of civilizations that failed to solve the problem of the Tragedy of the Commons. He writes of Pitcairn and Henderson Islands in the Pacific (page 120):

Many centuries ago, immigrants came to a fertile land blessed with apparently inexhaustible resources. While the land lacked a few raw materials useful for industry, those materials were readily obtained by overseas trade with poorer lands that happened to have deposits of them. For a time, all the lands prospered, and their populations multiplied.

But the population of that rich land eventually multiplied beyond the numbers that even its abundant resources could support. As its forests were felled and its soils eroded, its agricultural productivity was no longer sufficient to generate export surpluses, build ships, or even to nourish its own population. With that decline of trade, shortages of the imported raw materials developed. Civil war spread, as established political institutions were overthrown by a kaleidoscopically changing succession of local military leaders. The starving populace of the rich land survived by turning to cannibalism. Their former overseas trade partners met an even worse fate: deprived of the imports on which they had depended, they in turn ravaged their own environment until no one was left alive.


Tragedy is not inevitable. Jared Diamond described how some societies avoided tragedy, at least locally. The people of Tikopia, Japan, and the New Guinea highlands saved their forests and the agrarian economy which depended on forests. All limited their population to what could be sustained by their economy.

There Is No Technical Solution
Hardin points out that the Tragedy of the Commons is an example of the class of problems with no technical solution, where:

A technical solution may be defined as 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.
Hardin (1968).

We Must Change Our Values: Mutual Coercion
Therefore, any solution requires that we, as a society, change our values of morality. For example, we may decide that unlimited use of air is no longer morally acceptable. Hardin states one solution is "Mutual Coercion Mutually Agreed Upon." We, as a society, agree that some actions are not allowed (the mutual agreement), and that violations of the agreement leads to fines or prison terms (the Coercion). Thus, we have some restrictions on what can be put into the air. The US Environmental Protection Agency regulates the amount of pollutants that can be released into the air. Failure to comply with the regulations leads to fines or prison sentences.

Hawaiian Islanders protected their environment and fisheries for a thousand years by a unique system of local ownership extending from the sea to the headwaters of streams feeding into the sea. Violations of the rules (taboos) could lead to the death penalty. This was "mutual coercion mutually agreed upon" in the extreme.

death penalty in ancient hawaii
Hawai'ian islanders punishing a guilty person. Lithograph by Langlame: Maniere de punir de mort un coupable aux iles Sandwich. Published in the book by Jacques Etienne Victor Arago, Promenade autour du monde (pendant les annees de 1817, 1818, 1819 et 1820, sur les corvettes du Roi l'Uranie et la Physicienne, commandees par M. Freycinet.
From Grosvenor Prints Hampton, UK.

More General Solutions
In addition, morals or ethics can lead to changes in use of the resource. How can this be done? Ostrom et al (1999) provide a possible answer.

"Solving [commons] problems involves two distinct elements:

  1. Restricting access, and
  2. Creating incentives (usually by assigning individual rights to, or shares of, the resource) for users to invest in the resource instead of overexploiting it.

Both changes are needed. For example, access to the north Pacific halibut fishery was not restricted before the recent introduction of individual transferable quotas and catch limits protected the resource for decades. But the enormous competition to catch a large share of the resource before others did resulted in economic waste, danger to the fishers, and reduced quality of fish to consumers. Limiting access alone can fail if the resource users compete for shares, and the resource can become depleted unless incentives or regulations prevent overexploitation."
From Ostrom et al (1999), "Revisiting the Commons: Local Lessons, Global Challenges."

Restricting access ultimately involves limiting population, especially when the common being accesses is a global system.


Diamond, J. (2005). Collapse: How Societies Choose to fail or Succeed, Viking.

Hardin, Garret. (1969) "The Tragedy of the Commons." Science. 162: 1243-8.

Hardin, G. (1998). "ESSAYS ON SCIENCE AND SOCIETY: Extensions of "The Tragedy of the Commons." Science 280 (5364): 682-683.

Ostrom, E., J. Burger, et al. (1999). Revisiting the Commons: Local Lessons, Global Challenges. Science 284 (5412): 278-282.

A Slovenian translation of this chapter by Gasper Halipovich is available through NextRanks.

Revised on: 15 January, 2013

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