The decision to accept or to reject an empirical hypothesis concerning the risks and hazards of a pesticide requires assessing the cost's of error if the wrong decision is taken. The assessment of such costs involves scientists in problems which are closely related to those which policy‐makers face in deciding what to do in view of the information provided by scientists. These problems include the unforeseeable effects of agricultural technologies, the assessments of costs and benefits, and the choice of decision (...) rule to use in policy formation. I conclude that the combined impact of these problems motivates the use of prudentially weighted decision rules in forming policies which regulate the use of pesticides, and it motivates the development of bio‐environmental alternatives to chemically based pest control policies. (shrink)