commons in a community where everyone knows everyone else can be protected by a multiplayer version of Tit for Tat: any exploiter of a resource becomes a target of gossip, shaming, veiled threats, and discreet vandalism.21 In larger and more anonymous communities, changes to the payoffs must be made by enforceable contracts and regulations. And so we pay taxes for roads, schools, and a court system, with evaders sent to jail. Ranchers buy grazing permits, and fishers respect limits on their catch, as long as they know they’re being enforced on the other guy, too.
