Citation Context

...ic and game theories, for P2P peers to collaborate is crucial to create an economy of equilibrium. When non-cooperative users benefit from free-riding on others’ resources, the tragedy of the commons =-=[98]-=- is inevitable. Such incentives implementation in P2P overlay services would also provide a certain level of self-regulatory auditing and accounting behavior for resource sharing. • Trust and reputati...

Citation Context

...t-tolerance and survivability in the face of node failure. Nodes can enter and leave the collective without administrative action; such systems are entirely decentralized, selforganizing, and scalable [2, 7, 8, 23]. These systems depend on individual nodes consuming storage space in proportion to their contribution. Without such balance, the demand for storage space exceeds supply, and the system collapses. Because the benefit of using the system accrues individually, but the costs are shared, users have little incentive to contribute beyond goodwill. This is called the tragedy of the commons [15]. Recent studies of Gnutella and Napster confirm that many users consume without contributing [1, 24]. Worse, some users under-report their available resources to avoid providing them to others [24]. Several mechanisms to compel storage fairness have been proposed, but all of them rely on one or more features that run counter to the goals of peer-to-peer storage systems. Trusted third parties can enforce quotas and certify the rights to consume storage [23] but require centralized administration and a common domain of control. One can use currency to track the provision and consumption of stor...

Citation Context

... each parasite genotype, when alone in a host, to follow the prudent strategy. There is, however, a problem when two or more genotypes occupy the same host. If one genotype extracts host resources rapidly and reproduces quickly, then the host may die in a short time. A prudent genotype would have relatively low fitness when paired in a host with a rapacious genotype because, for both genotypes, the host is short-lived, and the rapacious genotype reproduces more rapidly than the prudent one. The problem of competing for a shared, limited resource is, colloquially, the "tragedy of the commons" (Hardin 1968, 1993). The shared resource may be used most efficiently by slow, prudent exploitation, but rapacious individuals can gain a disproportionate share of the total by rapid exploitation. Each parasite gains most by balancing the benefit from rapid exploitation and the cost of reducing the total resource (Lewontin 1970; Levin and Pimental 1981). I will analyse the problem of relative gains within the group versus total productivity of the group by using the well known theories of kin selection and group selection (Hamilton 1964a,b, 1975). Closely related parasites are favored to cooperate and exp...