Overcoming Free-Riding in Bandit Games
研究一类包含Lévy强盗的实验博弈，发现当玩家收益存在扩散成分时，存在有效（完美贝叶斯）均衡，表明文献中强调的权衡并非源于强盗模型的本质，而是源于常用的马尔可夫完美均衡概念。
Abstract This article considers a class of experimentation games with Lévy bandits encompassing those of Bolton and Harris (1999, Econometrica, 67, 349–374) and Keller, Rady, and Cripps (2005, Econometrica, 73, 39–68). Its main result is that efficient (perfect Bayesian) equilibria exist whenever players’ payoffs have a diffusion component. Hence, the trade-offs emphasized in the literature do not rely on the intrinsic nature of bandit models but on the commonly adopted solution concept (Markov perfect equilibrium). This is not an artefact of continuous time: we prove that efficient equilibria arise as limits of equilibria in the discrete-time game. Furthermore, it suffices to relax the solution concept to strongly symmetric equilibrium.