In this paper, the assumption of monotonicity of Anscombe and Aumann (1963) is replaced by an assumption of monotonicity with respect to first-order stochastic dominance. I derive a representation result where ambiguous distributions of objective beliefs are first aggregated into “equivalent...

We report a portfolio-choice experiment that enables us to estimate parametric models of ambiguity aversion at the level of the individual subject. The assets are Arrow securities that correspond to three states of nature, where one state is risky with known probability and two states are...

A new laboratory experiment is designed to identify the best theories for describing decisions under risk. The experimental design has two noteworthy features: a representative sample of binary choice problems (for fair comparison across theories) and a lottery set with a small number of...

This chapter reviews developments in the theory of decision making under risk and uncertainty, focusing on models that, over the last 40 years, dominated the theoretical discussions. It also surveys some implications of the departures from the “linearity in the probabilities” aspect of...

Prior research suggests that those who rely on intuition rather than effortful reasoning when making decisions are less averse to risk and ambiguity. The evidence is largely correlational, however, leaving open the question of the direction of causality. In this paper, we present experimental...

This paper experimentally investigates individual information acquisition and decisions in ambiguous situations in which the degree of ambiguity can endogenously and individually be decreased by the subjects. In particular, I analyze how risk aversion, ambiguity attitude and personality traits...

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...

This paper focuses on information acquisition and individual decision making in ambiguous situations and presents a novel experimental design which may help to tackle open questions from a fresh perspective. Instead of giving subjects the choice between risky and ambiguous Ellsberg urns, we let...

An extensive literature has studied ambiguity aversion in economic decision making, and how ambiguity aversion can account for empirically observed violations of expected utility-based theories. Almost all relevant applied models presume a general dislike of ambiguity. In this paper, we provide...