Abstract: The value of mortality risk reduction is an important component of the benefits of environmental policies. In recent years, the number, scope, and quality of valuation studies have increased dramatically. Revealed preference studies of wage compensation for occupational risks, on which analysts have primarily relied, have benefited from improved data and statistical methods. Stated preference research has improved methodologically and expanded dramatically. Studies are now available for several health conditions associated with environmental causes, and researchers have explored many issues concerning the validity of the estimates. With the growing numbers of both types of studies, several meta-analyses have become available that provide insight into the results of both methods. Challenges remain, including better understanding of the persistently smaller estimates from stated preference than from wage differential studies and of how valuation depends on the individual’s age, health status, and characteristics of the illnesses most frequently associated with environmental causes.

Abstract: In this paper, we examine the value of health risk reductions to Canadians in the context of clean and safe drinking water. The health risks we examine pertain both to microbial illnesses and/or deaths and bladder cancer illnesses and/or deaths. The cancer risks arise because chlorine, the most common disinfectant used to remove microbial contaminants, has been implicated in the production of trihalomethanes (a disinfection by-product linked to increases in bladder cancer cases). Under these circumstances, public health agencies face issues of risk–benefit valuation as well as risk–risk assessment. To address this policy issue, we undertook a panel-based Internet survey of 1,600 Canadians conducted in the summer of 2004 and presented respondents with text and graphical information regarding risk changes. We employed two valuation formats (contingent valuation and attribute-based stated choice) to elicit consumer preferences for public programs to reduce health risks associated with improved tap water. We also used multiple analytical methods, including willingness-to-pay space models, and examine a host of comparisons between contingent valuation and attribute-based methods to assess the effect of risk context on value. Our analysis of the stated preferences of consumers reveals several types of values that are of interest to policymakers. These include the value of mortality risk reductions and the value of morbidity risk reductions for both microbial contaminants and cancer. In addition, the value of reducing cancer risks versus microbial risks in a public context is revealed. Our results suggest that reducing mortality risks from microbial illness has greater value than reducing mortality risks from cancer. Similarly, overall microbial risk-reductions programs (mortality and morbidity) have higher value than cancer risk-reduction programs in this context. In addition, we provide separate estimates of the value of statistical life associated with cancer and microbial risks, in a public context, and the value of statistical illness cases associated with these two risks.

Abstract: Revealed preference evidence, especially based on wage-risk tradeoffs in the labor market, provides the primary empirical basis for analyses of the value of statistical life (VSL). This market evidence also provides guidance on how VSL varies with age. While labor market studies have generated conflicting evidence—some showing that VSL rises with age and others showing that VSL declines with age—more refined estimates that take into account the age variation in job fatality risks or life-cycle patterns of consumption show an inverted-U relation between the VSL and age. The value of a statistical life year shows a similar pattern and is not time-invariant. Applying estimates of the VSL-age relationship to an analysis of the Clear Skies initiative illustrates the implications of recognizing the age-VSL relationship.

Abstract: To resolve the theoretical ambiguity in the effect of age on the value of statistical life (VSL), this article uses a novel, age-dependent fatal risk measure to estimate age-specific hedonic wage regressions. VSL exhibits an inverted-U shaped relationship with age. In the year 2000 cross-section, workers’ VSL rises from $3.2 million (ages 18–24), to $9.9 million (35–44), and declines to $3.8 million (55–62). Controlling for birth-year cohort effects in a minimum distance estimator yields a peak VSL of $7.8 million at age 46 and flattens the VSL-age relationship. The value of statistical life-year also follows an inverted-U shape with age.

Abstract: This article develops the first measures of age-industry job risks to examine the age variations in the value of statistical life. Because of the greater risk vulnerability of older workers, they face flatter wage-risk gradients than younger workers, which we show to be the case empirically. Accounting for this heterogeneity in hedonic market equilibria leads to estimates of the value of statistical life-age relationship that follows an inverted-U shape. The estimates of the value of statistical life range from $6.4 million for younger workers to a peak of $9.0 million for those age 35-44, and then a decline to $3.7 million for those age 55-62. The decline of the estimated VSL with age is consistent with there being some senior discount in the Clear Skies Initiative analysis.

