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Abstract - Paradoxes of Game Theoretic Equilibria and Price of Anarchy
For decades, static solution concepts (Nash, Correlated, and Coarse Correlated Equilibria) and the Price of Anarchy (PoA) have formed the bedrock of algorithmic game theory, with no-regret learning proving fast convergence to such game-theoretic equilibria. We show that reducing multi-agent learning to static equilibrium and black-box regret analysis obscures underlying dynamic disequilibrium and game theoretic bounds. First, interior Nash equilibria lack $C^1$ vector field information, meaning agents cannot distinguish aligned from strictly opposing incentives. Inheriting this geometry, the worst-case pure Nash equilibria dictating robust PoA bounds manifest as topologically unstable strict saddles, and in canonical congestion games, as global repellers supported on almost everywhere strictly dominated strategies. Anchoring efficiency guarantees to these unstable states causes algebraic sensitivity; we prove that accommodating all strictly positive affine costs renders the PoA unbounded. Furthermore, projecting learning trajectories onto the discrete simplex of correlated play systematically accommodates non-rationalizable behavior. Evaluating dynamics via Coarse Correlated Equilibria or proximal refinements fails to preclude strictly dominated strategies. Moreover, optimal $O(1/T)$ swap-regret minimization does not preclude macroscopic turbulence, manifesting as chaotic limit sets even in minimal games. Finally, we examine the non-atomic limit of congestion games. Though considered highly stable with tight sub-linear $\Theta(p/\ln p)$ PoA bounds (where $p$ is the polynomial degree), we prove that under discrete-time learning, the unique equilibrium destabilizes into Li-Yorke chaos and global attractors whose time-averaged inefficiency degrades exponentially as $2^p$. These results necessitate re-evaluating worst-case equilibrium frameworks for dynamically grounded metrics.
博弈论均衡与无政府代价中的悖论 /
Paradoxes of Game Theoretic Equilibria and Price of Anarchy
1️⃣ 一句话总结
本文揭示了传统博弈论中静态均衡(如纳什均衡)和无政府代价(PoA)在分析多智能体学习动态时存在的根本缺陷:这些均衡状态可能是拓扑不稳定的排斥点,甚至支持被严格占优策略,导致效率保证极度敏感;即使是最优的遗憾最小化算法也无法避免混沌行为,并且在离散时间学习的拥塞博弈中,唯一均衡会退化为混沌吸引子,使时间平均效率随多项式度数呈指数恶化,从而要求重新审视基于最坏情况均衡的鲁棒性框架。