As illustrated by the famous Ellsberg paradox, many subjects prefer to bet on events with known rather than with unknown probabilities, i.e., they are ambiguity averse. In an experiment, we examine subjects’ choices when there is an additional source of ambiguity, namely, when they do not know...

Most models of ambiguity aversion satisfy Anscombe-Aumann's Monotonicity axiom. This paper proposes a test of Monotonicity, the Allais Horse Race. It is an adaptation of the Allais paradox to a setting with both subjective and objective uncertainty. Viewed as a thought experiment, the Allais...

We implement an experiment to elicit subjects’ ambiguity attitudes in the spirit of Ellsberg’s three-color urn. The procedure includes three design elements that (together) have not been featured in similar experiments: Strict ambiguity preferences, a single decision, and a mechanical...

Prospect theory (PT) is the dominant descriptive theory of decision making under risk today. For the modeling of choices, PT relies on a psychologically founded separation of risk attitudes into attitudes towards outcomes, captured in a value function; and attitudes towards probabilities,...