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...

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...