Better than their reputation: enhancing the validity of contingent valuation mail survey results through citizen expert groups

Although contingent valuation is the dominant technique for the valuation of public projects, especially in the environmental sector, the high costs of contingent valuation surveys prevent the use of this method for the assessment of relatively small projects. The reason for this cost problem is that typically only contingent valuation studies which are based on face-to-face interviews are accepted as leading to valid results. Particularly in countries with high wages, face-to-face surveys are extremely costly considering that for a valid contingent valuation study a minimum of 1000 completed face-to-face interviews is required. This paper tries a rehabilitation of mail surveys as low-budget substitutes for costly face-to-face surveys. Based on an empirical contingent valuation study in Northern Thailand, it is shown that the validity of mail surveys can be improved significantly if so-called Citizen Expert Groups are employed for a thorough survey design.     

Scope insensitivity in contingent valuation of complex environmental amenities

It has been argued that respondents in contingent valuation (CV) surveys, asked to value complex environmental amenities, will state willingness to pay (WTP) independently of the scope of the project. Such insensitivity to scope would be at odds with rational choice, and could therefore imply that CV is not a theoretically valid method for biodiversity valuation. The scope test in the present CV study was applied to endangered species preservation. Respondents were split in four sub-samples facing different scopes of endangered species preservation. The design allowed for both external and internal scope tests. Furthermore, the tests were split according to elicitation format. Of four external tests of insensitivity to scope, one was rejected, two gave mixed results, depending on either the type of test or elicitation format, and for the last one the null hypothesis could not be rejected. Of five internal tests, insensitivity to scope was rejected in three cases, one test gave mixed results, and one could not be rejected. Survey design features of the CV study, especially an unfamiliar sub-group of endangered species, could explain the apparent insensitivity to scope observed.     

A comparison of alternative contingent valuation elicitation treatments for the evaluation of complex environmental policy

Attempts to evaluate the economic benefits associated with complex environmental policies, using the contingent valuation (CV) method, have been dogged by controversy. In particular, debate has centred on the influence of embedding and related effects on the validity of CV willingness-to-pay (WTP) estimates. This paper discusses these effects in the context of identifying the most appropriate WTP elicitation treatment to evaluate the willingness to pay for the various elements of a multi-dimensional environmental policy. The findings of an empirical experiment demonstrate that a top-down allocation treatment, which uses independent sub-samples for individual policy components, provides the most reliable treatment to value all aspects of a multi-dimensional policy, whilst also overcoming embedding bias problems.     

The value of urban open space: Meta-analyses of contingent valuation and hedonic pricing results

Urban open space provides a number of valuable services to urban populations, including recreational opportunities, aesthetic enjoyment, environmental functions, and may also be associated with existence values. In separate meta-analyses of the contingent valuation (CV) and hedonic pricing (HP) literature we examine which physical, socio-economic, and study characteristics determine the value of open space. The dependent variable in the CV meta-regression is defined as the value of open space per hectare per year in 2003 US$, and in the HP model as the percentage change in house price for a 10 m decrease in distance to open space. Using a multi-level modelling approach we find in both the CV and HP analyses that there is a positive and significant relationship between the value of urban open space and population density, indicating that scarcity and crowdedness matter, and that the value of open space does not vary significantly with income. Further, urban parks are more highly valued than other types of urban open space (forests, agricultural and undeveloped land) and methodological differences in study design have a large influence on estimated values from both CV and HP. We also find important regional differences in preferences for urban open space, which suggests that the potential for transferring estimated values between regions is likely to be limited.     

Correcting for non-response bias in contingent valuation surveys concerning environmental non-market goods: an empirical investigation using an online panel

Data collection for economic valuation by using Internet surveys and pre-recruited Internet panels can be associated with severe disadvantages. Problems concerning sample coverage and sample representativeness can be expected. Representation errors may occur since people can choose whether to be part of an Internet panel and subsequently whether they wish to participate in the survey, thereby introducing two elements of potential self-selection. These elements may be correlated with preferences, thus making the respondents a non-random and non-representative sample, ultimately biasing results. This paper analyses a sample used for an Internet contingent valuation method survey eliciting preferences for improvements in water quality of a river. We find that some variables that affect the survey participation decision also affect willingness-to-pay, consequently biasing our welfare estimates. We show how adjusting willingness-to-pay for this bias can be accomplished by using a grouped data model incorporating a correlation parameter to account for selection.     

