Treating respondent uncertainty in contingent valuation: A comparison of empirical treatments

This research examines the impact of uncertainty on contingent valuation responses using (1) a survey of Canadian landowners about willingness to accept compensation for converting cropland to forestry and (2) a survey of Swedish residents about willingness to pay for forest conservation. Five approaches from the literature for incorporating respondent uncertainty are used and compared to the traditional random utility model with assumed certainty. The results indicate that incorporating uncertainty has the potential to increase fit, but could introduce additional variance. While some methods for uncertainty can be an improvement over traditional approaches, it is imperative to exercise caution when making systematic judgments about the effect of uncertainty on contingent valuation responses.     

Marginal Valuation of Charismatic Species: Implications for Conservation

Most contingent valuation studies focus on total willingness to pay (WTP) as a measure of welfare change. For policy involving species preservation, however, it is important to distinguish between the benefits of preventing a species from going extinct and the benefits of preserving numbers above the minimum viable population (MVP) level. Once MVP is exceeded, marginal WTP becomes relevant. These propositions are illustrated for the case of one charismatic species whose management is much debated, minke whales in the Northeast Atlantic Ocean. It is shown that, for a given estimate of total preservation value, strict conservation and extinction can both be optimal. This finding highlights the importance of collecting marginal values in contingent valuation surveys.     

Local Perception of Public Goods: Recent Assessments of Willingness-to-pay for Endangered Species

A contingent valuation mail survey was administered in late 2001 to better understand current public opinion about controversial endangered species preservation in Orange County, California. Questionnaire design focused on additional taxes residents would be willing to pay to support recovery plans. Habitat and recovery of a single species, the Riverside fairy shrimp, is valued at around $25 per household, and the valuation is significantly changed by the higher scope of the public good provided, with an annual willingness-to-pay of around $50–60 per household for all local endangered species. Across the whole county, the public valuation of biodiversity is substantial yet probably could not fund necessary land acquisition for critical habitat, so continued national support for species preservation remains logical. (JEL Q51 , Q57 , Q58 )     

Contingent values as implicit contracts: estimating minimum legal willingness to pay for conservation of large carnivores in Sweden

Mean willingness-to-pay (WTP) based on multiple bounded, discrete choice responses from contingent valuation surveys are normally obtained using some kind of parametric estimator. This paper instead exploits the possibility to interpret the response to the discrete-choice question as an implicit contract between the researcher and the respondent, resulting in a minimum legal WTP (MLW) estimator. Never previously used in valuation literature, it is used in this paper to estimate the WTP for the preservation of large carnivores in Sweden, based on a large scale, national survey. Results show that MLW estimates only were 12–19% of the comparable parametric estimates. In keeping with other results in contingent valuation literature, we find that the MLW estimates are positively related to the educational level, income and the fraction of urban population, while negatively related to age. Among the advantages of the MLW estimator is its transparency as well as the fact that it rests on a contractual notion of WTP.      

Comparing benefit estimates from travel cost and contingent valuation using confidence intervals for Hicksian welfare measures

An approach to determining whether benefit estimates derived from the travel cost method and contingent valuation method are statistically different is presented. Unlike past comparisons compensating variation is estimated for both methods. Benefit comparisons are made more rigorous by use of confidence intervals which are developed using the same Krinsky and Robb simulation technique for both valution mothods. The techniques are applied to deer hunting in California. While point estimates of benefits from both truncated and untruncated adjusted travel cost methods are lower than the contingent valuation method, the confidence intervals on the untruncated travel cost method do overlap the contingent valution method benefit estimates.     

The Endowment Effect and Expected Utility

The endowment effect, which is well documented in the contingent valuation literature, alters people's preferences according to a reference point established in an elicitation question. In particular, the utility that people place on a bundle is both a positive function of the quantities of the goods comprising the bundle, and a negative function of any loss (real or hypothetical) that the elicitation question asks them to incur. Biases such as this have lead some to reject the contingent valuation method as a means of quantifying costs and benefits in favour of other methods of preference elicitation such as standard gambles. But, most preference elicitation methods used by economists require people to express their preferences for one good in terms of their willingness to forego some of another good. Consequently, it is reasonable to expect that, and prudent to check whether, an endowment effect is also evident in other methods of preference elicitation such as von Neumann-Morgenstern's standard gambles. Internal inconsistencies in the standard gamble method from the experimental economics literature and from a study into the value of non-fatal road injuries are shown to be evidence that an endowment effect is also at work in standard gambles.     

