Raiffa (1961) criticizes ambiguity-averse preferences by claiming that hedging is possible with randomization of choices. We argue that the timing of randomization is crucial for hedging. Ex-ante randomizations, which are randomizations before a state is realized, could provide only ex-ante...

Individuals exhibit a randomization preference if they prefer random mixtures of two bets to each of the involved bets. Such preferences provide the foundation of various models of uncertainty aversion. However, it has to our knowledge not been empirically investigated whether uncertainty-averse...

We propose and axiomatically characterize a representation of ambiguity sensitive preferences. The distinguishing feature of our axiomatization is that we do not require preferences to be event-wise separable over any domain of acts. Even without any such separability restrictions, we are able...