The impact of the bird flu on public willingness to pay for the protection of migratory birds

In this paper, we present the results of a unique time series analysis of contingent values and models for migratory bird protection based on an identical contingent valuation (CV) survey carried out over a three year time period since the first bird flu outbreak in 2003. Although there exists no scientific evidence for a direct relationship, migratory birds are believed to play an important role in spreading the bird flu virus worldwide. The time series analysis allows us to test the temporal stability of stated preferences for migratory bird protection and at the same time examine indirectly the possible impact of increased media attention and public awareness levels regarding the bird flu. We test the impact of the bird flu on public willingness to pay (WTP) for migratory bird protection in the final 2005 survey whilst accounting for procedural variance introduced by sequencing and question ordering-effects, but we are unable to demonstrate a direct negative relationship. A novelty of the study presented here is that respondents in the CV surveys are given the opportunity to pay an annual money amount or a one-time-off lump-sum. Annual WTP values appear to be significantly higher than one-time-off WTP values, suggesting a negative implicit discount rate. Self-selection bias is an important reason for the observed differences. We find that respondents who agree to pay annually differ significantly from respondents who wish to pay a lump-sum in terms of their underlying preferences and motivations towards migratory bird protection.     

A Meta-study Investigating the Sources of Protest Behaviour in Stated Preference Surveys

It is a well-known empirical finding that some percentage of respondents participating in Stated Preference surveys will not give responses that reflect their true preferences. One reason is protest behaviour. If the distribution of protest responses is not independent of respondent or survey characteristics, then simply expelling protesters from surveys can lead to sample selection bias. Furthermore, WTP estimates will not be comparable across surveys. This paper seeks to explore potential causes of protest behaviour through a meta-study based on full datasets from 38 different surveys. The objective of the study is to examine the effect of respondent specific variables as well as survey specific variables on protest behaviour. Our results suggest that some of the differences in WTP typically observed between different demographic groups, different elicitation formats and different question formats might actually be attributed to inherent differences in the propensity to protest. Our results indicate that the propensity for respondents to exhibit protest behaviour when asked a stated preference type valuation question depends on a number of specific factors, respondent specific as well as survey specific—knowledge which could be used in order to reduce protest behaviour.     

WILLINGNESS TO PAY FOR AIR QUALITY: THE CASE OF OUTDOOR EXERCISE

This study uses a contingent valuation (CV) survey to establish a sample of outdoor exercisers' willingness to pay (WTP) for ambient air quality improvements in East Baton Rouge parish, Louisiana. Estimated annual median and mean WTP values are £95 and £191, respectively, per person per year for assurance that ozone levels would not become "unhealthful" on any day. The survey informed respondents that in the prior year the local community experienced 14 days on which ozone levels exceeded federal standards. The study makes the strong assumptions that respondents believed they were "buying" 14 more healthy days and that WTP per day "bought" is constant. Given these assumptions, one can scale this WTP response to represent annual medians and means of approximately £7 and £14 per person per day, respectively. An econometric procedure for generalizing the community's annual WTP to avoid the 14 unhealthful days yields estimates ranging from £3.21 and £5.36 per person per healthy day, or between £12.4 and £20.6 million per year. The unit day estimates are comparable to CV and household production finction estimates of WTP in the Los Angeles basin, suggesting their usefulness for benefits transfer .     

Marginal WTP and Distance Decay: The Role of ‘Protest’ and ‘True Zero’ Responses in the Economic Valuation of Recreational Water Quality

We evaluate the sensitivity of distance decay in individuals’ stated willingness to pay (WTP) for water quality improvements in eutrophied lakes. We extend the standard model of contingent valuation (CV) by allowing individuals to adopt a sequential evaluation process consisting of two decision stages. In the first stage respondents decide whether they are ‘protesters’, have a WTP   \(=\)   ‘true zero’ or a \(\hbox {WTP}>0\) . Conditioned on a strictly positive WTP, we use Lee’s selectivity-corrected model to determine the magnitude of their WTP in the second stage. Using CV survey data from Norway we find significant distance decay in the first stage classification of respondents as ‘protesters’, ‘true zero’ WTP, or positive WTP. In the second stage model for positive WTP responses, we find little or no significant relationships when correcting for selection. Results suggest that previous findings of significant distance decay in contingent valuation of lake and river water in Europe may be driven by the definition of ‘protest’ and ‘true zero’ respondents. We find that WTP for water quality may be more useful as a qualitative indicator of political support for user financed water quality measures, than as a cardinal measure of marginal utility of water quality improvements.     

