Combien valent les décès évités par la prévention ?

This paper concerns the difficulty of taking into account long term health effects of prevention policies in an economic valuation. The proposed methodology estimates the delay between the implementation of a policy and the achievement of all of the expected mortality-related health benefits. Benefits are assessed both in terms of life years gained and premature deaths avoided for two prevention policies: an air pollution abatement policy and a road safety policy. The main findings are that the relative comparison of the policies?' benefits is very sensitive to technical choices dealing with the method chosen to assess mortality benefits and the discount rate.Classification JEL : H43, I12, Q25