Overconfidence is the most prevalent judgment bias. Several studies find that overconfidence can lead to suboptimal decisions on the part of investors, managers, or politicians. This chapter explains which effects are usually summarized as overconfidence, shows how to measure these effects, and...

There are many important decision problems where learning through experimentation is costly or impossible. In these situations, individuals may try to learn from observing the outcomes of others who have made similar decisions. Often, however, information about others comprises a selected...