Unawareness and Zero Probability

I study how choice behavior given unawareness of an event differs from choice behavior given subjective belief of zero probability on the event in an axiomatic framework. Depending on different types of unawareness the decision maker suffers, behavior is either incomparable with zero probability (in the case of pure unawareness), or allows for drastically different behavior than those under zero probability (in the case of partial unawareness). The key difference is that partial unawareness is consistent with dynamically inconsistent choice which is not possible under zero probability beliefs.

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