Abstract: We define the irreversibility effect and demonstrate its importance in problems involving investmentdecisions under uncertainty. We establish several analytical and numerical resultsthat suggest both that the effect holds more widely than generally recognized, and that anexisting result (Epstein’s Theorem) giving a sufficient condition for determining whether theeffect holds can be applied more widely than previously indicated, in particular to problemsinvolving intertemporally nonseparable benefit functions. We further show that a low elasticityof intertemporal substitution will however result in failure of the effect, but that theeffect will hold if the value of information increases in the degree of flexibility.

Abstract: A contingent valuation survey was conducted in Sizuoka, 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 the 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 regression. 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 environment policy analyses. This first-of-its-kind survey in Japan provides information directly useful for estimating the benefits of environmental and other policies that lower mortality risks to the general population and sub-groups with a variety of specific traits.

Abstract: Using results from two contingent valuation surveys conducted in Canada and the United States, we explore the effect of a latency period on willingness to pay (WTP) for reduced mortality risk using both structural and reduced form approaches. We find that delaying the time at which the risk reduction occurs by 10 to 30 years significantly reduces WTP for respondents aged 40 to 60 years. Additionally, we estimate implicit discount rates equal to 8% for Canada and 4.5% for the United States—both well within the range established previously in the literature.

Abstract: This paper analyzes uncertainties surrounding the benefits and costs of a policy to reduce nitrogen oxides (NOX) emissions from electricity generation in the eastern U.S. Under each of 18 scenarios examined, we find an annual policy would yield net benefits that are at least as great as those expected under the U.S. Environmental Protection Agency’s (EPA) currently planned seasonal policy. Preferred (midpoint) assumptions yield additional benefits of $724 million per year under an annual policy compared to a seasonal one (1997 dollars). The subset of 11 northeastern states benefit the most from an annual policy relative to a seasonal one, but relative net benefits are also positive in the remaining states in the region. An annual policy implemented on a national basis appears to be slightly less cost-effective than the EPA’s policy under midpoint assumptions but it is more cost-effective under half of the scenarios we examine.

Abstract:

Much of the justification for environmental rulemaking rests on estimates of the benefits to society of reduced mortality rates. This research aims to fill gaps in the literature that estimates the value of a statistical life (VSL) by designing and implementing a contingent valuation study for persons 40 to 75 years of age, and eliciting WTP for reductions in current and future risks of death. Targeting this age range also allows us to examine the impact of age on WTP and, by asking respondents to complete a detailed health questionnaire, to examine the impact of health status on WTP.

This survey was self-administered by computer to 930 persons in Hamilton, Ontario, in 1999. The survey uses audio and visual aids to communicate baseline risks of death and risk changes and are tested for comprehension of probabilities before being asked WTP questions. We credit these efforts at risk communication with the fact that mean WTP of respondents faced with larger risk reductions exceeds mean WTP of respondents faced with smaller risk reductions; that is, our respondents pass the external scope test.

Our mean WTP estimates for a contemporaneous risk reduction imply a VSL ranging approximately from $1.2 to $3.8 million (1999 C$), depending on the size of the risk change valued, which is at or below estimates commonly used in environmental cost-benefit analyses by the Canadian and the U.S. governments. Interestingly, we find that age has no effect on WTP until roughly age 70 and above (the VSL is about $0.6 million for this age group) and that physical health status, with the possible exception of having cancer, has no effect. We also find that being mentally healthy raises WTP substantially. In addition, compared with estimates of WTP for contemporaneous risk reductions, mean WTP estimates for risk reductions of the same magnitude but beginning at age 70 are more than 50% smaller.