Testing the Consistency Between Standard Contingent Valuation,Repeated Contingent Valuation and Choice Experiments

Choice experiments (CEs) are a relatively new approach to valuing environmental resources. Initial tests of the validity of the approach have either compared benefit estimates generated using CEs with those estimated using contingent valuation (CV) or used more sophisticated hypothesis tests of parameter equality. Although useful, existing tests have been restricted to testing consistency based on a single policy scenario (standard CV). We argue that, although these tests are informative, they fail to take full advantage of the richness of CE data. In particular, CE data allow for the calculation of benefit estimates over a range of policy scenarios (i.e. attribute combinations). A similar range of benefit estimates may be generated by pooling scenarios in a repeated CV study. In this paper, we explore this relationship between CV and CEs by conducting validity tests between a CE model and a repeated CV model over a range of three levels of improved water quality at Clear Lake, IA, USA. Evidence from this test suggests that the CE and CV data are consistent.     

Effect of Experimental Design on Choice-Based Conjoint Valuation Estimates

In this article, we investigate the effect of several commonly used experimental designs on willingness-to-pay in a Monte Carlo environment where true utility parameters are known. All experimental designs considered in this study generated unbiased valuation estimates. However, random designs or designs that explicitly incorporated attribute interactions generated more precise valuation estimates than main effects only designs. A key result of our analysis is that a large sample size can substitute for a poor experimental design. Overall, our results indicate that certain steps can be taken to achieve a manageably sized experimental design without sacrificing the credibility of welfare estimates.     

Design efficiency for non‐market valuation with choice modelling: how to measure it,what to report and why*

We review the basic principles for the evaluation of design efficiency in discrete choice modelling with a focus on efficiency of WTP estimates from the multinomial logit model. The discussion is developed under the realistic assumption that researchers can plausibly define a prior belief on the range of values for the utility coefficients. D‐, A‐, B‐, S‐ and C‐errors are compared as measures of design performance in applied studies and their rationale is discussed. An empirical example based on the generation and comparison of fifteen separate designs from a common set of assumptions illustrates the relevant considerations to the context of non‐market valuation, with particular emphasis placed on C‐efficiency. Conclusions are drawn for the practice of reporting in non‐market valuation and for future work on design research.     

Choice experiment adaptive design benefits: a case study*

Efficient experimental designs offer the potential to reduce required sample sizes, or to reduce confidence intervals for parameters of interest, in choice experiments. Choice experiment designs have typically addressed efficiency of utility function parameter estimates. The recently developed concept of C‐efficiency recognises the salience of willingness to pay estimates rather than utility function parameters in studies that seek to put money values on attributes. C‐efficiency design benefits have been illustrated in a theoretical context, but have not been tested in applied settings. This study reports a choice experiment field application that used initial responses to update statistical designs to maximise C‐efficiency. Consistent with theoretical predictions, the revised design delivered significant reductions in the variance of willingness to pay estimates, illustrating that C‐efficient designs can indeed decrease costs of choice experiments by reducing required sample sizes.     

Consumer sorting and hedonic valuation of wine attributes: exploiting data from a field experiment

This article uses a novel experimental approach to measure consumer willingness to pay (WTP) for wine attributes. We invited customers of a local supermarket who had selected a bottle of wine to purchase to participate in a valuation experiment. Integrating their original wine choice into the experiment, each participant evaluated six alternative wines, generating a rich set of data on willingness to pay and consumer characteristics. The data from the experiment allow us to compare standard shelf price‐based wine attribute valuation estimates with estimates using WTP data and an increasing amount of information about individual consumers. The full model employs individual fixed effects to estimate WTP parameters without bias from consumer sorting or supply side influences. Our WTP estimates for wine attributes differ markedly from previous attribute value estimates. Consumers in our sample display clear and stable preferences for wine varieties, but less clear preferences for appellations. Our results suggest caution is needed in using market prices to estimate parameters of the consumer valuation function for product attributes.     

