Willingness to pay for publicly-financed health care: how should we use the numbers?

This paper addresses the question of how willingness to pay (WTP) values in health care evaluation can be used by policy makers. The way in which WTP values are used depends on from whom values are elicited and whether the good concerned is privately-financed or publicly-financed through taxation. Thus, four possible uses of WTP values are identified. The focus is on the two uses which arise in the publiclyfinanced situation. ‘Conventional’ use of WTP values, where the decision as to whether or not to provide a service depends upon whether or not WTP values are greater than total cost, applies only in the privately-financed, and not publiclyfinanced situations. The situations with publicly-financed goods are more complex. The use of WTP values for publicly-financed goods is justified and illustrated.     

Addressing Negative Willingness to Pay in Dichotomous Choice Contingent Valuation

This paper has four purposes. First, we outline the controversy surroundingthe issue of negative willingness to pay (WTP)in contingent valuation (CV) studies. Second,we use Monte Carlo simulation to examine theperformance of alternative distributionalassumptions in estimating WTP in the presenceof varying proportions of the populationholding negative WTP values. We focus ondichotomous choice CV (DC-CV), where negativeWTP values may be especially difficult todetect. Third, we extend the simulation toinvestigate the performance of the mixturemodels that have recently been proposed forhandling/identifying non-positive WTP values. Fourth, we extend the simulation to investigatethe performance of the nonparametric lowerbound Turnbull approach. Results indicate thatthe relative performance of the DC-CV modelingalternatives evaluated here, which assumepositive WTP, varies across the simulationsetting (e.g., proportion of negative WTP); butnone can be said to reasonably ``solve' theproblem ex post. This underscores theimportance of ex ante efforts to identify ifnegative WTP is likely to be prominent in agiven valuation setting. In such cases,appropriately handling negative WTP must beaddressed through ex ante survey design andmodeling choices that allow negative WTP.     

Bayesian Conjoint Choice Designs for Measuring Willingness to Pay

In this paper, we propose a new criterion for selecting efficient conjoint choice designs when the interest is in quantifying willingness to pay (WTP). The new criterion, which we call the WTP-optimality criterion, is based on the c-optimality criterion which is often used in the optimal experimental design literature. We use a simulation study to evaluate the designs generated using the WTP-optimality criterion and discuss the design of a real-life conjoint experiment from the literature. The results show that the new criterion leads to designs that yield more precise estimates of the WTP than Bayesian D-optimal conjoint choice designs, which are increasingly being seen as the state-of-the-art designs for conjoint choice studies, and to a substantial reduction in the occurrence of unrealistically high WTP estimates.     

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.     

Willingness to Pay for Forest Property Rights and the Value of Increased Property Rights Security

This paper studies the willingness to pay (WTP) for forest property rights in Viet Nam. We do so by asking respondents to estimate the value of two different forest property rights regimes where only the level of property security differs and all other forest plot characteristics are constant. We use this information to identify the value of the property rights security. Our results reveal that a significant number of individuals are willing to pay for an additional area of forestland but that the amount offered appears to be inadequate to compensate sellers, as very few land market transactions actually take place. The results further indicate that income relates positively to WTP, irrespective of forest property regime. Wealth, age, and ethnicity also have an impact on the amount households are willing to pay. As expected, there was a significant mark-up on the more secure right. Econometric estimates of the difference between the WTP for secure and insecure property rights show that a higher level of female education, and household age decrease the difference between the two WTP measures while the difference tends to increase as income improves. This has important policy implications, as it indicates that households tend to evaluate the property rights institutions differently.     

Trading Taxes vs. Paying Taxes to Value and Finance Public Environmental Goods

The potential sensitivity of environmentalresource valuation to payment vehicles is ofinterest to researchers and decision-makersinvolved in estimating and applying thesenumbers. A conceptual model is developed whichprovides insight into how the different paymentvehicles of a special tax and a taxreallocation affects the willingness to pay(WTP) for environmental goods. Hypothesistesting using contingent valuation datasuggests WTP with a tax reallocation is higherthan WTP with a special tax for ground waterquality protection in Georgia and Maine, USA.Technical measurement and welfare analysisimplications and limitations of valuing andfinancing public environmental goods using taxrealloactions are discussed.     

