Information and Beliefs in Game Theory

Game theory is devoted to the study of strategic interactions between several rational players. It is concerned by information since players have some uncertainty about their environment and compensate for it by direct observation or by transmission from other players. It is concerned by beliefs since players form expectations about their environment by relying on representations about it as well as representations about others’ representations. Information and beliefs are strongly linked since acquired information modifies the prior beliefs and uncertain beliefs ask for more information. Hence, information and beliefs became together a central topic of game theory and even appear as the main tool allowing the players to coordinate. Moreover, since game theory grounds economic theory, their study leads directly to the ‘economics of information’ (Macho-Stadler et alii, 2001) and to the ‘economics of knowledge’ (Foray, 2004).