The Standing Invitation

Archive for August 25th, 2011

A Common Tragedy

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The Tragedy of the Commons occurs when a number of people using a finite resource realise that they each stand to gain from taking more than their fair share. You know everybody else benefits from taking more, so that’s probably what they are doing; the more likely they are to be taking more, the more sense it makes for you to take more. And since everybody knows that it makes sense for you to take more… and so on, until the resource is depleted.

Fishers often know that their overfishing will lead to extinction of certain species of fish, and farmers often know that overfarming will leave the land infertile; but cessation is simply not feasible for them as individuals competition.

In a way the problem of short-term benefits outweighing long-term disadvantages resembles addiction. An chocoholic knows chocolate will make him fat; but it’s just too tasty to say no to! His willpower isn’t strong enough.

But our chocoholic friend has an option: he can employ a willpower-assisting strategy. He might not feel he needs chocolate just now, but can imagine a future point when the craving really sets in, when his willpower won’t be enough. So he acts now, while he can, and flushes the chocolate down the toilet, removing the temptation in advance. He enacts policy that anticipates future temptations. Sometimes people entrust this to others. “Don’t bring me any chocolate, I’ll only end up eating it.”

This is one solution to the Tragedy of the Commons. The consumers make a pact: they all agree to how much they can safely extract from the resource, and agree to be punished if they take more, even if ­– especially if ­– it later becomes profitable in the short term to do so. This leads to the creation of national parks, protected areas, one-child policies, fishing quotas and so on.

This kind of contract exploits a very human difference in our valuation of rewards depending on how far away in the future they are. Agreeing to protect a resource is easy when the resource is plentiful.

The trouble is that a sufficiently plentiful resource might not even be seen as a resource. What value do you place, for example, on air? Not much, until you start to see it polluted.

There was a time when the Earth was seen by most people as an infinite source and an infinite sink. Why regulate things that will never run out? It is only after we realise that something is in danger that it makes sense to protect it ­– but if the realisation comes late, and we see that the resource is actually scarce, then the short-term benefits of looting it faster than the other fella become very real to us indeed.

There is a time window between thinking something too free to regulate and thinking it too precious to regulate, and the window is often narrow. What have we missed it for? And what do we still have time to protect from our future, greedier selves?


This was written on a train having just finished The Logic of Life by Tim Harford, and with Dennett’s Freedom Evolves fresh in memory. Both very worth reading.


Written by The S I

August 25, 2011 at 11:59 pm