Strong versions of the
Precautionary Principle (PP) require regulators to prohibit or impose technology
controls on activities that pose uncertain risks of possibly significant environmental
harm. This decision rule is conceptually unsound and would diminish social welfare.
Uncertainty as such does not justify regulatory precaution. While they should
reject PP, regulators should take appropriate account of societal aversion to
risks of large harm and the value of obtaining additional information before
allowing environmentally risky activities to proceed.