Tag: cooperation

The Tragedy of the Commons

In December 1968 Science magazine published a paper by Garrett Hardin entitled “The Tragedy of the Commons”… [it] became one of the most cited academic papers ever published and its title a catch phrase. It has framed the debate about common property for the last 30 years…

Hardin’s basic argument was that common property systems allow individuals to benefit at a cost to the community, and therefore are inherently prone to decay, ecological exhaustion and collapse. Hardin got the idea for his theory from the Oxford economist, the Rev William Forster Lloyd…

– From A short history of enclosure in Britain by Simon Fairley.

Why are the cattle on a common so puny and stunted? Why is the common itself so bareworn and cropped so differently from the adjoining enclosures? If a person puts more cattle into his own field, the amount of the subsistence which they consume is all deducted from that which was at the command of his original stock; and if, before, there was no more than a sufficiency of pasture, he reaps no benefit from the additional cattle, what is gained one way, being lost in another. But if he puts more cattle on a common, the food which they consume forms a deduction which is shared between all the cattle, as well that of others as his own, and only a small part of it is taken from his own cattle.

– Rev William Forster Lloyd, 1833, quoted in A short history of enclosure in Britain by Simon Fairley.

The rational herdsman concludes that the only sensible course for him to pursue is to add another animal to his herd. And another; and another . . . But this is the conclusion reached by each and every rational herdsman sharing a commons. Therein is the tragedy. Each man is locked into a system that compels him to increase his herd without limit — in a world that is limited. Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons. Freedom in a commons brings ruin to all.

An alternative to the commons need not be perfectly just to be preferable. With real estate and other material goods, the alternative we have chosen is the institution of private property coupled with legal inheritance. Is this system perfectly just? . . . We must admit that our legal system of private property plus inheritance is unjust — but we put up with it because we are not convinced, at the moment, that anyone has invented a better system. The alternative of the commons is too horrifying to contemplate. Injustice is preferable to total ruin.

– From ‘The Tragedy of the Commons’ by Garrett Hardin, ‘Science’, 1968, quoted in A short history of enclosure in Britain by Simon Fairley.

Thirty years have passed since Garrett Hardin’s influential article “The Tragedy of the Commons”. At first, many people agreed with Hardin’s metaphor that the users of a commons are caught in an inevitable process that leads to the destruction of the very resource on which they depend. The “rational” user of a commons, Hardin argued, makes demands on a resource until the expected benefits of his or her actions equal the expected costs. Because each user ignores costs imposed on others, individual decisions cumulate to a tragic overuse and the potential destruction of an open-access commons. Hardin’s proposed solution was “either socialism or the privatism of free enterprise”.

Although tragedies have undoubtedly occurred, it is also obvious that for thousands of years people have self-organized to manage common-pool resources, and users often do devise long-term, sustainable institutions for governing these resources. The prediction that resource users are led inevitably to destroy CPRs is based on a model that assumes all individuals are selfish, norm-free, and maximizers of short-run results. This model explains why market institutions facilitate an efficient allocation of private goods and services, and it is strongly supported by empirical data from open, competitive markets in industrial societies. However, predictions based on this model are not supported in field research or in laboratory experiments in which individuals face a public good or CPR problem and are able to communicate, sanction one another, or make new rules. Humans adopt a narrow, self-interested perspective in many settings, but can also use reciprocity to overcome social dilemmas.

– From ‘Revisiting the Commons: Local Lessons, Global Challenges’ by Elinor Ostrom, Joanna Burger, Christopher B. Field, Richard B. Norgaard, and David Policansky, ‘Science’, 1999. The lead author of this article, Elinor Ostrom, was awarded the Nobel Prize in economics in 2009.


The Parable of Tit for Tat

Tit for tat is an English saying meaning “equivalent retaliation”. It is also a highly effective strategy in game theory for the iterated prisoner’s dilemma. The strategy was first introduced by Anatol Rapoport in Robert Axelrod’s two tournaments, held around 1980. Notably, it was (on both occasions) both the simplest strategy and the most successful.

Wikipedia: Tit for tat

An except from No-one makes you shop at Wal-Mart by Tom Slee p 80-82, slightly paraphrased:

The winner was to be the strategy that accumulated the most points over the tournament. The conditions for victory did not include “beating” opponents in individual games, all that mattered was the number of points scored overall. Sophistication was not the key to success: the winner was the simplest strategy, the now well-known Tit-for-Tat:

  • On the first move, co-operate.
  • On every subsequent move, play what the other player played on the previous move.

Tit-for-Tat exemplifies reciprocity. It successfully encourages, using a mixture of carrot and stick, other strategies to take part in mutually beneficial co-operation. Overall it got the most points of any strategy even though, or perhaps even because, it can never do better than any “opponent”. Instead, its success at encouraging co-operation means that games in which it plays are high-scoring.

There is no unambiguous “best strategy” for the game. Nevertheless considerable empirical evidence supports the observation that under a wide range of conditions, Tit-for-Tat and similar strategies are highly successful. Most of these successful strategies shared traits which Axelrod highlighted in his analysis:

BE NICE. Co-operating on the first move makes it possible for a mutually beneficial pattern of co-operation to be established.

BE UNEXPLOITABLE. By responding to defection with defection, Tit-for-Tat avoids being exploited by strategies designed to take advantage of overly generous opponents.

BE FORGIVING. If the opponent co-operates just once, Tit-for-Tat will forget about all previous defections. This prevents mutually destructive cycles of revenge from being established.

BE CLEAR. It’s easy to see what Tit-for-Tat is doing, making it easy for other strategies to settle into patterns of mutually beneficial co-operation.

The Parable of Tit for Tat

How to be kind, without letting others abuse your kindness? How to act with compassion and openness, when the world seems to punish these things? How to build a life of bountiful co-operation instead of endlessly competing in zero-sum games?

The parable of Tit for Tat suggests a way: be optimistic and friendly by default, but punish immediately those who harm you. Let others see clearly how you protect and care for your allies, and let them see clearly what they have to do in order to become your ally.

Let them see that you are as immovable as the bedrock. You are playing the strategy that seems best to you, and you will not be swayed from it. They cannot convince you or cajole you. They cannot change your behaviour, they can only change their own.

Is Tit for Tat morally good? Is the wrong question. It’s just a good strategy, a technique that can be used for good or for ill. But it’s interesting to note that Tit for Tat is exactly the way you should treat a child who sometimes misbehaves, or an adult who is hurting too much to fully take care of themself. Which is to say: most adults, if we’re honest.