Decision-analytic refinements of the precautionary principle

In public decision making about uncertain technological hazards, the precautionary principle calls for prompt protective action rather than delay of protections until scientific uncertainty is resolved. The precautionary principle has a sound basis in decision theory, particularly in situations where the potential hazards are serious and the costs of protective actions are tolerable. This article suggests that the precautionary principle should be refined to address three complications: (1) situations where the exposures to be reduced or prevented may have beneficial as well as hazardous consequences; (2) situations where the protective action itself will create potential hazards; and (3) situations where targeted research investments, coupled with delay of protective action, are likely to support wiser public decisions than prompt protective action. Each of these complications is shown to be relevant to contemporary policy debates about application of the precautionary principle. The usefulness of the precautionary principle in public decision making will be enhanced if these decision-analytic refinements are adopted in formal definitions of the principle.