Volunteer's dilemma

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The volunteer's dilemma game models a situation in which each player can either make a small sacrifice that benefits everybody, or instead wait in hope of benefiting from someone else's sacrifice.

Game theory is the study of mathematical models of strategic interaction among rational decision-makers. It has applications in all fields of social science, as well as in logic, systems science, and computer science. Originally, it addressed zero-sum games, in which each participant's gains or losses are exactly balanced by those of the other participants. Today, game theory applies to a wide range of behavioral relations, and is now an umbrella term for the science of logical decision making in humans, animals, and computers.


One example is a scenario in which the electricity supply has failed for an entire neighborhood. All inhabitants know that the electricity company will fix the problem as long as at least one person calls to notify them, at some cost. If no one volunteers, the worst possible outcome is obtained for all participants. If any one person elects to volunteer, the rest benefit by not doing so. [1]

A public good is only produced if at least one person volunteers to pay an arbitrary cost. In this game, bystanders decide independently on whether to sacrifice themselves for the benefit of the group. Because the volunteer receives no benefit, there is a greater incentive for freeriding than to sacrifice oneself for the group. If no one volunteers, everyone loses. The social phenomena of the bystander effect and diffusion of responsibility heavily relate to the volunteer's dilemma.[ citation needed ]

Public good (economics) Good that is non-excludable and non-rival

In economics, a public good is a good that is both non-excludable and non-rivalrous in that individuals cannot be excluded from use or could be enjoyed without paying for it, and where use by one individual does not reduce availability to others or the goods can be effectively consumed simultaneously by more than one person. This is in contrast to a common good such as wild fish stocks in the ocean, which is non-excludable but is rivalrous to a certain degree, as if too many fish are harvested, the stocks will be depleted.

The bystander effect, or bystander apathy, is a social psychological claim that individuals are less likely to offer help to a victim when other people are present; the greater the number of bystanders, the less likely it is that one of them will help.

Diffusion of responsibility is a sociopsychological phenomenon whereby a person is less likely to take responsibility for action or inaction when others are present. Considered a form of attribution, the individual assumes that others either are responsible for taking action or have already done so.

Payoff matrix

The payoff matrix for the game is shown below:

Volunteer's dilemma payoff matrix (example)
at least one other person cooperatesall others defect

When the volunteer's dilemma takes place between only two players, the game gets the character of the game 'chicken'. As seen by the payoff matrix, there is no dominant strategy in the volunteer's dilemma. In a mixed-strategy Nash equilibrium, an increase in N players will decrease the likelihood that at least one person volunteers, which is a result of the bystander effect.

The game of chicken, also known as the hawk–dove game or snowdrift game, is a model of conflict for two players in game theory. The principle of the game is that while it is to both players’ benefit if one player yields, the other player's optimal choice depends on what their opponent is doing: if the player opponent yields, they should not, but if the opponent fails to yield, the player should.

In game theory, the Nash equilibrium, named after the mathematician John Forbes Nash Jr., is a proposed solution of a non-cooperative game involving two or more players in which each player is assumed to know the equilibrium strategies of the other players, and no player has anything to gain by changing only their own strategy.

Examples in real life

The murder of Kitty Genovese

The story of Kitty Genovese is often cited as an example of the volunteer's dilemma. Genovese was stabbed to death outside her apartment building in Queens, New York, in 1964. According to a highly influential New York Times account, dozens of people witnessed the assault but did not get involved because they thought others would contact the police anyway and did not want to incur the personal cost of getting involved. [2] Subsequent investigations have shown the original account to have been unfounded, and although it inspired sound scientific research, its use as a simplistic parable in psychology textbooks has been criticized. [3]

The meerkat

The meerkat exhibits the volunteer's dilemma in nature. One or more meerkats act as sentries while the others forage for food. If a predator approaches, the sentry meerkat lets out a warning call so the others can burrow to safety. However, the altruism of this meerkat puts it at risk of being discovered by the predator.

Meerkat species of small carnivoran in the mongoose family (Herpestidae)

The meerkat or suricate is a small carnivoran in the mongoose family. It is the only member of the genus Suricata. Meerkats live in all parts of the Kalahari Desert in Botswana, in much of the Namib Desert in Namibia and southwestern Angola, and in South Africa. A group of meerkats is called a "mob", "gang" or "clan". A meerkat clan often contains about 20 meerkats, but some super-families have 50 or more members. In captivity, meerkats have an average life span of 12–14 years, and about 6–7 years in the wild.

See also

Related Research Articles

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In the early hours of March 13, 1964, 28-year-old Kitty Genovese was stabbed outside the apartment building across the street from where she lived in an apartment above a row of shops on Austin street in Kew Gardens, Queens, a borough of New York City. Two weeks after the murder, The New York Times published an article claiming that 38 witnesses saw or heard the attack, but none of them called the police or came to her aid.

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  1. Poundstone, William (1993). Prisoner's Dilemma: John von Neumann, Game Theory, and the Puzzle of the Bomb. New York: Anchor Books. ISBN   978-0-385-41580-4.
  2. Weesie, Jeroen (1993). "Asymmetry and Timing in the Volunteer's Dilemma". Journal of Conflict Resolution . 37 (3): 569–590. doi:10.1177/0022002793037003008. JSTOR   174269.
  3. Manning, R.; Levine, M; Collins, A. (September 2007). "The Kitty Genovese murder and the social psychology of helping: The parable of the 38 witnesses". American Psychologist . 62 (6): 555–562. CiteSeerX . doi:10.1037/0003-066X.62.6.555. PMID   17874896.