Communicating Uncertainty for Regulatory Decisions

To compare immediate regulatory options, the decision maker needs a current assessment of outcomes (e.g., health impact of a proposed standard), including, say, a mean and a range of uncertainty. To evaluate an option to delay the decision, he needs to appreciate how that current assessment might change, introducing a higher order uncertainty. This paper explores graphic and other devices for communicating this elusive distinction, with a view to clarity, action orientation and logical soundness. Other common interpretations of uncertainty are treated as secondary for regulatory purposes. A nuclear backfit decision is used as an example.