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...

Bubbles in asset markets have been documented in numerous experiments. Most experiments in which bubbles occur feature a declining fundamental value. This feature has been criticized for being atypical of real financial markets. Here, we experimentally study other ingredients for bubble...

We describe an ambiguity hedging problem in Ellsberg experiments, where combinations of individually ambiguous bets eliminate aggregate ambiguity, and which may yield incorrect classifications of ambiguity averse subjects. We propose a new classification consistent with this hedging possibility.