Risk Assessment and Uncertainty

Abstract

Risk assessments done by the Ford Foundation-Mitre Corporation and the Union of Concerned Scientists agree on the hazard probabilities and consequences associated with commercial nuclear fission, but make opposed recommendations regarding using atomic energy to generate electricity. The UCS risk analysis decided against use of the technology; the Ford-Mitre study advised in favor of it (Union of Concerned Scientists 1977; Nuclear Energy Policy Study Group 1977; Cooke 1982, p. 334).The two studies agreed on the data but made different policy recommendations because they followed different methodological rules at the third, risk-evaluation, stage of assessment. (The first two stages are risk identification and risk estimation.) The Ford-Mitre research was based on the widely accepted Bayesian decision criterion that it is rational to choose the action with the best expected value or utility, where ‘expected value’ or ‘expected utility’ is defined as the weighted sum of all possible consequences of the action, and where the weights are given by the probability associated with each consequence.