Formalization and Applications of the Precautionary Principles

A formalization of the Precautionary Principle is given here : We formalize scientific knowledge on the likelihood of events in the state space and the concepts of scientifically unambiguous events and acts. We give a definition of a non-precautionary social planner as a Savage Expected Utility maximizer who evaluates acts relative to a baseline, called "business as usual", and who disregards scientifically ambiguous acts, and we show that, for a wide class of preferences for the representative agent, non-precautionary decision making is sub-optimal. A discussion of this formalization is given in the context of national and international debates on Precautions, in the fields of Climate Change, of WTO arbitrages, and of the safety regulations of chemical products.