Combining stated and revealed choice research to simulate the neighbor effect: The case of hybrid-electric vehicles

According to intuition and theories of diffusion, consumer preferences develop along with technological change. However, most economic models designed for policy simulation unrealistically assume static preferences. To improve the behavioral realism of an energy–economy policy model, this study investigates the “neighbor effect,” where a new technology becomes more desirable as its adoption becomes more widespread in the market. We measure this effect as a change in aggregated willingness to pay under different levels of technology penetration. Focusing on hybrid-electric vehicles (HEVs), an online survey experiment collected stated preference (SP) data from 535 Canadian and 408 Californian vehicle owners under different hypothetical market conditions.Revealed preference (RP) data was collected from the same respondents by eliciting the year, make and model of recent vehicle purchases from regions with different degrees of HEV popularity: Canada with 0.17% new market share, and California with 3.0% new market share. We compare choice models estimated from RP data only with three joint SP–RP estimation techniques, each assigning a different weight to the influence of SP and RP data in coefficient estimates. Statistically, models allowing more RP influence outperform SP influenced models. However, results suggest that because the RP data in this study is afflicted by multicollinearity, techniques that allow more SP influence in the beta estimates while maintaining RP data for calibrating vehicle class constraints produce more realistic estimates of willingness to pay. Furthermore, SP influenced coefficient estimates also translate to more realistic behavioral parameters for CIMS, allowing more sensitivity to policy simulations.     

Valuing Mortality Risk in Kuwait: Stated-Preference with a New Consistency Test

We report stated-preference estimates of the value per statistical life (VSL) for Kuwaiti citizens obtained using an innovative test to identify respondents whose survey responses are consistent with economic theory. The consistency test requires that an individual report strictly positive willingness to pay (WTP) for mortality-risk reduction and that his responses to binary-choice valuation questions for two risk reductions be consistent with the theoretical requirement that WTP is less than but close to proportional to the change in risk reduction. Our estimates of VSL, $18–32 million, are approximately two to four times larger than values accepted for the United States. These values may reflect cultural factors as well as the substantially larger disposable income of Kuwaiti citizens.     

‘Adopt a Hypothetical Pup’: A Count Data Approach to the Valuation of Wildlife

The willingness to pay (WTP) for a coyote conservation program is estimated using a novel payment-vehicle, based on how many ‚problem’ coyotes respondents would be willing to sponsor for a year. This hypothetical scenario mimics an increasingly popular type of actual market. Data from a phone survey conducted in Prince Edward Island are analyzed using count data models that consider different processes explaining zero responses and the level of positive responses. This is particularly important in the case of coyotes, often regarded as an economic bad. Estimates of WTP per coyote per year around $18–$22 and annual WTP per contributor of about $46–$57 are obtained.      

Money matters: an axiomatic theory of the endowment effect

We develop a framework that allows us to state precisely the relationship between leading concepts of the theoretical and empirical research on reference-dependent preferences, namely the status quo bias, the endowment effect and the willingness to accept (WTA)/willingness to pay (WTP) gap. We show that a monetary version of the status quo bias is a necessary condition for the WTA/WTP gap, and show how to factor out the part of the gap due to income effects from the part of the gap due to the endowment effect. As a byproduct, we show that reference-dependent phenomena are generated by reference-independent factors, i.e., an underlying reference-independent preference relation the properties of which are discussed at length.     

