For choice with deterministic consequences, the standard rationality hypothesis is ordinality, i.e., maximization of a weak preference ordering. For choice under risk (resp. uncertainty), preferences are assumed to be represented by the objectively (resp. subjectively) expected value of a von...

Two distinct interpretations of ambiguity attitudes have been proposed, namely, weighting the multiple priors pessimistically and exhibiting preference over different sources of uncertainty. This study examines the links among attitudes towards three sources of uncertainty including ambiguity...

Keynes (1921) and Ellsberg (1961) have articulated an aversion toward betting on an urn containing balls of two colors of unknown proportion to one with a 50-50 composition. Keynes views this as reflecting different preferences for bets arising from different sources of uncertainty. Ellsberg...

This paper analyzes the root cause of Ellsberg-type choices. This class of problems shares the feature that at the time of the decision, t=m, the decision maker (DM) possesses partial information about the events/propositions of interest: DM knows the objective probabilities of some sub-class...

We examine a production-based asset pricing model with regime-switching productivity growth, learning and ambiguity. Both mean and volatility of the growth rate of productivity are assumed to follow a Markov chain with an unobservable state. The agent's preferences are characterized by the...

Probabilistic risk beliefs are key drivers of economic and health decisions, but people are not always certain about their beliefs. We study these "imprecise probabilities", also known as ambiguous beliefs. We show that imprecision is measurable separately from the levels of risk beliefs. People...

This paper analyzes the stability and distribution of ambiguity attitudes using a broad population sample. Using high-powered incentives, we collected six waves of data on ambiguity attitudes about financial markets—our main application—and climate change. Estimating a structural stochastic...

We elicit subjective ambiguous beliefs of an agent with ambiguity-sensitive preferences; in particular, as represented by the alpha-maxmin model. An important problem with the model is that it cannot be identified using observations from typical choice problems, as the preference parameter alpha...