Yours, mine, ours--or nobody's?

• Author: Gardner, Gary
• Position: GROUNDWORK - Conservation of public resources

My two young children are wrestling with one of life's more difficult concepts: sharing. They are particularly challenged when it comes to sharing things that are owned by nobody in particular, like a favorite seat in the car, our set of children's books, or "air time"--who gets Mom's or Dad's attention at any given moment. Unlike their clothes and toys, these common resources are up for grabs, and they generate arguments almost hourly. What's more, taking care of our shared assets seems to be nobody's job. "Who could possibly have left these books all over the floor?" my wife and I bellow. Little arms point toward each other like drawn swords.

Sam and Clara's skirmishes are our version of a vexing challenge for sustainability: how to manage--share, really--resources that are freely available to all, such as the airwaves or the skies that absorb our factory and vehicle exhausts. These are "the commons"--valuable resources which have no gatekeeper to restrict access, and which can be used up. (These differ from commonly owned properties, such as national parks, which also, unhelpfully, often bear the label "commons" or "common resources." In this column, commons refers only to those freely available, but limited, natural resources that are not yet managed or regulated.)

Freely available resources were first written about by Aristotle, who observed that things accessible to all are given the least care. Garrett Hardin made the problem famous in his 1968 essay "The Tragedy of the Commons," noting that open-access issues pose particular challenges in an increasingly crowded world because of the mismatch between private incentives to use the resources and the societal interest in protecting them. Hardin's formula: Limited Resource + No Gatekeeper = Tragedy.

Hardin cited the case of the village pasture, a resource available to all villagers for grazing their livestock. The farmer who grazes his sheep on the commons gets a fatter animal, which is exclusively his, while erosion of the pasture is a problem spread across the entire village. All the other villagers, of course, recognize the same lopsided payoff, and want a piece of the action. Soon the commons is overrun and the pasture is worn raw. The lesson of an unregulated commons, says Hardin, is that pursuing one's own interest leads inexorably to a "tragedy" for all, in which everyone is left worse off than if the commons had somehow been managed. And what is true for the village is true...