Health benefits induced by environmental quality: Are private costs negligible?

For a complete estimation of morbidity effects associated with environmental damages, the paper pleads in favour of the use of two methods: the cost of illness method (COI) and the contingent valuation method(CVM). Indeed these methods are complementary, COI is used to asses the "social cost" (medical expenses, lost wages) and CVM to value the "private cost" (disutility associated with the symptoms, pain, restricted activity). Moreover we show in the case of light symptoms induced by air pollution that private cost is at least as important as the social cost. Neglecting the private cost leads to an underestimation of health costs. In a cost-benefit analysis point of view, such an underestimation could lead to the opposite public decision.