The heterogeneity of the value of statistical life: Introduction and overview

The refinement in worker fatality risk data used in hedonic wage studies and evidence from new stated preference studies have facilitated the exploration of the heterogeneity of the value of statistical life (VSL). Although the median VSL estimate for workers is $7–$7–8 million, the VSL varies considerably within the worker population. New estimates of the income elasticity of VSL are 1.0 or above, which are consistent with theoretical models linking VSL to the coefficient of relative risk aversion. The specific relationship between VSL and risk aversion is, however, more complex than previously understood. Age differences in VSL are substantial, with young children being accorded especially high VSL amounts. The public’s willingness to pay to reduce risks is reduced if those being protected are perceived as being blameworthy due to their responsibility for contributing to the risk.     

Willingness to accept equals willingness to pay for labor market estimates of the value of a statistical life

Our research clarifies the conceptual linkages among willingness to pay for additional safety, willingness to accept less safety, and the value of a statistical life (VSL). We present econometric estimates using panel data to analyze the VSL levels associated with job changes that may affect the worker’s exposure to fatal injury risks. Our baseline VSL estimates are $7.7 million and $8.3 million (Y$2001). There is no statistically significant divergence between willingness-to-accept VSL estimates associated with wage increases for greater risks and willingness-to-pay VSL estimates as reflected in wage changes for decreases in risk. Our focal result contrasts with the literature documenting a considerable asymmetry in tradeoff rates for increases and decreases in risk. An important implication for policy is that it is reasonable to use labor market estimates of VSL as a measure of the willingness to pay for additional safety.     

Anchoring biases in international estimates of the value of a statistical life

U.S. labor market estimates of the value of a statistical life (VSL) were the first revealed preference estimates of the VSL in the literature and continue to constitute the majority of such market estimates. The VSL estimates in U.S. studies consequently may have established a reference point for the estimates that researchers analyzing data from other countries are willing to report and that journals are willing to publish. This article presents the first comparison of the publication selection biases in U.S. and international estimates using a sample of 68 VSL studies with over 1000 VSL estimates throughout the world. Publication selection biases vary across the VSL distribution and are greater for the larger VSL estimates. The estimates of publication selection biases distinguish between U.S. and international studies as well as between government and non-government data sources. Empirical estimates that correct for the impact of these biases reduce the VSL estimates, particularly for studies based on international data. This pattern of publication bias effects is consistent with international studies relying on U.S. estimates as an anchor for the levels of reasonable estimates. U.S. estimates based on the Census of Fatal Occupational Injuries constitute the only major set of VSL studies for which there is no evidence of statistically significant publication selection effects. Adjusting a baseline bias-adjusted U.S. VSL estimate of $9.6 million using estimates of the income elasticity of the VSL may be a sounder approach for generating international estimates of the VSL than relying on direct estimates from international studies.     

Policy relevant heterogeneity in the value of statistical life: New evidence from panel data quantile regressions

We examine differences in the value of statistical life (VSL) across potential wage levels in panel data using quantile regressions with intercept heterogeneity. Latent heterogeneity is econometrically important and affects the estimated VSL. Our findings indicate that a reasonable average cost per expected life saved cut-off for health and safety regulations is 7 million to7 million to 8 million per life saved, but the VSL varies considerably across the labor force. Our results reconcile the previous discrepancies between hedonic VSL estimates and the values implied by theories linked to the coefficient of relative risk aversion. Because the VSL varies elastically with income, regulatory agencies should regularly update the VSL used in benefit assessments, increasing the VSL proportionally with changes in income over time.     

Valuing the risk of workplace sexual harassment

Using data on sexual harassment charges filed with the Equal Employment Opportunity Commission, I calculate the risk of sexual harassment by gender, industry, and age and establish that white females, but not nonwhite females, receive a compensating wage differential for exposure to a higher risk of sexual harassment. I use this risk premium to calculate the value of statistical harassment (VSH) in a manner analogous to the calculation of the value of statistical life (VSL). The VSH is around $7.6 million, about three-quarters of the size of the most-commonly cited levels of the VSL, and far above the maximum damages award for sexual harassment available under federal law. Boosting the maximum damages award to equal the VSH would create the appropriate economic incentives for organizations to deter sexual harassment.     

