Age, health, and the willingness to pay for mortality risk reductions: a contingent valuation survey of Shizuoka, Japan, residents

A contingent valuation survey was conducted in Shizuoka, Japan, to estimate the willingness to pay (WTP) for reductions in the risk of dying and calculate the value of statistical life (VSL) for use in environmental policy in Japan. Special attention was devoted to the effects of age and health characteristics on WTP. We find that the VSLs are somewhat lower (103 to 344 million yen) than those found in a virtually identical survey applied in some developed countries. These values were subject to a variety of validity tests, which they generally passed. We find that the WTP for those over age 70 is lower than that for younger adults, but that this effect is eliminated in multiple regressions. Rather, when accounting for other covariates, we find that WTP generally increases with age throughout the ages in our sample (age 40 and over). The effect of health status on WTP is mixed, with WTP of those with cancer being lower than that of healthy respondents, while the WTP of those with heart disease is greater. The VSLs for future risk changes are lower than those for contemporaneous risk reductions. The implicit discount rates of 5.8%–8.0% are relatively larger than the discount rate regularly used in environmental policy analyses. This survey is the first of its kind in Japan, and provides information that is directly useful for estimating the benefits of environmental and other policies that lower mortality risks to the general population and subgroups with a variety of specific traits.