Ellsberg?s famous paradox [1961] focused attention on the importance of the precision of the probabilities underlying risky choice. Following his seminal work numerous studies have demonstrated that people are generally averse to imprecisely specified (vague) probabilities. In many important...

This paper focuses on decisions under ambiguity. Participants in a laboratory experiment made decisions in three different settings: (a) individually, (b) individually after discussing the decisions with two others, and (c) in groups of three. We show that groups are more likely to make...

We conducted an experimental study of price competition in a duopolistic market. The market was operationalized as a repeated game between two “teams” with one, two, or three players in each team. Each player simultaneously demanded a price, and the team whose total asking price was smaller...

In a series of experiments, Bar-Hillel and Budescu (1995) failed to find a desirability bias in probability estimation. The World Cup soccer tournament (of 2002 and 2006) provided an opportunity to revisit the phenomenon, in a context where wishful thinking and desirability bias are notoriously...

The Recognition Heuristic (Gigerenzer \& Goldstein, 1996; Goldstein \& Gigerenzer, 2002) makes the counter-intuitive prediction that a decision maker utilizing less information may do as well as, or outperform, an idealized decision maker utilizing more information. We lay a theoretical foundation...