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...

This paper investigates a general relationship between risk and time preferences. I consider a decision maker who chooses between consumption of a particular prize in one period and a different prize in another period. The individual believes that today’s good is certain, and that, as the...