The political scientist Elinor Ostrom was awarded the Nobel economics prize this week for finding new ways to address an age-old problem: the over-exploitation of “common-pool resources”. If every person in a village has rights to fish out of the same pond, hauls that are reasonable at the personal level may lead in the aggregate to a depletion of stocks and no fish for anyone. So what is one to do?

Those who have considered this problem over the centuries have generally suggested either privatisation or government control. We have had some successes. The air is cleaner than it was 30 years ago. But in general we are bad at thinking about “the commons”. Consider the debate over healthcare in the US. Supporters of healthcare reform warn that Americans consume too much healthcare; a major part of their solution is to offer a “right” to healthcare – i.e. to make the health industry into more of a commonly held resource. Other things being equal, that will lead Americans to consume even more healthcare.