We introduce a simple, easy to implement instrument for jointly eliciting risk and ambiguity attitudes. Using this instrument, we structurally estimate a two-parameter model of preferences. Our findings indicate that ambiguity aversion is significantly overstated when risk neutrality is assumed....

A decision maker (DM) is asked to make choices from a set of acts, which entail both risk and uncertainty in the sense of knight (1921). Extending Raiffa's (1961) argument I show that, provided the DM can choose acts objectively randomly (by flipping her own fair coin, for instance), provided...

The moderate utility model represents the probability of choosing an option in a pairwise comparison as an increasing function of utility difference divided by a dissimilarity metric. We provide a single, directly testable property that characterizes the model: choices are moderately transitive....

This paper presents a new decision theory for modelling choice under risk. The new theory is a two-parameter generalization of expected utility theory. The proposed theory assumes that a decision maker: 1) behaves as if maximizing expected utility; but 2) may experience disappointment (elation)...

We propose a single evolutionary explanation for the origin of several behaviors that have been observed in organisms ranging from ants to human subjects, including risk-sensitive foraging, risk aversion, loss aversion, probability matching, randomization, and diversification. Given an initial...