The willingness to pay–willingness to accept gap: A failed replication of Plott and Zeiler

The well-known willingness to pay–willingness to accept (WTP–WTA) gap refers to the observation that individuals attach a higher value to objects they own (WTA) than to objects they do not own (WTP). We report on experiments to re-investigate the possibility that the WTP–WTA gap arises from subject misconceptions due to experimental procedures as suggested by Plott and Zeiler (2005). The contribution of this paper is two-fold: first, we attempt to replicate the findings by Plott and Zeiler that the WTP–WTA gap disappears when using procedures that are aimed at reducing misconceptions, such as extensive training and practice rounds for the BDM mechanism. However, we fail to do so as the WTP–WTA gap persists in the main task where subjects state their WTA or WTP for a mug. Second, we use the paid practice rounds to identify subjects without apparent misconceptions and find that also for those subjects who never make dominated choices in the lottery tasks, the WTP–WTA gap in the mug task exists. Thus, we find no evidence of the idea that subject misconceptions are the main source of the WTP–WTA gap.     

Noxious Facilities, Environmental Damages, and Efficient Randomized Siting

This paper considers the efficient siting of a noxious facility that causes environmental damages (for example, increased pollution) in the host community. The analysis shows that there can be multiple efficient locations without transfers, and that an efficient location need not have the smallest WTA or WTP. In general, there exist randomized outcomes that are ex ante efficient and that Pareto dominate efficient outcomes. The analysis also shows that a community’s most preferred lottery never provides full insurance. Under some conditions, lotteries with no host compensation are Pareto superior to those with compensation.     

Modelling the Non-market Environmental Costs and Benefits of Biodiversity Projects Using Contingent Valuation Data

CV studies rarely ask willingness to accept (WTA)questions, yet there are a range of environmentalprojects where there are likely to be potential losersas well as gainers. This paper presents evidence fromsix biodiversity projects that the inclusion ofcontingent compensation payments from thoserespondents who preferred the status quo cansubstantially reduce net project benefits, even whenthe proportion of losers is relatively small. Astatistical model for estimating the mean welfaremeasure from dichotomous choice data which allows forboth positive WTP, zero WTP, and WTA is described. Asmany environmental projects are likely to create bothgainers and losers, we recommend that CV analysts giveserious consideration to the collection and analysisof WTA data otherwise they risk generating biasedestimates of project benefits.     

Reference Dependence Effects on WTA and WTP Value Functions and Their Disparity

In this study we investigate two reference dependence effects in a choice experiment. The first is the effect of the well-known distinction between gains and losses, the second is the effect of changing the reference value on willingness to pay (WTP) and willingness to accept (WTA). The latter has to our knowledge not been studied before. We hypothesize that there are differences between WTA and WTP, and that both value functions and their disparity are affected by the absolute value of the reference point. We test our hypotheses using a choice experiment with trade-offs between changes in flood probabilities and costs. The choice experiments elicit WTP and WTA, using two flood probability reference values, yielding four separate value functions. Our findings show that a substantial WTA–WTP disparity exists, and that this disparity increases when moving away from the reference point. Also, both WTA and WTP value functions are affected by the flood probability reference value, and the WTA–WTP disparity increases when the flood probability reference point increases. Both findings suggest that welfare effects caused by changes in public good provision depend not only on the direction of change (loss aversion), but also the reference value. Moreover, our results show that the latter effect is larger for losses than for gains. We introduce the concept of reference point updating as a possible explanation for these findings.     

