A Primer on Opportunism Viewed from the Perspective of Multi-Agent Systems

Opportunistic behavior is a selfish behavior that takes advantage of knowledge asymmetry and results in promoting agents’ own value but demoting other agents’ value. It commonly exists in business transactions and social interactions, thereby gaining much attention and investigation from social science. In the context of multi-agent systems, it is normal that knowledge is distributed among different agents, which creates the opportunity for agents to perform opportunistic behavior to other agents. Since opportunistic behavior has undesirable results for other agents in the system, the aim of this book is to eliminate such a selfish behavior from the system. We first propose a formal account of opportunism based on the situation calculus to have a thorough understanding of opportunism. Because opportunistic behavior has undesirable results for other agents in the system but cannot be observed indirectly, there has to be a monitoring mechanism that can detect the performance of opportunistic behavior. We secondly provide a logical framework to specify monitoring approaches for opportunism. In order for monitoring and eliminating mechanisms to be put in place, it is important to know in which context agents will or are likely to perform opportunistic behavior. Therefore, we develop a framework to reason about agents’ opportunistic propensity. Finally, we reach our goal through designing two mechanisms for eliminating opportunism.