Problems in valuing the benefits of biodiversity protection

This paper considers two problems in valuing the benefits of biodiversity protection. These are, firstly, that preferences for biodiversity protection may be lexicographic rather than utilitarian. The more individuals for whom this is true, the less is cost-benefit analysis validated as a means of decision making for biodiversity protection, since lexicographic preferences are incompatible with the Kaldor-Hicks Compensation Test. Secondly, people may be poorly informed about the meaning of biodiversity, complicating the use of contingent valuation as a means of measuring preservation benefits. This paper first discusses the meaning of biodiversity, and trends in diversity over time. We offer some empirical evidence with regard to lexicographic preferences; consider the implications of having poorly-informed consumers; and then report the results of a contingent valuation study of biodiversity protection with varying levels of information. We find that willingness to pay for biodiversity protection increases with the level of information provided.We thank David Pearce, participants at a seminar at University College London, and two referees for comments on earlier versions of this paper.     

Valuing water level changes in reservoirs using two stated preference approaches: An exploration of validity

The combination of travel cost (TCM) and contingent behaviour (CB) methods is a relatively new research avenue in the recreational valuation community. Contrary to simple TCM applications, TCM-CB facilitates the ex ante valuation of marginal welfare effects resulting from environmental quality or quantity changes, similar to the contingent valuation method (CV). Even though TCM-CB is highly policy relevant, i.e. to inform changes in management regimes at recreational sites, the validity of estimates has hardly received any attention and little is known about the performance of TCM-CB compared to CV. In this paper, TCM-CB and CV are explored with respect to several validity tests in a case study on the recreational effects of water level changes in a reservoir. Overall, the findings reveal that TCM-CB and CV perform equally well in terms of theoretical validity, but that the marginal recreational value varies significantly between the two methods. We also observe that both methods face similar internal difficulties with respect to the stability of values when the order of a set of valuation questions is changed.     

Existence Value and the Contingent Valuation Method

People express concern about the possible extinction of animal species which they will never see, about damage to wilderness areas they will never visit, and so on. Such concerns are often interpreted by economists in terms of 'existence' or 'passive use' values. Three views have been proposed regarding the appropriate way of dealing with existence values in benefit-cost analysis. First, the existence values and concerns about environmental preservation that are not related to use may be disregarded. Second, concerns about environmental preservation may be taken into account, but not interpreted as existence values or evaluated in monetary terms. Third, the benefit-cost analysis may be modified to incorporate monetary estimates of existence values. Advocates of the third approach have developed a range of techniques for eliciting existence values, collectively referred to as the contingent valuation method. In this paper, the concept of existence value and the techniques of contingent valuation are surveyed, with the aim or providing a basis for comparisons of the three approaches described above.     

Measuring Passive Use Value: Pledges, Donations and CV Responses in Connection with an Important Natural Resource

This paper examines monetary valuations of lost passive-use benefits associated with damage to a unique environmental resource – a national park, elicited through contingent valuation, and compares them with actual donations to the same end, where the latter are interpreted as a quasi-market expression of willingness to pay for non-market resource services. The relationships between the two valuation approaches were investigated in the specific context of an environmental episode which damaged a unique natural endowment, Israel's Carmel National Park. The empirical analysis is based on data from two sample surveys; one sample was drawn from the population of people who either pledged or pledged and donated during a fund-raising campaign following the episode, with the proceeds dedicated to rehabilitation or prevention of future episodes; the second sample was drawn from the general population of the country. The results cannot be interpreted as providing unqualified support for the reliability of contingent valuation as a means for obtaining passive use values.     

