Radiology

Mathematical economics

Social choice theory

Mathematics

Regret

Statistics

Counterfactual thinking

Ambiguity aversion

Axiom independence

Econometrics

Management

Psychology

Economics

Choice set

Axiom

Microeconomics

Set (abstract data type)

Weighting

Independence of irrelevant alternatives

Programming language

Expected utility hypothesis

Geometry

Computer science

Task (project management)

Ambiguity

Preference

Certainty

Medicine

Social psychology

Journal of Economic Theory

We present a set of experiments testing for incomplete preferences due to uncertainty. In a first experiment, we observe that approximately half of the participants exhibit a choice pattern inconsistent with models assuming complete preferences and Certainty Independence (CI). To understand these participants' behavior, in a second experiment, we design a decision task that distinguishes between models assuming complete preferences and relaxing CI and models of incomplete preferences under uncertainty. We find that about half of the participants in question exhibit behavior consistent with incomplete preferences, about one third shows behavior consistent with a preference for randomization between risky and ambiguous prospects, and the remaining participants' behavior is consistent with both types of preferences. In further experiments we find that the observed choice pattern cannot be attributed to probability weighting, choice mistakes, regret aversion or intransitive indifference under risk and certainty. We also show that the observed behavior is robust to a prize variation in the ambiguous prospect.

Revealed preferences under uncertainty: Incomplete preferences and preferences for randomization