Overlapping coalition formation in game theory: A state-of-the-art review

A coalition as a group of agents aims to work jointly to earn much more gains as a result of their cooperation. Many existing studies assumed that members take advantage of joining one coalition at a time, albeit the importance of coalition formation problems. Therefore, more attention to overlapping coalitions needs to be paid to optimise resource management by forming in multiple overlapping coalitions simultaneously. Roughly speaking, the related literature includes two main streams; (i) theoretical foundations of coalition formation games and, (ii) the coalition structure generation problems. This paper first provides a review of coalition structure generation at large to develop a taxonomic framework and classify the existing literature, viz., macro analysis. The paper then reviews studies on overlapping coalitions thoroughly, viz., micro analysis. The micro analysis presents and discusses different models of overlapping coalition games and related solution concepts as well as surveying all problem-solving approaches for overlapping coalition structure generation. Finally, the outstanding challenges and opportunities for future research considerations are discussed and shared.