Surowiecki on the lessons of behavioural economics:
Behavioral economists have shown that a sizable percentage of people are willing to pay real money to punish people who are taking from a common pot but not contributing to it. Just to insure that shirkers get what they deserve, we are prepared to make ourselves poorer. Similarly, a famous experiment known as the ultimatum game—one person offers another a cut of a sum of money and the second person decides whether or not to accept—shows that people will walk away from free money if they feel that an offer is unfair. Thus, even when there’s a solution that would leave everyone better off, a fixation on fairness can make agreement impossible.