Deriving consensus in multiagent systems

Consider the designers of a multiagent environment, who are charged with establishing the rules by which agents in an encounter will interact. Once the rules of encounter have been determined, each builder of each agent is free to design his own machine any way that he wants. However, the rules that were established will certainly affect the choices he makes in building his own agent. In this article we suggest an economic decision process that can be used to derive multiagent consensus, namely, the Clarke tax mechanism (E.H. Clarke, 1971). Consensus is reached through the process of voting; each agent expresses its preferences, and a group choice mechanism is used to select the result. Clarke tax-like mechanisms provide a set of attractive alternatives for the designers of multiagent environments, particularly if those environments consist of individually motivated heterogeneous agents. The Clarke tax mechanism has many desirable properties such as non-manipulability, individual rationality, and maximization of the agents' global utility. However, though theoretically attractive, the Clarke tax presents a number of difficulties when one attempts to use it in practical implementations. This article examines how the Clarke tax could be used as an effective consensus mechanism in domains consisting of automated agents. In particular, we consider how agents can come to a consensus without needing to reveal full information about their preferences, and without needing to generate alternatives prior to the voting process.