Different models of uncertainty aversion imply strikingly different economic behavior. The key to understanding these differences lies in the dichotomy between first-order and second-order ambiguity aversion which I define here. My definition and its characterization are independent of specific...

Although much of the theoretical literature on ambiguity works under the assumption of uncertainty aversion, experimental evidence suggests that it is not a universal behavioral trait. This paper introduces and axiomatises the family of α-UA (for α-Uncertainty Attitude) preferences: a simple...