A behavioral definition of unforeseen contingencies

Abstract The paper proposes a choice-theoretic definition of an unforeseen event and a model of behavior that accommodates such events. The analysis presumes an individual who is aware of their unawareness, which explains why all unforeseen events in this paper are non-null. Relative to existing work, the main contribution is to establish a distinction between unforeseen events and events whose likelihood is ambiguous. This is achieved by adopting a dynamic choice setting.