Intuitively, we expect that players who are allowed to engage in costless communication before playing a game would be foolish to agree on an inefficient equilibrium. At the same time, however, such preplay communication has been suggested as a rationale for expecting Nash equilibrium in...

Games with multiple Nash equilibria are believed to be easier to play if players can communicate. We present a simple model of communication in games and investigate the importance of when communication takes place. Sending a message before play captures talk about intentions, after play...