Judicious management of uncertain risks: I. Developments and criticisms of risk analysis and precautionary reasoning

In situations of serious uncertain risk, precautionary assessment, decision-making and control may be inevitable. In this paper, the long and wide-ranging debate about the precautionary principle (PP) is surveyed in comparison to parallel developments of classical risk analysis. The 'new risks' provoking precaution typically are complex, often extensive in space and time, socially diverse, supposedly unlikely but highly uncertain, and potentially catastrophic. Classical risk analysis falls short of grasping such ill-defined problems validly enough for effective policy support. Similarly, the 'prudent' PP is criticised for its vagueness, multiple meanings and lack of practical elaboration. Despite their differences, however, risk-analytic and precautionary-principled approaches seem to be converging. On the way towards a decision-theoretic exposition (see follow-up paper), an integrative circumscription of the PP is proposed, which comprises 10 key issues for further elaboration. Logically, the 'pessimistic' PP is contrasted with its 'optimistic' counterpart, the venture principle (VP), which may be equally rational and/or inevitable in particular uncertain decision situations.