How Sure Can You Be? A Framework for Considering Delivery Uncertainty in Benefit Assessments Based on Stated Preference Methods

The economic valuation of benefits resulting from environmental policies and interventions often assumes that environmental outcomes are certain. In fact, these outcomes are typically uncertain. This article proposes a methodological approach to incorporate delivery uncertainty into benefit estimation based on stated preference methods. In the study design of a choice experiment survey on land‐based climate change mitigation, we explicitly include delivery uncertainty as the risk that a proposed mitigation project fails to deliver emission savings. We find that respondents’ preferences do not change significantly after being confronted with choices that included risk of failure. However, failure risk itself does have an important impact on the preferences for delivering emission reductions. We show that delivery uncertainty can have a large impact on stated preference estimation of benefits of public programmes. This result should condition conclusions drawn from ex‐ante environmental cost‐benefit analyses that make use of such benefit estimates.     

A generalized method for valuing agricultural farms under uncertainty

The opacity of the farm market means that valuations are based primarily on expert estimates rather than on actual transaction prices. The valuation method based on the two cumulative distribution functions (VMTCDF), created by Ballestero (1971), improves the synthetic method based on estimating the market value of an asset by establishing a proportional relation between the asset and one external variable. However, in most cases the expert must consider multiple external variables. This paper proposes a definitive extension to k indexes with a methodology particularly applicable to the field of valuation of non-market goods or markets where little information is available as may be the case with the valuation of agricultural land. The contribution is illustrated with an empirical example.     

Ex‐ante Evaluation of Policy Measures: Effects of Reward and Punishment for Fertiliser Reduction in Palm Oil Production

Palm oil production creates negative externalities, e.g. through intensive fertiliser application. Policies to limit externalities need an effective, sustainable and efficient measure We use a business simulation game in a framed field experiment in Indonesia to test ex‐ante different incentives for reducing such negative externalities. This setting allows inclusion of adequate contextual features, required for reasonable ex‐ante evaluation of policy measures. The different designs of the test incentives (either a reward or punishment) varied in their magnitude and probability of occurrence but with constant effects on expected income. Results show that participants react differently to these incentives, indicating that the design can contribute significantly to effectiveness, sustainability or efficiency. A high reward with a low probability was found to be the most effective and sustainable incentive. Moreover, for the most efficient design, a low and certain reward is indicated.     

The value of green walls to urban biodiversity

Despite increased interest in the implementation of green walls in urban areas and the recognised benefits of monetary valuation of ecosystem services, no studies have been undertaken to estimate the economic value of biodiversity they provide. The valuation of natural resources allows policy makers to justify resource allocation. Using the Southampton, UK, as a case study, this paper estimates the public’s perceived value of green walls to urban biodiversity, in the form of their willingness to pay (WTP). Estimates were derived using a random parameter model that accounted for socio-economic and attitudinal determinants of choice, using choice experiment data. Three green infrastructure policies were tested; two green wall designs (‘living wall’ and ‘green façade’) and an ‘alternative green policy’; and compared against ‘no green policy’. Results indicated a WTP associated with green infrastructure that increases biodiversity. Attitudinal characteristics such as knowledge of biodiversity and aesthetic opinion were significant, providing an indication of identifiable preferences between green policies and green wall designs. A higher level of utility was associated with the living wall, followed by the green façade. In both cases, the value of the green wall policies exceeds the estimated investment cost; so our results suggest that implementation would provide net economic benefits.     

Value elicitation for multiple quantities of a quasi‐public good using open ended choice experiments and uniform price auctions

Choice experiments and experimental auctions have become popular mechanisms for estimating willingness to pay (WTP). However, these methods have primarily been used for estimating WTP for single units of goods. We analyze the results from experimental auctions and choice experiments in the context of multiple quantities of a quasi‐public good (animal welfare product). We show that the use of WTP values for a single unit of a product, a common practice in experimental valuation literature, can result in underestimation of aggregate demand. We use and compare open ended choice experiments (OECE), second price Vickrey auctions, and random Nth price auctions as mechanisms for valuing WTP. Our results also suggest that individual level demand estimates from OECE are less elastic than demand estimates from uniform price auctions.     

