Players can secretly coordinate actions in repeated games, changing outcomes.
The article shows that in repeated games where players receive signals after each round, if the signals sometimes reveal information, then the Nash equilibrium payoffs are the same as the correlated equilibrium payoffs. This means that players can internally coordinate their actions without an outside mediator. The researchers demonstrate how players can create any correlation device using the game's signaling structure. This finding suggests that strategies that work in a single round of the game can also be successful in repeated rounds.