Refinements and Higher Order Beliefs : A Unified Survey

This paper presents a simple framework that allows us to survey and relate some different strands of the game theory literature. We describe a "canonical" way of adding incomplete information to a complete information game. This framework allows us to give a simple "complete theory" interpretation (Kreps 1990) of standard normal form refinements such as perfection, and to relate refinements both to the "higher order beliefs literature" (Rubinstein 1989; Monderer and Samet 1989; Morris, Rob and Shin 1995; Kajii and Morris 1997a) and the "payoff uncertainty approach" (Fudenberg, Kreps and Levine 1988; Dekel and Fudenberg 1990)