The recreational value of coral reefs: A meta-analysis

Coral reefs are highly productive ecosystems that provide a variety of valuable goods and services, including recreational opportunities. The open-access nature and public good characteristics of coral reefs often result in them being undervalued in decision making related to their use and conservation. In response to this, there now exists a substantial economic valuation literature on coral reefs. For the purposes of conducting a meta-analysis of this literature, we collected 166 coral reef valuation studies, 52 of which provided sufficient information for a statistical meta-analysis, yielding 100 separate value observations in total. Focusing on recreational values, we use US$ per visit as the dependent variable in our meta-analysis. The meta-regression results reveal a number of important factors in explaining variation in coral reef recreational values, notably the area of dive sites and the number of visitors. Different valuation methods are shown to produce widely different values, with the contingent valuation method producing significantly lower value estimates. Using a multi-level modelling approach we also control for authorship effects, which proves to be highly significant in explaining variation in value estimates. We assess the prospects for using this analysis for out-of-sample value transfer, and find average transfer errors of 186%. We conclude that there is a need for further high-quality valuation research on coral reefs.     

Economic Value of Water Quality Improvement by One Grade Level in Erhai Lake: A Willingness-to-Pay Survey and a Benefit-Transfer Study

Water quality in China has seriously deteriorated in recent years. However, very few valuation studies have been conducted to estimate the monetary values associated with water quality changes. As a result, the decision makers can hardly make rational choices with regard to investments in water quality improvement. This paper presents a valuation study conducted in Dali, Yunnan Province, which aims to estimate the total economic value of improving the water quality of Erhai Lake by one grade level. Both the contingent valuation method and the benefit transfer approach are employed in this study. The contingent valuation estimation strategy reveals that, on average, a household located in Dali is willing to pay about 27 yuan per month continuously for 5 years for the water quality improvement, equivalent to 1.7% of the household monthly income. The elasticity of willingness-to-pay with respect to income is estimated to be 0.28. The internal rate of economic return of the proposed pollution control project is estimated to be 13%. The benefit transfer exercise produces a similar estimation on willingness to pay (WTP) values, with a difference of less than 2% compared with the contingent valuation approach. The results indicate the potential reliability of using the benefit transfer approach for valuation estimations in Chinese provinces.     

Motives behind willingness to pay for improving biodiversity in a water ecosystem: Economics, ethics and social psychology

This paper reports on empirical work extending the standard economic approach to valuation by including psychological and philosophical factors. More specifically a contingent valuation method survey was applied to biodiversity improvement while simultaneously assessing rights based beliefs, consequentialism and the theory of planned behaviour. The latter was assessed using measures of attitudes, subjective norms and perceptions of control over willingness to pay. The results show that standard socio-economic explanatory variables are far inferior to those of social psychology and philosophy, and that these factors offer a better understanding of the motives behind responses to contingent valuation. The implication is that alternative means of measuring an individual's pluralistic values should be taken into account in order to assess the validity and meaning of willingness to pay.     

Scale-perception bias in the valuation of environmental risks

The valuation of environmental risks is commonly approached with the utilization of stated preference methods such as contingent valuation. In these methods, money is utilized as the scale that reflects the individual's underlying utility function. However, this scale can vary across individuals due to different perceptions on what are the right or appropriate bounds for Willingness To Pay (WTP). In this article, we test for scale-perception bias and propose a correction method based on the utilization of anchoring vignettes that define different degrees of preference for the nonmarket good. The proposed method is applied to study the commonly found anomaly ‘probability neglect’, which is defined by the insensitivity to the probability levels in the valuation of environmental risks. The results show that probability neglect disappears when WTP responses are corrected for self-perception bias through the utilization of the anchoring vignettes approach.     

Economic valuation of species loss in the open sea

Although the oceans cover 70% of the surface of the planet few studies have considered the economic valuation of marine biodiversity, despite the importance of such information for marine management and conservation. This study uses a contingent valuation method to estimate the public's willingness to pay (WTP) to avoid loss in the number of marine species in the waters around the Azores archipelago. We estimated the marginal value associated with increased levels of species loss (10% and 25%) in five marine taxa (mammals, fish, algae, birds and invertebrates) and all marine species considered as a whole, via a face to face survey of residents and visitors to two Azorean islands. The results suggest small but statistically significant differences in the WTP to prevent losses in the different taxa (mammals = fish > birds = invertebrates = algae). The results also suggest a greater WTP to preserve all marine taxa as a whole, than for a series of individual marine taxa. The valuation of the ecosystem and taxa may be influenced by the maritime culture of the respondents, but despite this, the findings challenge the commonly held premise that charismatic taxa have a disproportionately strong influence on WTP, and they provide important insights into human preferences for biodiversity conservation.     