Elicitation of health values from mortality risk reduction

There are concerns regarding uncertainty about the accuracy of applying available empirical willingness-to-pay (WTP) estimates for reducing accidental deaths to value changes in risks of pollution-related deaths. In this study, we develop a theoretical model on defining WTP, and its determinants, and derive WTP estimates for changes in pollution-related mortality risks with varying morbidity and timing attributes. A survey is designed and conducted with 100 subjects. Each subject was to complete five choice sets and provided a range of implicit values of statistical life (VSL). The choices are estimated using the logit procedure. And, using the results of estimated multinomial logit model, the VSL is estimated to about $6.2 million.     

Risk Perceptions and Value of a Statistical Life for Air Pollution and Traffic Accidents: Evidence from Bangkok,Thailand

This paper presents results of two contingent valuation surveys conducted in Bangkok measuring individuals’ willingness to pay (WTP) to reduce mortality risk arising from two risk contexts: air pollution traffic accidents Results from the risk perception survey disclose that respondents view the two risks differently. WTP to reduce air pollution risk is influenced by degrees of dread, severity, controllability and personal exposure, while WTP to reduce traffic accident risk is influenced by perceived immediate occurrence. Nevertheless, the value of a statistical life (VSL) for both air pollution and traffic accidents are comparable (US$0.74 to $1.32 million and US$0.87 to $1.48 million, respectively). This indicates that the risk perception factor alone has little impact on the VSL, a finding similar to previous studies using program choice indifferences.JEL Classification: I18, D61, J17, J28     

On the Value of Changes in Life Expectancy: Blips Versus Parametric Changes

We estimate the value of a ‘blip’, i.e. an immediate small reduction, in the hazard rate for a random sample of Swedes. Since the risk reduction is age-independent (2 ‘extra saved lives’ out of 10,000 during the next year), we can examine how the value of a statistical life varies with age. We also show how blip data can be used to obtain a lower bound for the value of a permanent change in an individual's hazard rate. The value of a life exhibits an inverted-U shape with respect to age, peaking at the age of 40, and lies within the $3 to $7 million interval where most reasonable estimates are clustered according to Viscusi's (1992) survey.     

Admissible utility functions for health, longevity, and wealth: integrating monetary and life-year measures

The value of reducing health and mortality risks is often measured using value per statistical life (VSL) or one of several life-year measures (e.g., life years, quality-adjusted life years, disability-adjusted life years). I derive the utility function that is admissible when preferences for health and longevity, conditional on wealth, are consistent with any life-year measure (LYM) and examine the implications for marginal willingness to pay (WTP) for increases in health, longevity, and current-period survival probability. I conclude that marginal WTP for any LYM is decreasing and that VSL is increasing in the LYM. These results imply that cost-effectiveness analysis using a fixed monetary value per LYM is not consistent with economic welfare theory and that the benefit of a health improvement cannot be calculated by multiplying the change in a LYM by a constant.     

Individual and Household Values of Mortality Reductions with Intrahousehold Bargaining

I derive alternative measures of maximum willingness to pay (WTP) and value of statistical life (VSL) for selfish members of two-person households who bargain efficiently over consumption of individual and household goods. There is then no systematic bias in letting one member conduct the valuation on behalf of the household. Public-good VSL may exceed private-good VSL when each member attaches (selfish) preferences to survival of the spouse, and to any income from a surviving spouse in period 2. When period 2 is a retirement period and household members’ incomes are fixed, interview surveys tend to overvalue VSL due to ignored negative effects of own survival on private of public pension budgets.JEL Classification: I12, G22, J17     