Willingness to pay to control PM2.5 pollution in Jing-Jin-Ji Region,China

This letter aims to study individual willingness to pay (WTP) to mitigate PM_2.5 pollution in the Jing-Jin-Ji region by using contingent valuation method. Our survey indicated that residents in this region were highly concerned about PM_2.5 pollution control and supported PM_2.5 pollution control policies. In this study, a payment card (PC) format is used to elicit residents’ perceived WTP. With a two-part model, we estimate the mean WTP for an 80% reduction of severe PM_2.5 polluting days in this region is 602 CNY a year, approximately accounts for 1% of the GDP per capita. This result indicates an important funding source for the government to control PM_2.5 pollution in the region. In the econometric analysis, the mean WTP is found to significantly relate with income, expense, age and education level. It decreases with income, age and educational level, but increases with expense, and it is higher for females, people who have children, own cars and apartments but lower for those having larger families. By comparing with relevant researches, this letter indicates a strong and ever-increasing WTP for air pollution control among residents in the Jing-Jin-Ji region, China.     

Willingness to pay for improved air quality in Sweden

The aim of the paper is to quantify individual willingness-to-pay measures of improved air quality in Sweden by using the Contingent Valuation Method (CVM). Such measures are important for policy makers when deciding about public investments and policy instruments in order to regulate environmental impacts, e.g. from road transportation and industry. The mean willingness to pay (WTP) for a 50% reduction of harmful substances where the respondents live and work was about 2000 SEK/year, which is of the same order of magnitude as earlier stated preference studies in Nordic countries. Most parameters in the econometric analysis had the expected sign. WTP was increasing in income, wealth and education; it was larger for men, members of environmental organizations, people living in big cities (which are on average more polluted), and people who own their house or apartment. It was lower for retired people. However, the additional WTP for people in big cities, although significantly higher than for other people, was lower than expected, indicating a possible insensitivity-to-scope effect.     

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.     

Willingness to pay for other species' well-being

Benefit-cost analysis of environmental policies typically focuses on benefits to human health and well-being. For other species, economists have attempted to measure human WTP for changes in the numbers of individuals for different types of wildlife, and to preserve biodiversity. When it comes to humans' WTP for improvements in the quality-of-life for other species, however, the evidence is limited. Morbidity and quality-of-life considerations may be particularly important to the task of valuing non-fatal harm to wildlife in the wake of an environmental disaster. We argue that the other species morbidity-reduction component of WTP should be calculated net of any “outrage” component associated with the cause of the harm. This net WTP is likely to be correlated with the premium that people are willing to pay for chicken products from birds for which the quality-of-life has been enhanced by improved animal welfare measures. This paper uses a conjoint choice stated preference survey to reveal the nature of systematic heterogeneity in preferences for “humanely raised” versus “conventionally raised” chicken. We also use latent class analysis to distinguish between two classes of people—those who are willing to pay a premium for humanely raised chicken, and those who are not.     

The Willingness to Accept Value of Statistical Life Relative to the Willingness to Pay Value: Evidence and Policy Implications

Large disparities between willingness to accept (WTA) and willingness to pay (WTP) based values of statistical life are commonly encountered in empirical studies. Standard economic theory suggests that if a public good is easily substitutable there should be no marked disparity between WTA and WTP values for the good, though the disparity increases with reduced substitutability. However, psychologists have shown that people often treat gains and losses asymmetrically and tend to require a substantially larger increase in wealth to compensate for a loss than the amount they would be willing to pay for an equivalent gain. Although most transport projects may aim to improve safety, situations arise when a relaxation of an existing regulation saves resources but increases the risk of death and injuries. A survey was recently carried out in New Zealand to determine people’s willingness to pay to reduce road risks and their willingness to accept compensation for an increase in risk. This paper reports the disparity observed between the two measures and considers some of the problems posed for policymakers.     

