JUDGING CUMULATIVE RISK

The accuracy of young adults' perceptions of how cumulative risks to l ift, health, and property change over time was tested by asking subjec ts to judge the long-term probabilities associated with different peri ods of exposure to risks that are very small in the short term. Proces s analyses revealed evidence that strategy choice and associated accur acy depended on context and framing variables. Subjects asked to judge conjunctive probabilities adopted a variety of strategies, all of whi ch failed to yield consistently accurate long-term probability judgmen ts. However, subjects asked to judge disjunctive probabilities often r eframed the probability questions into questions about the expected nu mber of times the hazard would strike, which they could answer more ac curately. Implications of the research for promoting public understand ing of the long-term implications of cumulative risks are discussed.