Individuals' estimates of the risks of death: Part II - New evidence

Using new survey data, we test the hypothesis that individuals' perceptions of health and safety risks are unbiased. While we find that respondents' estimates of those risks are sensitive to the information they are given to anchor their responses, we find no evidence to support the widely held view that people tend to underestimate the frequency of relatively common risks. The slight tendency for respondents to overestimate the frequency of extremely unlikely events can plausibly be interpreted as truncation bias. Overall, the accuracy of our subjects' estimates varies in a manner that is fully consistent with simple conjectures about the health and safety information that is of greatest relevance to them in the conduct of their lives. The marked difference between the results of our survey and those of previous studies appears to be attributable to the practical implications of costly information and the common failure of investigators to account for the fact that rational individuals will choose to acquire less than full information about many uncertain events.