The "tragedy of the commons"

analyzed by Jared Diamond in relation to Montana.

The Case | opposing evidence| the exceptions | conflicts | solutions? | summary | links | dirty dozen

SheepSheep grazing in a pasture so closely crop the grass that it requires a recovery period to keep the sod productive.

"One particular form of clashes of interest has become well known under the name 'tragedy of the commons,' in turn closely related to the conflicts termed 'the prisoner's dilemma,' and 'the logic of collective action.' Consider a situation in which many consumers are harvesting a communally owned resource [a water well], such as a fisherman catching fish in an area of the ocean, or herders grazing their sheep on a common pasture."

"If everybody overharvests the resource, it will become depleted. . . and thus decline or disappear, and all of the consumers will suffer."

"It therefore would be in the common interest of all consumers to exercise restraint and not overharvest. But as long as there is no effective regulation of how much resource each consumer can harvest, then each consumer would be correct to reason, 'If I don't catch that fish or let my sheep graze that grass, some other fisherman or herder will anyway, so it makes no clear sense for me to refrain from the overfishing or overharvesting.' The correct rational behavior is then to harvest before the next consumer can, even though the eventual result may be the destruction of the commons and thus harm for all consumers."

shad fish

Shad: a fishery that has been depleted in coastal waters from overfishing, pollution, and d

"In reality ...others [commonly used resources] have been preserved in the face of harvesting hundreds even thousands of years. Unhappy outcomes include the overexploitation and collapse of most major marine fisheries, and the extermination of much of the megafauna (big animals) on every oceanic island [New Zealand: the Moa bird] settled by humans for the first time within the last 50,000 years."

"Behind these happy outcomes lie three alternative arrangement that have evolved to preserve a common resource while still permitting a sustainable harvest."

pp. 428-429.

Ways to maintain a commonly used source
options kind of step for example
enforce quotas Tukogawa shogunate, Inca water-use, German lords
privatize the resource "divide it into individually owned tracts."
recognition of similar interests design, obey and enforce

p. 429.

Western Forest

National Forests are federally protected so there is adequate water for settlement in the far west.

"A good example is the case of Montana water rights for irrigation. While the allocation of those rights has been written into law, nowadays the ranchers mostly obey the water commissioner whom they themselves elect, and they no longer take their disputes to court for resolution."

p. 429.

"Other such examples of homogenous groups prudently managing resources that they expect to pass on to their children are the Tikopia Islanders. New Guinea highlanders, members of Indian castes, and ...Icelanders and the Tukogawa Japanese constituting large groups, were further motivated to reach agreement by their effective isolation: it was obvious to the whole group that they would have to survive just on their resources for the foreseeable future.

pp. 429-430.

Conflicts that are irreconcilable:

"Clashes of interest involving rational behavior are also prone to arise when the principle consumer has no long-term stake in preserving the resource but society as a whole does."

p. 430.

"All of these examples ...illustrate situations in which society fails to try to solve perceived problems because the maintenance of the problem is good for some people."

p. 432.

unreasonable motivations

"irrational behavior"

"behavior that is harmful to everybody."

"and 'mental standstill, or stagnation' are among the phrases that Barbara Tuchman applies to this common human trait. Psychologists us the term 'sunk-cost effect' for a related trait: we feel reluctant to abandon a policy (or sell a stock) in which we have already invested heavily."

for related concepts see: cultural sclerosis | bias | dogma | perception

Icelandic norsemen:

"their tightly communal and mutually supportive society allowed them to survive for centuries. But those admirable (and, for a long time, successful) traits also prevented them from making drastic life-style changes and selective adoptions of Inuit [Eskimo native groups indigenous to Arctic biome] technology that night have helped them survive longer."

"In modern times, the reasons why Montanans have been so reluctant to solve their problems caused by mining, logging, and ranching is that those industries used to be the pillars of the Montana economy, and that they have been bound up with Montana's pioneer spirit and identity."

"...made them reluctant to accept their new need for government planning and for curbing individual rights."

p. 432.


"It is painfully difficult to decide whether to abandon some of one's core values when they seem to be becoming incompatible with survival."

"Perhaps a crux of success or failure as a society is to know which core values to hold on to, and which ones to discard and replace with new values, when times change."

p. 433.

"The final speculative reason that I shall mention for irrational failure to try to solve a perceived problem is psychological denial. This is a technical term with with a precisely defined meaning in individual psychology, and it has been taken over into pop culture. If something you perceive arouses in you a painful emotion, you may subconsciously suppress or deny your perception in order to avoid the unbearable pain, even though the practical results of ignoring your perception may prove ultimately disastrous."

p. 435.

Some examples of outworn beliefs, values, or behavioral justifications:

      1. independent imperialism (Britain and France)
      2. militarism (Japan)
      3. communism (Russia)
      4. legal racial discrimination (US)
      5. legalized homophobia (US)
      6. subordination of women (US)
      7. sexual repression (US)
      8. Apartheid (Union of So uh Africa)
      9. divorce & contraception (Episcopalians)
      10. homosexuality as mental illness (The American Psychological Association)
      11. mixed marriages between religions (Catholicism)
      12. legally enforced chattel slavery (Europe and America)

p. 433.


His suggested solutions.

Jared Diamond, Collapse: How Societies choose to fail or succeed. London: Penguin Books, 2005.

Garrett Hardin, Analysis of the original essay.

American exceptionality.

America's conflicting values.

dialectical analysis


What is a commons?


cultural hearths | social drag & cultural lag | deifying progress | commons as a bad game