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.     

Valuation of Multiple Environmental Programs

We examined sequence effects on willingness-to-pay (WTP) when people evaluate a series of environmental goods. Each respondent evaluated five different environmental goods using WTP and four evaluative attitude ratings. There was a strong sequence effect: WTP was much larger for the first good than for goods evaluated afterward. Also, total WTP for the bundle of five goods depended on which good was evaluated first: the more highly valued the first good, the higher the total WTP for the bundle. The attitude ratings are shown to be more statistically efficient than WTP in measuring the relative importance of different environmental goods.     

On the Contingent Valuation of Safety and the Safety of Contingent Valuation: Part 1-Caveat Investigator

This article reports the results of two studies aimed at testing and refining a procedure for estimating willingness-to-pay based monetary values of safety using the contingent valuation method. In spite of the fact that respondents were given the opportunity to discuss various safety issues and key concepts in focus group meetings held in advance of individual interviews, and were also given ample opportunity to revise their responses in the light of the overall pattern of these responses, the results show clear evidence of extensive and persistent insensitivity to the scale and scope of the safety improvements that were specified in the contingent valuation questions, as well as vulnerability to framing effects. This clearly casts serious doubt on the reliability and validity of willingness-to-pay based monetary values of safety estimated using conventional contingent valuation procedures.     

Willingness to Pay for Health Protection: Inadequate Sensitivity to Probability?

Efficient investments in health protection require valid estimates of the public's willingness to forgo consumption for diminished probabilities of death, injury, and disease. Stated valuations of risk reduction are not valid measures of economic preference if the valuations are insensitive to probability variation. This article reviews the existing literature on CV studies of reductions in health risk and finds that most studies are poorly designed to assess the sensitivity of stated valuations to changes in risk magnitude. Replication of a recent study published in this journal by Johannesson et al. (1997) demonstrates how serious the problem of insensitivity can be, even for a study that reports plausible results. New empirical results are presented from telephone surveys designed to provide internal and external tests of how WTP responds to size of risk reduction. The effect of variations in instrument design on estimated sensitivity to magnitude is examined. Overall, estimated WTP for risk reduction is inadequately sensitive to the difference in probability, that is, the magnitude of the difference in WTP for different reductions in risk is typically smaller than suggested by standard economic theory. Additional research to improve methods for communicating changes in risk is needed, and future studies of stated WTP to reduce risk should include rigorous validity checks.     

Public Perceptions of Risk and Preference-Based Values of Safety

This article reports the results of two studies aimed at estimating preference-based values of safety in three contexts—namely rail, domestic fires and fires in public places—relative to the corresponding value for roads using matching (or equivalence) questions. In addition, both studies included a variety of questions intended to shed light on respondents' perceptions of risk and attitudes to safety in the various contexts. While the two studies were, to all intents and purposes, identical in the procedure that they employed, the essential difference between them was that the first study took place in late 1998, whereas the second study was carried out in early 2000 in the aftermath of a major rail accident at Ladbroke Grove near London's Paddington station which occurred in October 1999 and in which 29 passengers and 2 train drivers died. In addition, the second study sample was deliberately weighted to contain an above-average proportion of regular rail users. These studies demonstrated how certain factors which have been shown to affect people's perception of risk (see Slovic, P. (1992). In S. Krimsky and D. Golding (eds.), Social Theories of Risk, Westport, CT: Praeger, pp. 117–152) also affected our respondents' priorities over safety programs. The results also showed however, that the impact of these perceptions upon the trade-offs between preventing deaths in different hazard contexts was a good deal less pronounced than has been suggested by the value differentials that are currently implicit—and in some cases, explicit—in public policy making.     

An Experimental Investigation of the Disparity Between WTA and WTP for Lotteries

In this paper we experimentally investigate the disparity between willingness-to-accept (WTA) and willingness-to-pay (WTP) for risky lotteries. The direction of the income effect is reversed by endowing subjects with the highest price of a lottery when asking the WTP question. Our results show that the income effect is too small to be the only source of the disparity. Since the disparity concentrates on a subsample of subjects, parametric and nonparametric tests of the WTA-WTP ratio may lead to contradictory results. The disparity is significantly reduced when background risk is introduced. That is, putting subjects always into a risky position could improve the contingent valuation method, which is often concerned with the assessment of risky situations such as health risks, automobile safety, etc.      

