The role of risk aversion and lay risk in the probabilistic externality assessment for oil tanker routes to europe

Oil spills are a major cause of environmental concern, in particular for Europe. We extend the traditional approach of assessing the welfare losses for individuals potentially affected by an oil spill, by taking into full account the implications of the probabilistic nature of the related externalities. Our approach differs from the traditional one in three respects: it allows for risk aversion; it adopts an ex-ante rather than an ex-post perspective; it allows for subjective oil-spill probabilities (held by the lay public) more than for expert-assessed probabilities. We illustrate this methodology with a case study on the Aegean Sea.