Joint estimation of contingent valuation survey responses

Hanemann's utility difference model for the dichotomous choice contingent valuation method is modified to account for interrelationships between responses to a set of contingent valuation questions. A nonlinear seemingly unrelated regression model is presented to jointly estimate the probit models and to derive WTP from the CV responses. The model is used to test and impose restrictions derived from economic theory on the utility difference model. Mean WTP estimates for three different types of changes in the quality of California deer hunting were uniformly lower for the joint response probit model compared to a set of independent probit models.     

Altruistic,egoistic and biospheric values in willingness to pay (WTP) for wildlife

We attempt to measure general attitudes and ethical beliefs towards preservation, as well as the importance of each of the three considered value orientations (biospheric, egoistic and altruistic) in WTP estimates. In the present study, we apply the GAC scale to a contingent valuation exercise for the recovery of the common murre (Uria aalge) in Galicia (Spain). Up to now, only a few studies in the field of environmental and ecological economics have analyzed value orientations under the Environmental Concern (EC) framework, obtaining mixed results. In the present work, we conclude that ethical aspects affect the individuals decision making process, and that value orientations play an important role in the pro-environmental attitude formation. These value orientations affect willingness to pay (WTP) estimates for environmental goods.     

Altruistic, egoistic and biospheric values in willingness to pay (WTP) for wildlife

We attempt to measure general attitudes and ethical beliefs towards preservation, as well as the importance of each of the three considered value orientations (biospheric, egoistic and altruistic) in WTP estimates. In the present study, we apply the GAC scale to a contingent valuation exercise for the recovery of the common murre (Uria aalge) in Galicia (Spain). Up to now, only a few studies in the field of environmental and ecological economics have analyzed value orientations under the Environmental Concern (EC) framework, obtaining mixed results. In the present work, we conclude that ethical aspects affect the individuals decision making process, and that value orientations play an important role in the pro-environmental attitude formation. These value orientations affect willingness to pay (WTP) estimates for environmental goods.     

Differentiating use and nonuse values for coastal pond water quality improvements

This paper measures the benefits of water quality improvements in three coastal ponds on the island of Martha's Vineyard, Massachusetts, U.S.A. Use, option, and existence values were elicited from Martha's Vineyard property owners by the contingent valuation method. On average, more than half of the total benefits are attributed to existence value. Results from the Heckman selection model show that the exclusion of protest, as well as missing bids, does not cause significant bias in estimating respondents' willingness-to-pay. Socioeconomic characteristics are found to have distinctively different influences on use, option, and existence values. Different model parameters are likely to be estimated depending on which value categories are measured by a selected valuation technique. These findings emphasize the importance of nonuse values from water quality improvements and of socioeconomic characteristics for measuring different categories of values.Associate Scientist, the Marine Policy Center, Woods Hole Oceanographic Institution. Support for this research was provided by the Pew Charitable Trust, and the Marine Policy Center. Thanks are due Elliot Backerman for making the data available to the author, and Peter Britz and Sarah Repetto for research assistance. Comments and suggestions on an earlier draft of this paper from Steven Edwards, A. Myrick Freeman, Porter Hoagland, Raymond Kopp, V. Kerry Smith and two anonymous reviewers are gratefully acknowledged. This article is WHOI Contribution No. 7752.     

海岸带地区环境资源经济价值的评估方法及实证分析

以大连市金石滩国家海洋公园为例,利用条件价值法,通过建立双边界二分式Logit模型,分别计算了居民和游客对改善和保护海岸带三种最重要环境资源(海水、沙滩、生物种群)的平均意愿支付,进而评估了金石滩国家海洋公园海岸带游憩资源的经济价值。结果显示:金石滩国家海洋公园的海水、沙滩和生物种群的经济价值分别为4.30亿元、3.92亿元和3.57亿元。最后指出:将这些信息纳入海岸带地区的综合管理成本效益分析,对于实现海岸带资源的可持续发展有重要意义。