Many theories of updating under ambiguity assume either dynamic consistency or consequentialism to underpin behaviorally the link between conditional and unconditional preferences. To test the descriptive validity of these rationality concepts, we conduct a dynamic extension of Ellsbergʼs...

We show that for many classes of symmetric two-player games, the simple decision rule “imitate-if-better” can hardly be beaten by any strategy. We provide necessary and sufficient conditions for imitation to be unbeatable in the sense that there is no strategy that can exploit imitation as a...