Subjective probabilities and utility with event-dependent preferences

This article generalizes Savage's theory to include event-dependent preferences. The state space is partitioned into finitely many events. The induced preferences over consequences are assumed independent of the underlying states within, but not across, these events. This results in an additively separable representation of preferences over acts. The dependence of the preference relation over consequences on the events is represented by event-dependent mappings of the set of consequences onto itself. Given these mappings, the preferences on acts are represented by the expectation of event-dependent utilities on the consequences with respect to unique subjective probabilities on the states.Helpful discussions with David Schmeidler are gratefully acknowledged.     

Social Willingness to Pay,Mortality Risks and Contingent Valuation

The Willingness-to-Pay approach is the basic justification for the use of the Contingent Valuation method to evaluate public mortality risk reduction programs. However, aggregating unweighted willingness-to-pay is a valid method only when individuals have the same marginal value of money, an unrealistic assumption in the presence of heterogeneity. We show that heterogeneity on wealth and baseline risk (respectively on risk reduction) leads to systematically overestimate (respectively underestimate) the social value of a risk reduction program. Using a recently published Contingent Valuation analysis, we find this overestimation to be quite modest though, approximately 15% in an upper bound case.     

On the Contingent Valuation of Safety and the Safety of Contingent Valuation: Part 2 - The CV/SG "Chained" Approach

This article reports the results of a study aimed at estimating a willingness-to-pay based value of statistical life for road risks using a multi-stage approach which involves "chaining together" responses to contingent valuation and standard gamble questions.The rationale for employing a multi-stage approach is to break the wealth/risk of death trade-off down into a number of conceptually manageable steps, thereby trying to attenuate the various biases that appear to be pervasive in responses to more direct contingent valuation questions in the health and safety field.     

Willingness to Pay for Rehabilitation Versus Punishment to Reduce Adult and Juvenile Crime

Punitive penal policies are often justified on the assumption that members of the public demand punitive responses to crime. The current study employed a contingent valuation survey design to assess the extent to which this is true in the state of New South Wales, Australia. The survey investigated public willingness to pursue crime control policies that rehabilitate offenders versus those that punish. Using a quota‐based telephone survey, 1885 taxpaying residents in the state of New South Wales, Australia, were asked how much additional tax they would be willing to pay to produce a 10 per cent reduction in serious crime. A 2times2 randomised factorial design was employed, with one factor being the means offered to reduce crime (rehabilitation versus imprisonment) and the other factor being the population under study (adults versus juveniles). There were no significant differences in willingness to pay for crime reduction across any of the four resulting groups. The findings suggest that the NSW public are equally disposed to reducing crime by rehabilitating offenders as they are to imprisoning them for longer. There would therefore seem every reason to pursue rehabilitation with greater vigour, especially in light of the relative cost‐effectiveness of rehabilitation programs over incarceration.     

To be,or not to be,that is the question: An empirical study of the WTP for an increased life expectancy at an advanced age

This study reports an attempt to measure the value of an increased survival probability at advanced ages. It turns out that the average willingness to pay for a program which would increase the expected length of life by one year, conditional on having survived to the age of 75 years, is lower than $1,500. The willingness to pay increases with a person's age, but at a low and seemingly constant rate (1–4 percent per year).     

Preference reversals and the measurement of environmental values

Numerous studies have demonstrated that theoretically equivalent measures of preference, such as choices and prices, can lead to systematically different preference orderings, known as preference reversals. Two major causes of preference reversals are the compatibility effect and the prominence effect. The present studies demonstrate that the combined effects of prominence and compatibility lead to predictable preference reversals in settings where improvements in air quality are compared with improvements in consumer commodities by two methods-willingness to pay for each improvement and choice (For which of the two improvements would you pay more? Which improvement is more valuable to you?). Willingness to pay leads to relatively greater preference for improved commodities; choice leads to relatively greater preference for improved air quality. These results extend the domain of preference reversals and pose a challenge to traditional theories of preference. At the applied level, these findings indicate the need to develop new methods for valuing environmental resources.     

