People often need to choose between alternatives with known probabilities (risk) and alternatives with unknown probabilities (ambiguity). Such decisions are characterized by attitudes towards ambiguity, which are distinct from risk attitudes. Most studies of ambiguity attitudes have focused on...

When people are asked to estimate the probabilities for an exhaustive set of more than two events, they often produce probabilities that add up to more than 100%. Potential determinants for such additivity neglect are explored in four experiments. Additive responses vary between experimental...

Micro-aggregation is a frequently used strategy to anonymize data before they are released to the scientific public. A sample of a continuous random variable is individually micro-aggregated by first sorting and grouping the data into groups of equal size and then replacing the values of the...

People exhibit excessive confidence in visually-based estimates, which in turn biases decision making. Three experiments support this assertion. Experiment 1 shows a strong impact of presentation format on estimation of proportions. Experiment 2 shows that people rely on these erroneous...

Empirical studies of horse race betting in the US, the UK, Australia, and Germany have empirically established the so called favorite-longshot bias. It was found that bets on longshots on average lose much more than bets on favorites. The theoretical literature on wagering markets has offered a...