Approximating the Core via Iterative Coalition Sampling
<|reference_start|>Approximating the Core via Iterative Coalition Sampling: The core is a central solution concept in cooperative game theory, defined as the set of feasible allocations or payments such that no subset of agents has incentive to break away and form their own subgroup or coalition. However, it has long been known that the core (and approximations, such as the least-core) are hard to compute. This limits our ability to analyze cooperative games in general, and to fully embrace cooperative game theory contributions in domains such as explainable AI (XAI), where the core can complement the Shapley values to identify influential features or instances supporting predictions by black-box models. We propose novel iterative algorithms for computing variants of the core, which avoid the computational bottleneck of many other approaches; namely solving large linear programs. As such, they scale better to very large problems as we demonstrate across different classes of cooperative games, including weighted voting games, induced subgraph games, and marginal contribution networks. We also explore our algorithms in the context of XAI, providing further evidence of the power of the core for such applications.<|reference_end|>
@article{gemp2024approximating,
    title={Approximating the Core via Iterative Coalition Sampling},
    author={Ian Gemp, Marc Lanctot, Luke Marris, Yiran Mao, Edgar
  Du'e~nez-Guzm'an, Sarah Perrin, Andras Gyorgy, Romuald Elie, Georgios
  Piliouras, Michael Kaisers, Daniel Hennes, Kalesha Bullard, Kate Larson,
  Yoram Bachrach},
    journal={arXiv preprint arXiv:2402.03928},
    year={2024},
    archivePrefix={arXiv},
    eprint={2402.03928},
    primaryClass={cs.GT cs.MA}
}