Spatial Heterogeneity of Willingness to Pay for Forest Management

The paper investigates the spatial heterogeneity of public’s preferences for the implementation of a new country-wide forest management and protection program in Poland. Spatial econometric methods and high resolution geographical information system data related to forest characteristics are used to explain the variation in individual-specific willingness to pay (WTP) values, derived from a discrete choice experiment study. We find that respondents’ WTP is higher the closer they live to their nearest forest, and the scarcer forests are in the area where they live. Interestingly, the higher the ecological value of forests in respondents’ area, the more people prefer extending areas of national forest protection. We also investigate spatial patterns in individual-specific WTP scores and in latent class membership probabilities, finding that preferences are indeed spatially clustered. We argue that this clustering should be taken into account in forest management and policy-making.     

Giving Stated Preference Respondents “Time to Think”: Results From Four Countries

Previous studies have found that contingent valuation (CV) respondents who are given overnight to reflect on a CV scenario have 30–40% lower average willingness-to-pay (WTP) than respondents who are interviewed in a single session. This “time to think” (TTT) effect could explain much of the gap between real and hypothetical WTP observed in experimental studies. Yet giving time to think is still rare in binary or multinomial discrete choice studies. We review the literature on increasing survey respondents’ opportunities to reflect on their answers and synthesize results from parallel TTT studies on private vaccine demand in four countries. Across all four countries, we find robust and consistent evidence from both raw data and multivariate models for a TTT effect: giving respondents overnight to think reduced the probability that a respondent said he or she would buy the hypothetical vaccines. Average WTP fell approximately 40%. Respondents with time to think were also more certain of their answers, and a majority said they used the opportunity to consult with their spouse or family. We conclude with a discussion of why researchers might be hesitant to adopt the TTT methodology.     

The missing piece: Valuing averting behavior for children's ozone exposures

Individuals can reduce their exposure to air pollution by reducing the amount of time they spend outdoors. Reducing outdoor time is an example of an averting behavior that should be measured as part of willingness to pay (WTP) for improvements in air quality. In this paper, we estimate parents’ WTP to prevent restrictions on a child's outdoor time from a stated-preference (SP) conjoint survey. We combine this WTP measure with an estimate of reductions in time spent outdoors on high-ozone days from an activity-diary study to estimate this averting behavior component of WTP for reductions in ozone pollution.     

Valuing climate protection through willingness to pay for biomass ethanol

This study uses a multi-part, split-sample contingent valuation method (CVM) and fair share (FS) survey to better understand the public's valuation of mitigating global climate change through its willingness to pay for biomass or “cellulosic” ethanol. In addition to a basic CVM question, a related scenario was developed that asked half of the survey respondents to state their fair share cost to lessen a potential food shortage in the next decade, also through the expanded use of cellulosic ethanol. Three alternative biomass feedstocks were assessed: farming residues, forestry residues and paper mill wastes, and municipal solid wastes. Overall a slightly larger proportion of respondents were WTP extra for cellulosic ethanol in the basic CVM scenario than in the FS scenario, though no significant differences were found in the WTP for the different feedstocks. Bid curve lognormal regression results for the two models were similar, supporting the idea that asking a FS rather than a conventional WTP question may be justifiable in some circumstances, such as in cases of a national emergency.     

A comparison of empirical models used to infer the willingness to pay in contingent valuation

The essence of the contingent valuation method consists of creating a hypothetical market where respondents are asked about their willingness to pay (WTP) for a non-market good. Different empirical models can be formulated to estimate the expected WTP of a sample of respondents and, then, through aggregation, the social valuation of the good is inferred.This paper outlines the relevance of the distributional assumptions when estimating mean WTP. Several parametric and non-parametric methods are discussed and applied to calculate the existence value of a natural space. Results show that WTP is extremely sensitive to the empirical model used.First version received: November 2002 / Final version received: January 2004     

Are Internet surveys an alternative to face-to-face interviews in contingent valuation?

