A convergent validity test within the payment card format using simulation techniques

A convergent validity test is performed between two groups of versions of the payment card format. The first group, the classic payment card (CPC), asks respondents to report their willingness to pay (WTP) as a point from a list of amounts, and then treats each WTP response as an interval. The second group generates WTP data that may contain both single point and interval values. It includes the two-way-payment ladder (TWPL) (respondents have to tick amounts they would definitely pay and cross amounts they would definitely not pay), and point-interval payment card (PIPC) (respondents have to tick their WTP as either a point or an interval). The test is conducted using data from one TWPL study and two PIPC studies. For each study, we use WTP values stated to simulate 200 CPC WTP datasets, which allows controlling for any behavioral biases likely to confound the outcome of the test. The results challenge the conventional way of eliciting WTP under the CPC and the typical way of treating WTP data from this PC version. Although convergent validity holds between the TWPL/PIPC and CPC, parameter and mean WTP estimates from the TWPL and PIPC are more stable as PC intervals widths increase.     

Does Question Format Matter? Valuing an Endangered Species

A three-way treatment design is used to compare contingent valuation response formats. Respondents are asked to value an endangered species (the red-cockaded woodpecker) and the restoration of its habitat following a natural disaster. For three question formats (open-ended, payment card, and double-bounded dichotomous choice), differences in survey response rates, item non-response rates, and protest bids are examined. Bootstrap techniques are used to compare means across formats and to explore differences in willingness to pay (WTP) distribution functions. Convergent validity is found in a comparison of mean WTP values, although some differences are apparent in the cumulative distribution functions. Differences across formats are also identified in item non-response rates and proportion of protest bids. Overall, the payment card format exhibits desirable properties relative to the other two formats.     

Use of Contingent Valuation to Elicit Willingness-to-Pay for the Benefits of Developmental Health Risk Reductions

We report the results of several contingent valuation (CV) surveys to elicit willingness-to-pay values from the general public for risk reductions associated with decreases in exposure to a chemical, PCBs, in the environment. We also develop Quality Adjusted Life Years (QALYs) from the survey using both standard gamble and time-tradeoff elicitation methods to explore the relationship between QALYs and willingness-to-pay (WTP), and to develop QALY weights for subtle developmental effects. The results of the CV surveys are designed for incorporation into a case study of an integrated risk model to monetize the benefits of predicted risk reductions. Respondents showed a nearly proportional, positive relationship between decreasing the risk of a 6-point reduction in IQ (a standard measure of “intelligence”) and WTP, but showed a negative relationship between risk reduction and WTP for reading comprehension as an outcome. The range of mortality risks that respondents would accept on behalf of their (hypothetical) 10-year-old child is 2 in 10,000 to 9 in 1,000 per IQ point, and WTP per IQ point is $466 ($380, $520). QALY weights elicited via time tradeoff (reduction in life expectancy) were significantly different from QALY weights elicited via a standard gamble (p = 0.001). Respondents who answered questions about ecological endpoints first were willing to pay a small additional amount when asked about human health effects, but those respondents who answered questions about human health endpoints first were not willing to pay any additional amount when subsequently asked about ecological effects. This paper has not been submitted elsewhere in identical or similar form, nor will it be during the first three months after its submission to the Publisher.     

Dealing with Ignored Attributes in Choice Experiments on Valuation of Sweden’s Environmental Quality Objectives

Using a choice experiment, this paper investigates how Swedish citizens value three environmental quality objectives. In addition, a follow-up question is used to investigate whether respondents ignored any attributes when responding. The resulting information is used in model estimation by restricting the individual parameters for the ignored attributes to zero. When taking the shares of respondents who took both the environmental and the cost attributes (52–69% of the respondents) into account, then the WTP for each attribute changes if the respondents who ignored the attributes have a zero WTP. At the same time, we find evidence that not all respondents who claimed to have ignored an attribute really did. However, the most commonly ignored non-monetary attributes always have the lowest rankings in terms of WTP across all three environmental objectives. Thus, our results show that instead of ignoring attributes completely, respondents seem to put less weight on the attributes they claimed to have ignored.     