Precautionary behavior and willingness to pay for a mortality risk reduction: Searching for the expected relationship

This paper examines within-sample correlation between six different precautionary behaviors and stated willingness to pay for a mortality risk reduction. The paper also shows estimates of the value of a statistical life based on seat belt and bicycle helmet use as well as based on the stated willingness to pay for a risk reduction in traffic mortality. Contrary to the theoretical expectations, no correlation is found between precautionary behavior and stated willingness to pay. One major explanation is that females and the elderly take more precaution, but state a lower WTP for a risk reduction. The estimates of VSL from the different approaches are $11.0 million, $5.0 million and $2.8 million from stated WTP, bicycle helmet use and seat belt use, respectively.

Reference points,loss aversion,and contingent values for auto safety

This article is concerned with the possible role of reference points and loss aversion (as suggested by prospect theory) in subjects' judgments about the value of increments and decrements in automobile safety. The contingent valuation method is employed in two experiments, both of which consider subjects' willingness-to-pay (WTP) for increased safety and compensation demanded (CD) for decreased safety in hypothetical new vehicle purchases. The results establish that disparities exist in subjects' WTP and CD values for the same increment of auto safety, even for a close-to-market context such as hypothetical new vehicle purchases. The results also indicate that evaluations can be manipulated by changing the perception of the reference point: losses can be recast as forgone gains and forgone gains as losses, altering (or even eliminating) differences between WTP and CD values.I would like to thank Mark Kamlet, Greg Fischer, and Granger Morgan for advice and help in structuring the research for the first experiment; Paul Slovic and Jack Knetsch for suggestions regarding the structure and content of the second experiment; Robin Gregory and two anonymous referees for insightful comments on earlier drafts; and the subjects who provided their time in the two experiments. Michael McNickle provided able research assistance for the second experiment. The survey for the first experiment was partially supported by the Program for Technology and Society at Carnegie Mellon University, with funds from the Andrew W. Mellon Foundation.     

Valuing Mortality-Risk Reduction: Using Visual Aids to Improve the Validity of Contingent Valuation

We investigate the validity of contingent valuation (CV) estimates of the value per statistical life (VSL). We test for sensitivity of estimated willingness to pay (WTP) to the magnitude of mortality-risk reduction and for the theoretically predicted proportionality of WTP to risk reduction using alternative visual aids to communicate risk. We find that WTP is sensitive to the magnitude of risk reduction for independent subsamples of respondents presented with each of three alternative visual aids, but not for the subsample presented with no visual aid. Estimated WTP is consistent with proportionality to risk reduction for the subsamples presented with a logarithmic scale or an array of 25,000 dots, but not for the subsample receiving a linear scale. These results suggest that CV can provide valid estimates of WTP for mortality-risk reduction if appropriate methods are used to communicate the risk change to respondents.     

On the validity of the estimates of the VSL from contingent valuation: Evidence from the Czech Republic

Journal of Risk and Uncertainty - We assess the reliability and validity of estimates of the Value per Statistical Life (VSL) from contingent valuation by administering the same contingent...     

Background Risks and the Value of a Statistical Life

We examine the effects of background mortality and financial risks on an individual's willingness to pay to reduce his mortality risk (the value of statistical life or VSL). Under reasonable assumptions about risk aversion and prudence with respect to wealth in the event of survival and with respect to bequests in the event of death, background mortality and financial risks decrease VSL. The effects of large mortality or financial risks on VSL can be substantial, but the effects of small background risks are negligible. These results suggest that the commonplace failure to account for background risk in evaluating VSL is unlikely to produce substantial bias in most applications.     

Do Life-Saving Regulations Save Lives?

Life-saving regulations may be counter-productive since they have an indirect mortality effect through the reduction in disposable income. This paper estimates the effect of income on mortality, controlling for the initial health status and a host of personal characteristics. The analysis is based on a random sample of the adult Swedish population of over 40,000 individuals followed up for 10–17 years. The income loss that will induce an expected fatality is estimated to be $6.8 million when the costs are borne equally among all adults, $8.4 million when the costs are borne proportionally to income and $9.8 million when the costs are borne progressively to income.     

