Subjects are asked to report their confidence in their own decisions regarding the Ellsberg three color urn. Subjective confidence is measured via a 5 point Likert scale. Surprisingly, subjects are more confident in their answer for the more complicated two color question, compared to the simple...

We provide an evolutionary foundation to evidence that in some situations humans maintain optimistic or pessimistic attitudes towards uncertainty and are ignorant to relevant aspects of the environment. Players in strategic games face Knightian uncertainty about opponents' actions and maximize...

We provide an evolutionary foundation to evidence that in some situations humans maintain either optimistic or pessimistic attitudes towards uncertainty and are ignorant to relevant aspects of the environment. Players in strategic games face Knightian uncertainty about opponents' actions and...

We consider a decision maker who is unaware of objects to be sampled and thus cannot form beliefs about the occurrence of particular objects. Ex ante she can form beliefs about the occurrence of novelty and the frequencies of yet to be known objects. Conditional on any sampled objects, she can...

To make predictions with theories, usually we assume an individual's characteristics such as uncertainty preferences to be stable over time. In this paper, we analyze the stability of ambiguity preferences experimentally. We repeatedly elicit ambiguity attitudes towards multiple 3-color Ellsberg...

Traditionally, real experiments testing subjective expected utility theory take for granted that subjects view the Ellsberg task as a one-person decision problem. We challenge this view: Instead of seeing the Ellsberg task as a one-person decision problem, it can be perceived as a two-player...