Internet is an increasingly popular data collection mode for stated preference research in environmental economics. However, little is known about how this survey mode may influence data quality and welfare estimates. As part of a national contingent valuation (CV) survey estimating willingness to pay (WTP) for biodiversity protection plans, we assign two groups of respondents either to an Internet or face-to-face (in-home) interview mode. Our design aims to better isolate measurement effects from sample composition effects by drawing both samples from the same sample frame. We find little evidence of social desirability bias in the interview setting or satisficing (shortcutting the response process) in the Internet survey. The share of “don't knows”, zeros and protest responses to the WTP question with a payment card is very similar between modes and equality of mean WTP cannot be rejected. Results are fairly encouraging for the use of Internet in CV as stated preferences do not seem to be significantly different or biased compared to face-to-face interviews.     

Willingness to pay for QALY: perspectives and contexts in Japan

Abstract

Objectives: Theoretically, willingness-to-pay (WTP) for quality-adjusted life years (QALY) can vary depending on social and personal preferences and on ex-ante and ex-post settings. However, empirical investigations into the theoretical differences are lacking. In Japan, setting the threshold has been controversial since a pilot project to implement health technology assessments (HTA) launched in 2016. The study aim is to estimate WTP values for one additional QALY from different perspectives, health statuses, and contexts to confirm the difficulty in setting a uniform price threshold using WTP.

Methods: More than 1,000 respondents representing a cross-section of the Japanese population answered each of nine questionnaire decks in an online panel. WTP values were estimated on three different perspectives (personal, social, and socially inclusive) and on two contexts (ex-ante and ex-post). This study primarily used the non-parametric spike model based on double-bounded dichotomous choice (DBDC) settings to obtain the conditional WTP values.

Results: WTP per QALY was higher in the severe health status than in the moderate health status from all perspectives. Respondents from the socially inclusive perspective estimated the highest WTP value for a new drug. Respondents were also asked about life-threatening diseases in ex-post and ex-ante. The WTP value in ex-ante was higher than in ex-post, and demographic factors affecting the WTP were different in both situations. The various WTP values were obtained from these surveys.

Limitations: The analysis was based on data collected from an internet panel, which could be biased. There is also a risk that respondents answered the questionnaire differently if asked in everyday situations.

Conclusion: Use of a uniform price threshold may not be appropriate in policy settings, because it may not reflect diverse preferences based on different situations, such as disease type and severity. Setting a price threshold as Japan institutes an HTA system requires further research.     

Choosing Between Internet and Mail Survey Modes for Choice Experiment Surveys Considering Non-Market Goods

In a choice experiment setup considering a non-market good, this paper adds to the literature on survey mode effects by providing evidence that internet surveys can be a viable alternative to traditional mail surveys when gathering feedback from a sample of respondents. The case study concerns preferences for protecting different types of landscape from road encroachment when building new motorways in Denmark. Two samples of respondents are surveyed—one by internet and one by mail. The performances of the two samples are compared over six different criteria; response rates, protest responses, demographics, preferences and WTP, estimation precision, and, finally, certainty in choice. Differences are observed for some of these criteria, implying that analysts should be aware that choosing internet over mail could be accompanied by a survey mode effect. However, the observed differences do not translate into significant differences in the unconditional WTP estimates. In most applied economic valuation studies of non-market goods, the main objective is in fact estimation of WTP. Hence, in the present case, the identified survey mode effects do not severely invalidate the applicability and continued use of the internet as a suitable means of collecting data for choice experiment economic valuation of non-market goods.     

Sensitivity of Willingness to Pay Estimates to the Level of Attributes in Discrete Choice Experiments

This paper considers issues raised in the application of discrete choice experiments (DCEs) to estimating willingness to pay (WTP). The main issue addressed is the sensitivity of WTP estimates to the level of attributes. A DCE, concerned with preferences for alternative cervical screening programmes, was carried out with women in the Tayside area of Scotland. A split sample design was employed in which respondents were divided into two groups. Each group received a discrete choice questionnaire that varied with respect to the levels of three of the six attributes. The price attribute was one of the attributes that varied across questionnaires. Whilst estimated coefficients were not significantly different across five of the six attributes included in the experiment, mean WTP estimates were significantly different for four of the five welfare estimates. However, from a policy point of view, such a difference may not be important. Consideration is also given to other general methodological and policy issues that are raised when using DCEs to estimate WTP. The findings suggest the need for further research into the design and application of DCEs as a method for estimating WTP.     

