Information paths and learning in games: Experimental evidence

Information in repeated real-world interactions is rarely fixed. Instead, over time, players typically learn more about the game structure, understand more about their own payoff correspondences, and find out what others did and earned in the past. However, how this dynamic information path influences learning and which aggregate outcomes are reached as a result have not been investigated to date. To study this, we conducted a series of laboratory experimental games where we provided more information over time in different orders and along different paths. These games span two strategically distinct classes: a Cournot game with a unique symmetric Nash equilibrium, and step-level public-goods (coordination) games with multiple Nash equilibria of differing Pareto efficiency. Our evidence confirms a natural mapping from information to predominant learning rule: information about own payoffs triggers payoff-based learning, feedback concerning others’ realized payoffs triggers imitation, and structural information about the game triggers best response. In addition, when multiple learning rules are feasible, which one dominates depends on information paths. In particular, feedback about others’ actions and payoffs, especially when supplied marginally, may trigger persistent imitation that locks into Pareto-inferior Nash equilibria, even when more information later becomes available.