Toward understanding household preference for consumption characteristics of millet varieties: a case study from western Niger

In this study, we evaluate the preference of consumers in Niger for different tuwo or couscous characteristics using a random utility‐based choice experiment, ordered probit analysis, and tree‐based partitioning. Data were collected through a structured survey administered at four sites. Preferences are estimated for three products (couscous, fermented tuwo, and nonfermented tuwo) made from five pearl millet cutivars. We provide relative valuation for different traits by type of product. Results show that product taste, color, and textural attributes are important, especially for tuwo and couscous. Probit and partitioning results show that taste and color are the first attributes that consumers use to distinguish more preferred millet food products from less preferred millet food products. This should provide some direction for millet breeding programs and food processing of millet.     

Ambivalent statements in contingent valuation studies: inclusive response formats and giving respondents time to think

A recent concern in the valuation literature is the uncertainty respondents feel when posed with willingness-to-pay questions for environmental amenities in hypothetical market scenarios. Using a multiple-bounded discrete-choice format, the results indicate that respondents become less ambivalent when allowed considerable time to think about the valuation task before a response is elicited. In particular they tend to reduce the reported willingness to pay associated with low certainty of paying, hence resulting in more conservative welfare estimates. Implications for the application of environmental valuation techniques are discussed.     

Consumer versus citizen preferences in contingent valuation: evidence on the role of question framing*

Rather than individual consumer preferences, responses to referendum‐style contingent valuation surveys on environmental goods may express citizen assessments that take into account benefits to others. We reconsider the consumer versus citizen hypothesis with a focus on the role of framing information. Survey data on conservation areas in Ilomantsi, Finland, are used. Different versions of the valuation question were used to encourage the respondents to take the consumer or the citizen role. The citizen version expectedly resulted in substantially fewer zero‐WTP responses and protests and higher mean and median WTP, suggesting that the framing information has a major effect on the preferences expressed. The findings support the idea of multiple preferences. For a more confident interpretation of contingent valuation responses, future studies should recognise their intended use in survey design and gain information about respondents' motives to determine the presence and type of altruistic motives.     

Valuing Traits of Indigenous Cows in Central Ethiopia

This research aimed at identifying and estimating the relative weight assigned to the preferred traits of indigenous cow population in the most dominant crop–livestock mixed production system in Central Ethiopia. A choice experiment approach was employed to elicit the preferences and a random parameters logit model was used to estimate the relative importance of the preferred attributes of indigenous cows. The results show that fertility, disease resistance and calf vigour traits are at least as important as milk. The location the cows are brought from is also an important attribute for buyers. Results from the simulation on the influence of changes in attribute levels showed that fertility and disease resistance affect preferences more than other traits. The findings suggest that the smallholder community in this part of Ethiopia depends on semi‐subsistence agriculture and so livestock development interventions should focus on a multitude of reproductive and adaptive traits that stabilise the herd structure rather than focusing on traits that are only important for commercial purposes.     

Valuing traceability of imported beef in Korea: an experimental auction approach*

The major objective of this study is to estimate Korean food shoppers’ willingness to pay (WTP) for imported beef with traceability. We use an experimental elicitation method, the random nth price auction, to identify consumers’ valuation for traceable imported beef. We also analyse the effect of different types of information on these valuations. Results indicate that consumers are generally willing to pay a 39 per cent premium for the traceable imported beef over similar beef without traceability. Results also suggest that in contrast to the insignificant effect of positive information, negative and two‐sided information about traceability significantly reduces WTP.     

