We analyze a mechanism that provides strong incentives for the submission of truthful feedback in virtual communities where
services are exchanged on a peer-to-peer basis. Lying peers are punished with a severity that is exponential to their frequency
of lying. We had first introduced and evaluated experimentally the mechanism in [1]. In this paper, we develop a Markov-chain
model of the mechanism. Based on this, we prove that, when the mechanism is employed, the system evolves to a beneficial steady-state
operation even in the case of a dynamically renewed population. Furthermore, we develop a procedure for the efficient selection
of the parameters of the mechanism for any peer-to-peer system; this procedure is based on ergodic arguments. Simulation experiments
reveal that the procedure is indeed accurate, as well as effective regarding the incentives provided to participants for submitting
truthful feedback.
The present work was partly funded by the IST project EuroNGI (IST-2003-507613).