I study how choice behavior given unawareness of an event differs from choice behavior given subjective belief of zero probability on that event. Depending on different types of unawareness the decision-maker suffers, behavior under unawareness is either incomparable with that under zero...

I construct a state space model with unawareness following Aumann (1976). Dekel, Lipman and Rustichini (1998a) show that standard state space models are incapable of representing unawareness. The model circumvents the impossibility result by endowing the agent with a subjective state space that...

This paper extends Li (2008b) to the multi-agent environment, where players reason about each other's awareness as well as knowledge, subject to their own awareness constraints. I characterize the interactive knowledge hierarchies under unawareness, which significantly differ from those in the...

I develop a set-theoretic model of unawareness without making any structural assumptions on the underlying state space. Unawareness is characterized as a measurability constraint that results in players' reasoning about a "coarse" subjective algebra of events. The model is shown to be...