Including cost income ratio into utility function as a way of dealing with ‘exploding’ implicit prices in mixed logit models

The estimates of mean WTP are typically of main interest in non-market valuation studies. In the case of mixed logit models the distribution of WTP for an attribute is derived from the distribution of the ratio of individual coefficients. Since the cost coefficient enters the denominator, its distribution plays a major role in the distribution of WTP. A standard practice in analysing the data from choice experiments is to assume the cost coefficient is fixed, which implies that there is no heterogeneity in price sensitivity. The three most commonly given reasons for this are: (i) the distribution of the marginal willingness-to-pay for an attribute is then simply the distribution of that attribute's coefficient; (ii) in this way analysts wish to restrict the price variable to be non-positive for all individuals; and (iii) analysts avoid assuming log-normal cost because it is often found to produce behaviourally implausible estimates. Constraining a price coefficient to be fixed can however have serious consequences, i.e. a constant price coefficient implies that the standard deviations of unobserved utility is the same for all observations which can lead to biased results. Respondents are also likely to vary in price sensitivities, thus ignoring this variation can lead to erroneous interpretation and conclusions. In this paper we demonstrate a choice experiment exercise in which specifying a log-normal cost results in implausibly large WTP, however, adding into the utility function the cost income ratio prevents implicit prices from ‘exploding’.     

The Impacts of Elicitation Context on Stated Preferences for Agricultural Landscapes

Statements of willingness to pay (WTP) have been shown to be dependent upon the framing of the hypothetical market. In this paper we investigate the effects of variations in the timing and location of choice experiment questions concerned with conservation of a UK national park, as research involving measurement of psychological well‐being suggests potential differences for the same individual dependent upon when and where preferences are elicited. We apply the choice experiment technique to the valuation of changes in upland agricultural and semi‐natural landscapes in the Peak District National Park in the UK, to investigate whether timing and location of elicitation (context) affects the value associated with changes in ecosystem services under different management regimes. Four treatments are employed – using the same sample of individuals answering the same choice scenarios – to measure WTP ex‐ante (off site), in situ (on site), and ex‐post at two different time intervals (off site). We show that our on‐site (in situ) treatment generates very different estimates of preferences than any of the off‐site treatments. That stated preferences associated with environmental goods are so context dependent may have implications for the use of stated preferences in policy analysis in terms of identifying how environmental policy is funded and the divergence in value attributed to sampling different populations.     

A Comparison Between the Conventional Stated Preference Technique and an Inferred Valuation Approach

Contrary to conventional stated preference valuation techniques that employ a direct questioning approach, the inferred valuation method utilises indirect questioning where respondents are asked for their belief regarding others’ values for a good or service. In this study, using choice experiments, we compare the results obtained through the two valuation techniques for environmental features of the Burren landscape in western Ireland. Consistent with previous studies, stated values using the conventional approach are found to be significantly higher than those obtained through the inferred valuation approach. In particular, this study highlights the dissimilarities in relative preferences observed between the two landscape attributes (rocky limestone pavements and orchid‐rich grasslands) from the two questioning formats. While respondents were indifferent between the two habitats, they believed the ‘average other’ to be significantly more concerned about the conservation of the rocky limestone pavements. We attribute this divergence in preferences to be a consequence of additional normative motives perceived by respondents with regard to the conservation of orchid‐rich grasslands.     

Modelling property values in Nigeria using artificial neural network

Unreliable and inaccurate property valuation has been associated with techniques currently used in property valuation. A possible explanation for these findings may be due to the utilisation of traditional valuation methods. In the current study, an artificial neural network (ANN) is applied in property valuation using the Lagos metropolis property market as a representative case. Property sales transactions data (11 property attributes and property value) were collected from registered real estate firms operating in Lagos, Nigeria. The result shows that the ANN model possesses a good predictive ability, implying that it is suitable and reliable for property valuation. The relative importance analysis conducted on the property attributes revealed that the number of servants’ quarters is the most important attribute affecting property values. The findings suggest that the ANN model could be used as a tool by real estate stakeholders, especially valuers and researchers for property valuation.