Reputation in the Venture Games

In many environments, interdependent agents must work cooperatively to be successful. Cooperative ventures require the participation of multiple partners, and successful ventures require that all partners in the venture fulfill their obligations. In such environments, an agent must identify potential partners with the ability and willingness to help it reach its goals while avoiding potential partners who lack the skill or the motivation to help the agent succeed. This paper addresses the problem of how agents in an uncertain world may gain knowledge about the competence of potential partners under a variety of circumstances and use that knowledge to their benefit. As used in this study, competence is a measure of whether an agent has the skills and resources to complete a venture successfully.1 Different potential partners have different levels of competence, so any knowledge regarding the competence of particular individuals provides a competitive edge in deciding whether to deal with those individuals. Reputation—a community-based assessment of agent competence—can augment direct experience, but is prone to error. A large series of experiments was conducted to study systematically the extent to which the usefulness of reputation information varies by group size, group competence, use of reputation, and error in the reputation information. Results confirm that the relative usefulness of direct experience and reputation depends on the particular multi-agent setting and that the utility received from reputation increases as group size increases. The study also yielded two surprising results: first, a pigeonholing phenomenon2 in which reputation wrongly identifies some agents as having sub-par competence based on early random sequences of poor performance, even when agents are generally highly capable. This effect can be countered by introducing systematic positive bias to the reputation system. Second, reputation is useful even in small groups, but only before agents have had much opportunity to interact.