'Prisoner's Dilemma' and the environment

An interesting article in the economist this week on the application of game-theory to evironmental politics. The article likens the current global political environment towards "prisoner's dilemma" a game-theory popularised by Kim Stanley Robinson's protagonist in "sixty days and counting". The dilemma is a study of short-sightedness in small groups and simply put is based on two prisoners under interrogation for the same crime. The 27th September 2007 Economist article titled "playing games with the planet" puts it quite nicely:

The problem, of course, is that if everyone is counting on others to act, no one will, and the consequences could be much worse than if everyone had simply done their bit to begin with. Game theorists call a simplified version of this scenario the “prisoner's dilemma”. In it, two prisoners accused of the same crime find themselves in separate cells, unable to communicate. Their jailers try to persuade them to implicate one another. If neither goes along with the guards, they will both receive a sentence of just one year. If one accepts the deal and the other keeps quiet, then the turncoat goes free while the patsy gets ten years. And if they both denounce one another, they both get five years.

If the first prisoner is planning to keep quiet, then the second has an incentive to denounce him, and so get off scot-free rather than spend a year in prison. If the first prisoner were planning to betray the second, then the second would still be better off pointing the finger, and so receive a five-year sentence instead of a ten-year one. In other words, a rational, self-interested person would always betray his fellow prisoner. Yet that leaves them both mouldering in jail for five years, when they could have cut their sentences to a year if they had both kept quiet.

If you do the simple math, it's pretty obvious that an "always defect" strategy might pay off for you, however in the long run it is a no-brainer to keep silent and be "always generous" and thereby accepting that you will both serve a year. The parallel with climate change is of course that the tendency at the moment is for the tendancy towards "aways defect" and not commit to any meaningful actions. This is particularly obvious with the failure of Australia and the US in ratifying the Kyoto protocol, relying on other nations to do the work without provding in actual captial themselves.

The sad irony of the game-theory is that if the nations worked together they would always be better off in the long-run rather than maneouvering for short-term gains. Greater political forsight and community pressure to see the painfully obvious is clearly needed here, and this can only come through education of the public that 'always defect' doesn't pay off in the long run.