Vulnerability of Reputation Management System due to Tolerant Evaluation

Proc. of the 4th Conference of the European Social Simulation Association,pp.585-596,2007(9)

Yamamoto, Hitoshi, Isamu Okada and Toshizumi Ohta


Reputation management system is effective for promotion of cooperative behaviors in online transaction. However, it may be hard for a trader to evaluate his/her partner accurately on the transaction because of his/her fear for the retaliatory evaluation or of the expectation to positive evaluation from his/her partner. Traders have not only the strategy for behaviors but also that for evaluations. In order to analyze the influences of inaccurate evaluation in the reputation management system, we model an online consumer-to-consumer market. The results show that the dominant strategy among traders for evaluation is cooperative while that for behavior is non-cooperative. The domination of non-cooperative behaviors is derived from that the tolerant evaluation cannot eliminate those behaviors. We conclude that reciprocal evaluations by unmalicious participants cause an inflation of reputation and may prevent the reputation management system from functioning properly.


go Hitoshi Yamamoto Study work || go Hitoshi Yamamoto top || UEC Social Infomation Systems Laboratory || University of Electro-Communications