Exploring Values,Context and Perceptions in Contingent Valuation Studies: The CV Market Stall Technique and Willingness to Pay for Wildlife Conservation

Public preferences for conservation and environmental management may be identified in willingness to pay (WTP) studies. Normally part of a contingent valuation exercise, WTP studies elicit monetary estimates of non-market economic goods. This paper describes a new approach to WTP, the CV Market Stall, a technique that adds a discursive, qualitative dimension to contingent valuation. It is suggested that the CV Market Stall technique is a good method for exploring attitudes and responses to environmental project proposals. The flexible format, with an emphasis upon information provision, discussion and learning would also allow contingent valuation to be extended to much more complex and uncertain environmental issues.     

Scope effects of respondent uncertainty in contingent valuation: evidence from motorized emission reductions in the city of Nairobi,Kenya

This study analyzed the scope effects of respondent uncertainty in contingent valuation (CV) by evaluating whether willingness to pay (WTP) estimates were sensitive to changes in the magnitudes of motorized emission reductions in the city of Nairobi, Kenya. The WTP estimates were elicited through the conventional payment card (PC), stochastic payment card (SPC) and the polychotomous payment card (PPC) formats. While SPC and PPC formats were used to capture respondent uncertainty, the PC format captured respondent certainty regarding the amounts individuals were WTP for emission reductions. Based on parametric and nonparametric analysis, results show that certain (PC) respondents stated significantly larger WTP amounts for larger emission reductions than for smaller reductions. Conversely, uncertain (SPC and PPC) respondents stated smaller amounts for larger emission reductions than certain (PC) respondents. The implication is that though respondents were sensitive to the scope of motorized emission reductions, respondent uncertainty lowered their sensitivity to scope.     

On the value of large predators in Sweden: a regional stratified contingent valuation analysis

This paper contributes with an applied policy analysis of the predator preservation policy in Sweden. We estimate the overall mean willingness to pay (WTP) for preserving the four large predators in the Swedish fauna by applying the contingent valuation method. Using survey data from 2004 we find that 50 percent of the Swedish population is willing to contribute financially toward implementation of the predator policy package, and that the estimated overall mean WTP is approximately SEK 290. Further, we test for spatial differences in attitudes and WTP and find that respondents in Stockholm have the highest overall mean WTP, while respondents living in wolf-territories have the lowest. Our mean WTP measure is flawed with upward bias, since we cannot estimate the willingness to accept for those with clearly negative preferences regarding the predator policy package (e.g. hunters). In this paper, we set their WTP equal to zero. Thus, we cannot rule out the possibility that the mean willingness to pay is, in fact, negative, i.e. the social-value of implementing the predator policy is negative. Finally, the estimates of the overall WTP are sensitive to response-uncertainty. When the respondents indicate uncertainty about their valuation, they tend to state higher values.     

What Level of Information Enables the Public to Act Like Experts When Evaluating Ecological Goods?

Although contingent valuation is widely discussed in the literature as a technique for environmental valuation, it is well recognized that a number of problems are associated with its use. This paper seeks to address two of these problems: the difficulty of externally verifying the results of a CV study; and the choice of an appropriate level of information to provide to respondents. Four sites were evaluated, first by expert ecologists and then by the general public using the CV method. In conducting the CV, six different categories of information were presented to different groups of respondents to test which was most appropriate.The results show that, given an information set consisting of photographic,textual and ecological data, respondents to a CV study were able to rank the four sites in the same order as ecological experts. This may be seen as a form of external verification to the results of the contingent valuation.     

