The Tragedy of the CommonsandDistributed

The natural and social sciences have recognized for some time that when rational agents use a shared resource (a \commons") near its capacity, the resource is doomed. This is the tragedy of the commons. The same problem will also arise when agents in a distributed AI system share a resource. In this paper, we examine the tragedy of the commons as it applies to DAI and discuss several potential solutions, including conventions , privatization of the resource, and mutual coercion mutually agreed upon. Solutions to this problem in DAI testbeds will likely also contribute to understanding how to avoid the tragedy of the commons in many areas of current interest to society, such as sheries management, preservation of whale and other species populations, global climate change, and preservation of tropical rainforests. In 1968, biologist Garrett Hardin brought to science's attention a little-known work by the nineteenth century amateur mathematician William Forster Lloyd on population growth and control Hardin, 1968]. Lloyd examined the fate of a common pasture shared among rational, utility-maximizing herdsmen. With increasing population, the pasture is inevitably destroyed. Hardin showed that Lloyd's work has widespread implications not only for population control, but also for the overexploitation and eventual ruin of any resource held in common (a \commons"). This includes both resources that are harvested, such as whales, as well as resources that are used as depositories of waste, such as the air and oceans. Every resource has a carrying capacity e.g., Ricklefs, 1990], the maximum amount of use it can support. Once a resource is being utilized at a rate near its carrying capacity, additional utilization will degrade its value to its current users. Users then will enter into a cycle of additional use of the resource to gain or to try to break even as others use it. Since all users engage in this behavior, the resource is ultimately and inevitably doomed: \Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons" Hardin, 1968]. The inexorable working out of the resource's ruin is Hardin's tragedy of the commons. In human aaairs, the tragedy of the commons has never been more evident than it is today, as we face its eeects of pollution, global warming, ozone depletion, overrshing and extinction of species, and destruction of the rain forests. But what relevance does …