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.

It is shown that a win-stay, lose-hift behavior rule with endogenous aspiration levels yields cooperation in a certain class of games. The aspiration level in each round equals the current population average. The class of games includes the prisoner's dilemma and Cournot oligopoly and thus...