Preferences for improvements in attributes associated with basal insulin: a time trade-off and willingness-to-pay survey of a diabetic and non-diabetic population in Sweden

Objective: Apart from improved health outcomes, treatment convenience per se may have a value to individuals. This is sometimes referred to as process utility and can be estimated in terms of willingness-to-pay (WTP) or quality-adjusted life-years (QALYs). Previous research has produced multiple studies on QALY gains and WTP estimates of insulin-related attributes. There are, however, significant variations between studies, and it is not clear to what extent the value is a reflection of the true preferences or a consequence of the methodological approach. The aim of this study is to estimate the preferences for treatment attributes associated with basal insulin (administration frequency, administration flexibility, and treatment-induced weight gain) using both QALYs—elicited using time trade-off (TTO) and WTP—among a sample of the Swedish general population and among a sample of the Swedish diabetes population.

Methods: Data was collected using web-based surveys which were distributed to members of internet panels. The WTP survey presented five hypothetical scenarios with an offer to pay the incremental cost to receive basal insulin with improved attributes. The TTO survey presented six hypothetical scenarios where the respondent could choose between living for the rest of his/her life with diabetes and receiving treatment with a basal insulin with certain attributes or live for a shorter time with full health. The scenarios were combined with either a basal or a basal–bolus treatment regimen. Results from the TTO analysis were translated into monetary estimates using a threshold value of SEK500,000 per QALY.

Results: In total, 2012 responses were included. The ratings of the attributes were almost identical, irrespective of method for the general population, while it differed to some extent for the diabetes population. The methods produced the same value for flexibility, but the estimates generated with the TTO approach were higher for one less injection and avoided weight gain. The general population assigned a higher utility gain to convenience attributes, while the diabetes population assigned a higher utility gain to avoiding weight gain.

Limitations: About a quarter of the respondents did not accept the scenario in the WTP survey, i.e. protesters.

Conclusions: The ranking of the attributes was generally independent of evaluation method, but the TTO method resulted in similar or higher values compared to the WTP method.     

Binary Choice Valuation Studies with Heteregeneous Preferences Regarding the Program Being Valued

We investigate the effect of respondents' heterogeneous preferences regarding the good to be valued in binary-choice contingent valuationstudies. This is especially important when the valuation options give rise to both highly negative and highly positive attitudes.The survey design employs questionnaires which include separate items for willingness to favorandwillingness to contribute in monetary terms to the provision of the good. In light of our analysis, eliciting respondents' differentpreferences for the project first, without monetary considerations, wouldimprove the WTP estimates as welfare measures. Our results alsosuggest that nonparametric estimation could offer another solution foraccounting for preference heterogeneity. Nonparametric estimation is less sensitive to those `no' responses which are in fact not intended toreflect the respondents' WTP as such but merely to express their dislikefor the good at issue.     

Respondent direct experience and contingent willingness to pay for new commodities: a switching endogenous interval regression analysis

Most environmental economists argue that direct experience with the good being valuated, or with similar goods, is a precondition for providing valid willingness to pay (WTP) responses to contingent valuation questions. Two questions are posed in this article. The first is whether previous use experience of a resource (Séné nature reserve) similar to that being valuated (future nature reserves) and located in the same geographical area (Gulf of Morbihan) impacts on WTP. The second is whether accounting for the endogeneity of direct experience matters in the estimation of WTP. We find that respondents who have not experienced the Séné nature reserve provide value estimates that are statistically comparable to that of respondents who have experienced it. Our assumption is that respondents have acquired sufficient and adequate experience of future nature reserves from the questionnaire that experience obtained by experiencing the Séné nature reserve was not necessary for making a valid value formulation. Hence, aggregation of WTP estimates to obtain a total valuation of the future nature reserves is reasonable over the full target population. In addition, our results show that direct experience is endogenously determined; but controlling for the endogeneity has a marginal effect on WTP estimates.