Lexicographic preference in biodiversity valuation: Tests of inconsistencies and willingness to pay

Previous contingent valuation (CV) studies on biodiversity have indicated that as much as one-quarter of the respondents show lexicographic preferences when facing biodiversity-money trade-offs. This behaviour is incompatible with welfare theory underlying CV, and thus questions the validity and reliability of the outcome of CV of changes in biodiversity. However, it is difficult from CV responses to distinguish between strict and modified lexicographic preferences, and those attaching a high value to biodiversity. This paper adds to the empirical evidence showing that what at first hand seems to represent strict lexicographic preferences is at most representing modified lexicographic preferences, and probably rather represent just high valuation of biodiversity. Data on both hypothetical and actual willingness to pay (WTP) from a CV study on biodiversity were used to perform tests of inconsistent attitudes to estimate the maximum share of non-compensatory preferences for biodiversity. The results show that there are very few respondents in the group that consistently state high preference for biodiversity preservation and show clear reluctance to trade-off biodiversity with other goods. However, this group also had higher WTP, both hypothetical and actual, than the reference group. This is consistent with exchange preferences and steep indifference curves. Thus, people with lexicographic preferences for biodiversity are probably less numerous than previously indicated.     

Household Willingness to Pay and Farmers' Willingness to Accept Compensation for Establishing a Recreational Woodland

The UK Forestry Commission's recently implemented Community Woodland scheme sets out to provide new recreational woodland facilities near to towns and cities where such resources are in short supply. This study examines household willingness to pay (WTP) for such a proposed woodland by means of the contingent valuation (CV) method. A stratified sample of 325 households in Wantage, Oxfordshire, was interviewed and asked to state both their annual and per-visit WTP. Analysis of a number of recognized potential biases suggested that the results obtained must be treated with caution although we argue that the CV provides a useful ballpark indication of preferences. A simultaneous CV survey of farmers' willingness to accept compensation for converting agricultural land into woodland proved to be far more robust, despite a small sample size. We conclude that farmers are more familiar with the concept of assessing potential compensation than are households with estimating hypothetical payments for increased provision of public goods.     

Considering Conservation Value in Economic Appraisals of Coastal Resources

Measuring the economic value of environmental quality is useful to evaluate policies that affect the use of natural resources. This paper presents the findings of a contingent valuation (CV) survey designed to measure non-use values for the natural coastal environment.This was attempted through evaluating public and scientific values of conservation quality. The results suggest that public perceptions of conservation quality are multidimensional,and that it may be difficult for some individuals to express their preferences for the conservation value of natural resources in monetary terms. Additionally, public and scientific judgments differ concerning some of the physical attributes imparting conservation value. These findings have important implications on efforts to consider environmental quality in land and coastal use decisions.     

Willingness to pay for safe drinking water: Evidence from Parral, Mexico

A referendum-format contingent valuation (CV) survey is used to elicit household willingness to pay responses for safe and reliable drinking water in Parral, Mexico. Households currently adopt a variety of averting and private investment choices (e.g., bottled water consumption, home-based water treatment, and installation of water storage facilities) to adapt to the existing water supply system. These revealed behaviors indicate the latent demand for safer and more reliable water services, which is corroborated by the CV survey evidence. Validity findings include significant scope sensitivity in WTP for water services. Further, results indicate that households are willing to pay from 1.8% to 7.55% of reported household income above their current water bill for safe and reliable drinking water services, depending upon the assumptions about response uncertainty.     

A new recoding method for treating protest responses in contingent valuation studies using travel cost data

In this paper, it is proposed one method to recode protest responses applicable to the simple dichotomous format valuation question made to visitors to natural environment in contingent valuation studies. Those respondents that give a protest response but have a travel cost greater than the bid proposed in the valuation question are recoded as an affirmative answer to the proposed payment. The economic justification lies in the minimum willingness to pay for enjoying the environment that travel cost reveals, while valuation question tries to obtain information about respondent maximum willingness to pay. Recoding allows to recover information and to improve estimates, accuracy. It also avoids computational complexity associated with sample selection models used to avoid biases derived from excluding protest responses.     

Does mode matter? A comparison of telephone,mail, and in-person treatments in contingent valuation surveys

The choice of survey mode in contingent valuation research has long been debated in the literature. However, there is limited evidence as to how mode impacts behavior. Using an identical survey administered with telephone, mail, and in-person interviews, this is the first research to examine mode effects using all three commonly employed modes in contingent valuation research. Results show that there is some evidence of social desirability bias in the telephone survey. In addition, the role of income in the decision-making process is an important consideration.     