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.     

Asking for Individual or Household Willingness to Pay for Environmental Goods?

The aggregate welfare measure for a change in the provision of a public good derived from a contingent valuation (CV) survey will be higher if the same elicited mean willingness to pay (WTP) is added up over individuals rather than households. A trivial fact, however, once respondents are part of multi-person households, it becomes almost impossible to elicit an “uncontaminated” WTP measure that with some degree of confidence can be aggregated over one or the other response unit. The literature is mostly silent about which response unit to use in WTP questions, and in some CV studies it is even unclear which type has actually been applied. We test for differences between individual and household WTP in a novel, web-administered, split-sample CV survey asking WTP for preserving biodiversity in old-growth forests in Norway. Two samples are asked both types of questions, but in reverse order, followed by a question with an item battery trying to reveal why WTP may differ. We find in a test between samples that the WTP respondents state on behalf of their households is not significantly different from their individual WTP. However, within the same sample, household WTP is significantly higher than individual WTP; in particular if respondents are asked to state individual before household WTP. Our results suggest that using individual WTP as the response unit may overestimate aggregate WTP. Thus, the choice of response format needs to be explicitly and carefully addressed in CV questionnaire design and further research in order to avoid the risk of unprofitable projects passing the benefit-cost test.

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TRADE‐OFFS BETWEEN CIVIL LIBERTIES AND NATIONAL SECURITY: A DISCRETE CHOICE EXPERIMENT

We explore differences in perception of national security policies between self‐identified liberals, moderates, and conservatives from a national sample of U.S. adults. Using a discrete choice experiment, we also quantify each group's willingness to trade off select policies in exchange for reduced risk of a 9/11‐style terrorist attack. Relative to other groups, liberals are more likely to view such policies as ineffective and susceptible to government abuse. They also perceive a lower threat of terrorism. All groups are willing to make trade‐offs between civil liberties and risk of a terrorist attack. However, loss of civil liberties affects liberals more than conservatives. (JEL D61, H41, H56)     

Cognitive ability and scale bias in the contingent valuation method

This study investigates whether or not the scale bias found in contingent valuation (CVM) studies on mortality risk reductions is a result of cognitive constraints among respondents. Scale bias refers to insensitivity and non-near-proportionality of the respondents’ willingness to pay (WTP) to the size of the risk reduction. Two hundred Swedish students participated in an experiment in which their cognitive ability was tested before they took part in a CVM-study asking them about their WTP to reduce bus-mortality risk. The results imply that WTP answers from respondents with a higher cognitive ability are less flawed by scale bias.     

On the contingent valuation of mortality risk reduction in developing countries

Using the contingent valuation method in developing countries to value mortality risk reduction is particularly challenging because of the low level education of the respondents. In this article, we investigate whether some brief training regarding probability and risk concepts has any significant effect on the willingness-to-pay (WTP) responses. We elicit individuals’ risk perceptions by providing information on age specific mortality risks and find that people on average overestimate the mortality risk at younger ages and underestimate it at older ages. Our results indicate a significantly higher WTP for the trained sub-sample and WTP is sensitive to the magnitude of risk reduction for both the sub-samples.     

Dealing with preference uncertainty in contingent willingness to pay for a nature protection program: A new approach

In this paper, we propose an alternative preference uncertainty measurement approach where respondents have the option to indicate their willingness to pay (WTP) for a nature protection program either as exact values or intervals from a payment card, depending on whether they are uncertain about their valuation. On the basis of their responses, we then estimate their degree of uncertainty. New within this study is that the respondent's degree of uncertainty is “revealed”, while it is “stated” in those using existing measurement methods. Three statistical models are used to explore the sources of respondent uncertainty. We also present a simple way of calculating the uncertainty adjusted mean WTP, and compare this to the one obtained from an interval regression. Our findings in terms of determinants of preference uncertainty are broadly consistent with a priori expectations. In addition, the uncertainty adjusted mean WTP is quite similar to the one derived from an interval regression. We conclude that our method is promising in accounting for preference uncertainty in WTP answers at little cost to interviewees in terms of time and cognitive effort, on the one hand, and without researcher assumptions regarding the interpretation of degrees of uncertainty reported by respondents, on the other.     