The Fatality Risks of Sport-Utility Vehicles,Vans, and Pickups Relative to Cars

This paper examines the public health consequences of the regulatory subsidy given to light trucks. The empirical challenge is to disentangle the causal effects of light trucks from the selection bias that may occur due to drivers sorting into different vehicle types depending on their unobservable characteristics. I address this by using state variation of snow depth as an instrumental variable for vehicle miles traveled of light trucks and cars. This instrument has strong first-stage explanatory power. Since snow depth is likely a direct determinant of crashes, I meet the exclusion criteria by restricting the dependent variable to those crashes that occurred in the summer. My findings suggest that, given a crash, light trucks are more dangerous to others but less dangerous for those driving them. However, I also find that light trucks are more likely to crash than cars, which neutralizes the safety advantage to those who drive them. My estimates for aggregate fatalities suggest that a world of light trucks leads to substantially more fatalities than a world of cars.     

A Choice Experiment Approach to the Valuation of Mortality

This paper presents an integrated framework for evaluating the reduction of several types of mortality risk using a Choice Experiment (CE) approach, a type of stated preference technique. Using this approach, we can distinguish the marginal willingness to pay (MWTP) for the amount of risk reduction from the MWTP for the opportunity of risk reduction and therefore calculate the “Quantity-based” Value of a Statistical Life. The risks in our survey include mortality risks due to accident, cancer, and heart disease. The Quantity-based VSL is calculated to be 350 million JPY (in 2002 Japanese Yen, about 2.9 million US dollars). Furthermore, we analyzed the influence of subjective risk perception and population characteristics of the respondents on their MWTP. Estimated results suggest that it is unnecessary to adjust the VSL according to the differences in the type of risk if the VSL is calculated using an adequate approach. However, adjustments for the timing of risk reduction and population characteristics are found to be significant for the execution of benefit transfer.JEL Classification: I18, D81, J17     

A Comparison of the Effects of Material and Environmental Values on Vehicle Ownership

The results of a 1988 survey of Brisbane residents demonstrate a consistent linkage between the respondent's values and their preferences for vehicle ownership and use. Through the use of the ‘Dominant Social Paradigm’ - ‘New Environmental Paradigm’ theoretical framework (e.g. Cotgrove 1982) and the testing of ‘known groups’ (business people and members of the Rainbow Alliance) the following pattern emerged. The businesspeople were less willing to conserve fuel, and were more concerned with ‘comfort’ considerations when purchasing a motor vehicle than the Rainbow Alliance respondents who were more interested in utilitarian aspects. When subsamples with similar demographic/socioeconomic characteristics (males, respondents aged 35–49 years, respondents with household incomes between $20 000 and $49 999) were compared, the Rainbow Alliance respondents were more likely to own older, less valuable vehicles with small engines and manual transmissions. The businesspeople were more likely to own air-conditioned vehicles with poor fuel economy. This finding is an example of how people's values influence their vehicle purchasing decisions and is useful to policy-makers seeking to improve the efficiency of Australia's vehicle fleet.     

Cigarette smoking,illicit drug use and the value of life

This article investigates the relationship between cigarette smoking and illicit drug use and compensating wage differentials for the risk of job-related death. Knowledge of an individual's experiences with cigarettes and illicit drugs is used to identify worker heterogeneity in job-risk preferences. The results show that individuals who are both nonsmokers and nondrug users work in the safest jobs and receive the highest compensating wage differentials for job-related risk. Significant differences in job risk and compensating differentials are also found between smokers and nonsmokers and drug users and nondrug users. Estimates of the statistical value of life increase from $2.9 million to $7.1 million when moving from the full sample of workers to those individuals classified as nonsmokers and non-drug users.