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.     

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.     

Choice Consistency and Preference Stability in Test-Retests of Discrete Choice Experiment and Open-Ended Willingness to Pay Elicitation Formats

This study tests the temporal stability of preferences, choices and willingness to pay (WTP) values using both discrete choice experiment (DCE) and open-ended (OE) WTP elicitation formats. The same sample is surveyed three times over the course of two years using each time the same choice sets. Choice consistency is positively correlated with choice certainty and choice complexity. The impact of choice complexity fades away in time, most likely as a result of learning and preference refinement. Although the OE WTP values remain stable over a time period of 2 years as in previous stated preference studies, DCE based WTP measures differ significantly, suggesting their use in benefits transfer may be limited.     

城乡居民对水源地保护的支付意愿差异分析——以北京水源地为例

基于城乡比较的视角,利用调查数据,运用意愿调查法分析了城乡居民对水源地保护的支付意愿及其差异。研究结果显示:虽然农村居民的收入较低,但是农村居民对水源地保护的响应程度要高于城区居民,且农村居民对水源地保护的户均支付意愿也高于城区居民,但农村居民的总支付意愿比城区居民小;从支付意愿的影响因素来看,城区居民与农村居民并没有表现出明显的差异性,即均表现为受教育程度、家庭收入对支付意愿有显著的正向影响,而年龄对支付意愿有显著的负向影响;从拒绝支付的理由来看,绝大多数农村居民拒绝支付的主要原因是收入低、没有能力支付,而超过半数的城区居民认为水源地保护是政府、自来水公司等其他主体的责任。     

The Effect of Risk Characteristics on the Willingness to Pay for Mortality Risk Reductions from Electric Power Generation

The objective of this study is to estimate willingness to pay (WTP) for the reduction of mortality risks caused by fossil fuel (natural gas, coal and oil) versus nuclear electric power generation systems and to examine the influence of risk characteristics involved with electric power generation on WTP. A choice experiment was conducted to achieve these objectives. The attributes for nuclear risks in the experiment included the probability of disasters and the expected losses if a disaster occurs. We find evidence of (i) a baseline effect (where WTP is sensitive to hypothetical versus actual baseline expected mortality); (ii) a ‘labeling effect,’ where, surprisingly, the term ‘nuclear’ has no effect on WTP, but the term ‘fossil-fueled power generation’ results in lower WTP; and (iii) disaster aversion, meaning that people focus on the conditional loss from a nuclear disaster, not the probability. We also find that the WTP for reducing deaths from a nuclear disaster is about 60 times the WTP for routine reducing fossil-fuel generation-related deaths.     

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.     

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.     

Willingness to Pay for Car Safety: Evidence from Sweden

This study estimates a marginal willingness to pay (WTP) function for a road-mortality risk reduction. Observed marginal WTP from the Swedish car market is used and found to be positively correlated with the baseline risk of the cars. No statistically significant relationships between examined owner attributes, e.g. wealth and background risk, and marginal WTP are found. When comparing the estimated monetary value of a non-marginal risk reduction derived from the integral of the marginal WTP-function with an estimate based on marginal WTP we find, in line with expectations, that the difference between the estimates is negligible for smaller risk reductions and small, 4–10%, also for relatively large risk reductions.      

农户生活垃圾处理支付意愿及影响因素分析——基于对南水北调中线工程水源地的调查分析

农村生活垃圾处理对提高农民生活水平,保持村容整洁具有十分重要的意义。以南水北调水源区农户为调查对象,分析农户对生活垃圾处理的认知及支付意愿。实证结果显示:58.29%的农户愿意为保护生活环境进行付费,平均付费金额为10.57元;影响农户支付意愿的关键因素为:教育程度、政治身份、性别、对环境污染的认知、收入水平。