We report on an experiment in which subjects choose actions in strategic games with either strategic complements or substitutes against a granny, a game theorist or ther subjects. The games are selected in order to test predictions on the comparative statics of equilibrium with respect to...

In [7] Ghirardato, Macheroni and Marinacci (GMM) propose a method for distinguishing between perceived ambiguity and the decision-maker's reaction to it. They study a general class of preferences which they refer to as invariant biseparable. This class includes CEU and MEU. They axiomatize a...

This paper considers the impact of ambiguity in strategic situations. It extends the earlier literature by allowing for optimistic responses to ambiguity. Ambiguity is modelled by CEU preferences. We propose a new solution concept for players who may express ambiguity-preference. Then we study...