Willingness to Pay and Sensitivity to Time Framing: A Theoretical Analysis and an Application on Car Safety

Stated preference (SP) surveys attempt to obtain monetary values for non-market goods that reflect individuals’ “true” preferences. Numerous empirical studies suggest that monetary values from SP studies are sensitive to survey design and so may not reflect respondents’ true preferences. This study examines the effect of time framing on respondents’ willingness to pay (WTP) for car safety. We explore how WTP per unit risk reduction depends on the time period over which respondents pay and face reduced risk in a theoretical model and by using data from a Swedish contingent valuation survey. Our theoretical model predicts the effect to be nontrivial in many scenarios used in empirical applications. In our empirical analysis we examine the sensitivity of WTP to an annual and a monthly scenario. Our theoretical model predicts the effect from the time framing to be negligible, but the empirical estimates from the annual scenario are about 70 % higher than estimates from the monthly scenario.     

Multivariate Mixed Models for Open-Ended Contingent Valuation Data: Willingness To Pay For Conservation of Monk Seals

Although dichotomous choice (DC) contingent valuation (CV) has been recommended by the US NOAA 'blue-ribbon' panel for large-scale contingent valuation studies, useful information can still be obtained from smaller, open-ended (OE) studies, often undertaken as a precursor to a DC survey. The CV study considered here was carried out in Greece and looked at willingness-to-pay (WTP) for protecting the Mediterranean monk seal (Monachus-monachus) in the Aegean area. This is the most endangered seal in the world, and the application of the CV methodology was the first such application in Greece. The OE data consist of two responses: first, a binary response detailing whether or not respondents were in principle prepared to pay for the protection of this seal; secondly, those respondents who answered 'yes' to the first question were then asked to state their maximum WTP for such protection. A multivariate binomial – log-normal mixture model is used to develop a bid function including explanatory variables such as income, sex, age and education. Such a modelling approach provides an alternative to more commonplace tobit estimation. However, the model is extended to include further information which was collected on:(a) an increased WTP amount given in response to information that the initial WTP amount may not be enough to prevent the extinction of the seal;(b) respondents were asked to divide their final WTP amount between use, option and existence values, the latter requiring a multivariate model with four binary and four continuous responses per individual in the same model.The discussion focuses on the methodological issues raised with some comment on the substantive interpretation of results.     

DRIVERS OF PAYMENT PATTERNS AT THE POINT OF SALE: STABLE OR NOT?

This research shows that it is key to have up‐to‐date information on payment behavior per type of point of sale (POS) and on how this behavior is driven by sociodemographic factors and perceived payment instrument attributes. Based on 2004 and 2014 data of the Netherlands, we find substantial shifts in the drivers of payment behavior. The sociodemographic factors behind the adoption of the credit card and debit card have changed, especially for the latter payment card. In addition, there are substantial shifts in the effects of sociodemographic factors and perceived relative payment attributes on which payment instrument consumers most often use. Shifts in payment behavior depend on the type of POS. Overall, we find that safety has become more important for payment behavior. The extent to which payment behavior depends on user‐friendliness and speed has somewhat decreased. (JEL C25, D12, E42)     

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 .     