Calibrating Hypothetical Willingness to Pay Responses

Experimental data comparing hypothetical and real dichotomous choice responses for two different goods were used to estimate a statistical bias function to calibrate the hypothetical yes responses. The probability that a hypothetical yes response would be a real yes response was estimated as a function of the individual's self-assessed certainty of the hypothetical yes response (assessed on a 0–10 scale) and a variable representing the price level. Without calibration the hypothetical yes responses significantly exceeded the proportion of real yes responses, but after calibration the null hypothesis of no difference between hypothetical and real responses could not be rejected in any of the experiments.     

The value of mortality risk reductions in Delhi,India

We interviewed commuters in Delhi, India, to estimate their willingness to pay (WTP) to reduce their risk of dying in road traffic accidents in three scenarios that mirror the circumstances under which traffic fatalities occur in Delhi. The WTP responses are internally valid: WTP increases with the size of the risk reduction, income, and exposure to road traffic risks, as measured by length of commute and whether the respondent drives a motorcycle. As a result, the value of a statistical life (VSL) varies across groups of beneficiaries. For the most highly-exposed individuals the VSL is about 150,000 Purchasing Power Parity (PPP) dollars.

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.     

The Value of a Statistical Life in Transport: Findings from a New Contingent Valuation Study in Sweden

This article presents the results of a contingent valuation study from Sweden aimed at estimating the value of a statistical life (VOSL) in road traffic safety. Data on respondents' own subjective risk was collected by use of visual aids presented in a mail questionnaire. The relationship between willingness-to-pay (WTP) and absolute risk reduction was estimated by using a non-linear, least absolute deviation estimation method. This study generated an income-adjusted VOSL of SEK22.3 million (US$2.6 million). Analysis of WTP's sensitivity to probability variation indicates that in future studies, valuing risk reductions in road traffic, the magnitude of absolute risk and relative risk reductions to consider should be in perceptible range. On addition it should also be possible for respondents to compare the magnitudes of different risk reductions.     

Valuing International Safety Externalities: Does the “Golden Rule” Apply?

Journal of Risk and Uncertainty - How should a developed country quantify the costs and benefits of the safety externalities that its energy and environmental policies generate for a developing...     

Effects of Disease Type and Latency on the Value of Mortality Risk

We evaluate the effects of disease type and latency on willingness to pay (WTP) to reduce environmental risks of chronic, degenerative disease. Using contingent-valuation data collected from approximately 1,200 respondents in Taiwan, we find that WTP declines with latency between exposure to environmental contaminants and manifestation of any resulting disease, at a 1.5 percent annual rate for a 20 year latency period. WTP to reduce the risk of cancer is estimated to be about one-third larger than WTP to reduce risk of a similar chronic, degenerative disease. The value of risk reduction also depends on the affected organ, environmental pathway, or payment mechanism: estimated WTP to reduce the risk of lung disease due to industrial air pollution is twice as large as WTP to reduce the risk of liver disease due to contaminated drinking water.     

Socioeconomic status and the dynamics of preferences for income inequality in the United States, 1978–2016

Although considerable evidence indicates that public preferences for income inequality and redistribution vary across socioeconomic groups (i.e., occupation and income), much less is known about the temporal dynamics of these preferences. The purpose of this study is (a) to examine whether the attitudinal distance between managerial/professional workers and unskilled manual workers has changed (converged or diverged) over time and to (b) explore the reasons for and implications of the dynamics of preferences in the past several decades. Using data from the General Social Survey 1978–2016 (23 time‐points; N = 27,211), this study finds that the influence of occupational class has lost some of its significance in shaping public preferences for income inequality and that the declining effect of occupation can be explained in part by the attitudinal convergence between better‐ and less‐educated citizens. Findings suggest that proequality coalitions across educational boundaries play a remedial role in bridging the occupational divide over government redistribution in the United States.