WTP estimates of $40-400 for a 4-in-100,000 risk reduction (translating to a VSL of $1-10 million). Turning the annual mortality-rate changes and WTP values into saved lives and values per life saved is a mathematical transformation that seems convenient for summary tables and policy assessments, but can be misleading and can obscure the underlying derivation and appropriate interpretation of the studies. It also ignores the effect of life-expectancy changes on the population composition over time, and this will cause the annual number of deaths to decrease at first and then to return to its previous level or even increase over time (e.g., Miller and Hurley 2003).
The health-related research and valuation research recommended in this report should be addressed as part of EPA’s research strategy for estimating the mortality risk-reduction benefits of reducing exposure to ambient ozone. However, the research needs should not be viewed as a basis for postponing consideration of ozone mortality relationships in benefits assessment until more information is obtained. Also, it would be a mistake to assume that the committee’s discussion of uncertainties and research needs broadly applies to the current understanding of air pollution and health in general. For example, this report has indicated where there is a greater understanding of many aspects of PM-mortality relationships relative to those for ozone. Continued enhancement of knowledge and methods for valuation of ozone mortality risk reduction benefits will inform future regulatory decision making and help in understanding the relative importance and value of effects caused by various pollutants.