Response Strategies and Learning in Discrete Choice Experiments

This study explores ordering effects and response strategies in repeated binary discrete choice experiments. Mechanism design theory and empirical evidence suggest that repeated choice tasks per respondent induce strategic behaviour. We find evidence that strategic opportunities provided by the order in which choice sets are presented to respondents affect choice decisions (strategic response). The results suggest, however, that respondents may solely respond to high cost rather than low cost inconsistencies. That is, respondents are more cost sensitive, and thus have a lower willingness to pay (WTP), if the same or a similar level of provision was offered in a previous choice set at a lower cost than if it was not. Yet, the cost sensitivity, and thus WTP, remains unaffected if the same or a similar level of provision was offered in a previous choice set at a higher cost. Our findings further indicate that cost sensitivity increases (and thus WTP decreases), when respondents progress through the choice task, with this increase (decrease) lessening as more choice questions are answered. Possible explanations are value learning and strategic learning.     

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.     

INEQUALITY IN MORTALITY OVER THE LIFE COURSE: WHY THINGS ARE NOT AS BAD AS YOU THINK

Recent research shows increasing inequality in mortality among middle‐aged and older adults. But this is only part of the story. Inequality in mortality among young people has fallen dramatically in the United States converging to almost Canadian rates. Increases in public health insurance for U.S. children, beginning in the late 1980s, are likely to have contributed. (JEL D63, I18, I38, J1, J3, J18)     

Are There Income Effects on Global Willingness to Pay for Biodiversity Conservation?

This paper is concerned with the empirical relationship between biodiversity conservation values and income. We use random effects panel models to examine the effects of income, and then GDP per capita, on willingness to pay for habitat and biodiversity conservation. In a meta-analysis, 145 Willingness To Pay estimates for biodiversity conservation where existence value plays a major role were collected from 46 contingent valuation studies across six continents. Other effects included in the meta-analysis were the study year; habitat type; continent; scope as presented to respondents; whether WTP bids were for preventing a deterioration or gaining an improvement in conservation, whether a specific species or specific habitat was protected; whether the questionnaire used a dichotomous choice or an open-ended format; distribution format; and the choice of payment vehicle. GDP per capita seemed to perform as well as an explanatory variable as respondent’s mean stated income, indicating that it is wealth in society as a whole which determines variations in WTP. Even if large variation, our main conclusion is, that the demand for biodiversity conservation rises with a nation’s wealth, but the income elasticity of willingness to pay is less than one.     

Willingness to pay for improving fatality risks and asthma symptoms: Values for children and adults of all ages

We examine effects of age on valuation of mortality and morbidity risks using a two-stage contingent valuation survey and a sample including parents of children aged 4–17 years and adults aged 18–92. The survey used a hypothetical improved asthma therapy to elicit (1) tradeoffs between asthma control and fatality risk, (2) willingness to pay (WTP) for reduced fatality risk, and (3) WTP for asthma control. The mean value of statistical life (VSL) at average age is $3.8M, but age affects VSL and nonlinearly. Estimated VSL is highest at age four ($14.1M), falls until age 30 ($3.7M), rises until age 66 ($6.7M), and then falls to $1.5M by age 92. Results from the wide age range considered may partly reconcile apparently conflicting results from previous studies focused on narrower age ranges. The value of asthma control is not as strongly related to age as VSL and ranges from $1700 to $4000 annually.     

Distributional Preferences and the Incidence of Costs and Benefits in Climate Change Policy

We explore the relationship between willingness to pay (WTP) for climate change mitigation and distributional preferences, by which we mean individuals’ opinions about who should be responsible for climate change prevention and whether the share of climate change impacts borne by the poor is a cause for concern. We use 1,770 responses to an online stated preference survey. The domestic costs in our survey’s policy choice scenarios are expressed as a set of randomized shares across four different payment vehicles, and the international cost shares are randomized across four groups of countries. We also elicit respondents’ perceptions of the likely regressivity of climate change impacts under a policy of business-as-usual. WTP is higher when larger cost shares are borne by parties deemed to bear a greater responsibility for mitigation, and when respondents believe (and care) that the impacts of climate change may be borne disproportionately by the world’s poor. That WTP for an environmental policy depends on the distributional consequences of the policy is an unsettling result: efficiency assessments are typically assumed to be separate from equity considerations in most benefit-cost analyses.