Decision processes for low probability events: Policy implications

This survey describes the impact of judgements and choices about low probability, high consequence events on the policymaking process. Empirical evidence indicates that normative models of choice, such as expected utility theory, are inadequate descriptions of individual choices. The ambiguity of low probabilities also affects decisions in ways that are not normative. Further, people exhibit biases in judgments about risks and probabilities. These findings have stimulated development of new theories, such as prospect theory and generalized utility theories incorporating attributes such as regret. The authors survey many of these empirical results and explore their implications for policy. They consider the role of information, economic incentives, compensation, and regulation in inducing socially desirable effects through the reframing of outcomes. They suggest that surveys and experiments can help analysts better understand the decision process for low probability events and design more effective public policies.