Valuing damage to historic buildings using a contingent market: a case study of road traffic externalities

Pricing of road transport at social marginal cost should make users aware of the cost of damaging the environment (external costs). Such an approach, however, requires a monetary estimate of this damage which can be difficult to derive. On the basis of a study carried out at Neuchâtel (Switzerland), the contingent valuation method was used to estimate the damage caused to buildings of historical and cultural value by traffic‐caused air pollution. In a survey, individuals were asked to contribute to a fund set up to finance the maintenance of pre‐selected historic buildings. A valuation function to predict willingness‐to‐pay responses is estimated.     

Air quality assessment by contingent valuation in Ji'nan, China

Along with urbanization and environmental deterioration within China, many residents' desire for improved air quality has increased. To address this topic, this study focuses on the relationship between poor air quality and residents' willingness to pay for improved air quality in the city of Ji'nan. As a means of quantifying an individual's willingness to pay (WTP) for improved air quality, a contingent valuation method (CVM) was employed. A sample of 1500 residents was chosen, based on the stratified sampling method. The respondents' WTP was then elicited through a series of face-to-face interviews, conducted using a range of hypothetical, open-ended scenario questions. The results showed that 59.7% of respondents were able to express a positive WTP, and that the average WTP was 100 Chinese Yuan (CNY) per person, per year. In order to establish the relationship between endogenous variables and WTP, both a Probit model on the probability of a positive WTP, and a stepwise regression model were constructed. Most parameters in the econometric analysis demonstrated the expected results. It was found that annual household income, expenditure on the treatment of respiratory diseases and workers in the family significantly influenced WTP. The rates of positive WTP and the monetary amount were also larger for men than for women. Unlike developed countries, most respondents regard air quality improvement as a government responsibility in that more than 40% of respondents had no incentive to bear the costs of attempting to achieve better air quality, indicating a relatively low environmental consciousness.     

Integrating Wetland Management into Sustainable Water Resources Allocation: The Case of Akrotiri Wetland in Cyprus

This paper employs a contingent valuation (CV) study to estimate the value of the economic benefits generated by the Akrotiri wetland in Cyprus. It aims to show how CV estimation results can inform efficient, effective and sustainable wetland conservation policies, as required by the European Union's Water Framework Directive, and to suggest economic instruments that can facilitate the implementation of such policies. The results indicate that the design of these instruments require the capturing of both the use and non-use values generated by wetland services and functions.     

A contingent valuation of the Mar Lodge Estate,Cairngorm Mountains,Scotland

The contingent valuation method is applied to the economic valuation of a significant environmental resource in the Scottish Highlands. Use and non‐use values are estimated. The results of such studies might be used to assist decision makers assess the case for public intervention to support the provision of environmental non‐market goods.     

Impact of Perceived Importance of Ecosystem Services and Stated Financial Constraints on Willingness to Pay for Riparian Meadow Restoration in Flanders (Belgium)

The strategic importance of ecosystem service valuation as an operational basis for policy decisions on natural restoration has been increasingly recognized in order to align the provision of ecosystem services with the expectation of human society. The contingent valuation method (CVM) is widely used to quantify various ecosystem services. However, two areas of concern arise: (1) whether people value specific functional ecosystem services and overlook some intrinsic aspects of natural restoration, and (2) whether people understand the temporal dimension of ecosystem services and payment schedules given in the contingent scenarios. Using a peri-urban riparian meadow restoration project in Flanders, Belgium as a case, we explored the impacts of residents’ perceived importance of various ecosystem services and stated financial constraints on their willingness-to-pay for the proposed restoration project employing the CVM. The results indicated that people tended to value all the benefits of riparian ecosystem restoration concurrently, although they accorded different importances to each individual category of ecosystem services. A longer payment scheme can help the respondents to think more about the flow of ecosystem services into future generations. A weak temporal embedding effect can be detected, which might be attributed to respondents’ concern about current financial constraints, rather than financial bindings associated with their income and perceived future financial constraints. This demonstrates the multidimensionality of respondents’ financial concerns in CV. This study sheds light on refining future CV studies, especially with regard to public expectation of ecosystem services and the temporal dimension of ecosystem services and payment schedules.