α - Maxmin Expected Utility with Non-Unique Prior

Preferences over acts have an α-Maxmin Expected Utility (α-MEU) representation if they can be represented by an α-mix between the worst and the best expected utility over a set or priors. The case α=1 is characterized in Gilboa and Schmeidler (1989). Inspired by their representation result, two novel types of axioms are introduced: α-Monotonicity and α-Uncertainty Attitude. Replacing the axioms Monotonicity and Uncertainty Aversion in Gilboa and Schmeidler (1989) by these axioms provides a characterization of α-MEU preferences for α not 1/2