Behavioral economists assume that people make decisions based on the perceived probabilities of events. Behavioral experiments, interpretations, and the policies they inform should therefore depend on information about popular perceptions about likelihoods. This grant funds work by Paul Slovic of the University of Oregon and co-principal investigator Howard Kunreuther of the Wharton School to field surveys that will collect data on public perceptions of the probabilities for a host of important events, including nuclear war, chemical attack, opioid addiction, school shootings, as well as the mass adoption of driverless cars or e-cigarettes. Opinions about more than a hundred hazards will be elicited. In addition, Slovic and Kunreuther will conduct textual analyses based on the frequency that Google News describes a given hazard using words with high emotional valence. Last, the team will field a series of experiments designed to probe how people act on those perceptions and what can be done to help everyone make better estimates and better decisions.