Many papers have reported behavioral biases in belief formation that come on top of standard game-theoretic reasoning. We show that the processes involved depend on the way participants reason about their beliefs. When they think about what everybody else or another "unspeci fied" individual is...

This study analyzes investors' perception of placebic information and its impact on stock price estimates. We initiate a questionnaire-based stock price forecast competition among 196 undergraduate students in business administration. We show that placebic information increases the perceived...

I show how irrational ideas and rumors can drive asset prices - not because anyone believes them, but because they are commonly known without being common knowledge. The phenomenon is driven by short-term market participants who are well-informed about the information that others have, and who...