The impact of behavioural risk-reduction interventions on willingness to pay to avoid sexually transmitted infections: a stated preference study of justice-involved youth

Risky health behaviours, such as smoking, drinking and risky sex, are substantial contributors to the U.S. morbidity rates and healthcare costs. While economic models typically regard preferences as stable, a growing literature suggests that information, including how it interacts with intentions and attitudes, plays an important role in unhealthy behaviours. Relatedly, a large health literature demonstrates that theory-based behavioural interventions can successfully change risky behaviour. This study uses the contingent valuation (CV) survey method to investigate the impact of behavioural interventions on a novel outcome measure: the willingness to pay (WTP) to avoid the consequences associated with risky behaviour. Using novel pre- and post-intervention data from Project MARS (Motivating Adolescents to Reduce Sexual Risk), this study estimates the impact of the intervention on elicited WTP to avoid sexually transmitted infections (STIs). It is found that after the intervention, participants’ elicited WTP to avoid STIs were significantly higher, and more sensitive to differences in infection severity. These results suggest that the intervention may affect risky sexual behaviour by changing the perceived value of avoiding the consequences of risky sexual behaviour. Additionally, these findings contribute to an ongoing debate regarding the construct validity of CV studies in health economics.     

The Aggregation of Climate Change Damages: a Welfare Theoretic Approach

The economic value of environmental goods is commonly determined using the concepts of willingness to pay (WTP) or willingness to accept (WTA). However, the WTP/WTA observed in different countries (or between individuals) will differ according to socio-economic characteristics, in particular income. This notion of differentiated values for otherwise identical goods (say, a given reduction in mortality risk) has been criticized as unethical, most recently in the context of the 'social cost' chapter of the IPCC Second Assessment Report. These critics argue that, being a function of income, WTP/WTA estimates reflect the unfairness in the current income distribution, and for equity reasons uniform per-unit values should therefore be applied across individuals and countries. This paper analyses the role of equity in the aggregation of climate change damage estimates, using basic tools of welfare economics. It shows one way of how WTP/WTA estimates can be corrected in aggregation if the underlying income distribution is considered unfair. It proposes that in the aggregation process individual estimates be weighted with an equity factor derived from the social welfare and utility functions. Equity weighting can significantly increase aggregate (global) damage figures, although some specifications of weighting functions also imply reduced estimates. The paper also shows that while the postulate of uniform per-unit values is compatible with a wide range of 'reasonable' utility and welfare specifications, there are also cases where the common-value notion is not compatible with defensible welfare concepts.     

Men earn less under working time accounts: a puzzle?

In recent years more and more working time accounts (WTA) have been introduced. From a theoretical perspective both employers and employees benefit from such an instrument. Indeed, empirical studies show that life satisfaction of workers is larger under a WTA regime than under a non-WTA regime. However, more detailed investigations in this article reveal wages to be lower for men under WTA regimes. Why should men accept WTA when they earn less? Subgroup analyses show that these results are only valid for some groups of individuals. Our analysis allows us to deliver some explanations and to exclude other possible reasons. The major results are: (1) High-income workers suffer higher losses; (2) the shorter the compensation period of WTA systems the lower the wage reduction imposed by WTA; (3) the length of total working time does not seem to affect the link between WTA and wages but the length of overtime; (4) men accept wage losses from WTA if they can adjust actual to desired working hours.     

Despairing Over Disparities: Explaining the Difference Between Willingness to Pay and Willingness to Accept

This paper examines the three major explanations for the disparity between willingness-to-pay (WTP) and willingness-to-accept (WTA) observed in contingent value surveys and laboratory experiments: a belief that the results must be biased in some fashion, Hanemann's (1991) substitutes hypothesis, and the loss aversion model proposed by Tversky and Kahneman (1991). Starting from the assumption that individuals make utility maximizing choices, we develop structural equations that yield parametric tests of the hypotheses within a single, non-experimental framework. The approach is flexible enough to incorporate a variety of functional form and distributional assumptions and can be applied to either data from either open-ended bids or dichotomous choice questions. The usefulness of the approach is demonstrated using data from a survey that asked both WTP and WTA questions. The results provide weak support for loss aversion.     

Auction mechanisms and the measurement of WTP and WTA

We evaluate the impact of three auction mechanisms — the Becker–DeGroot–Marschak mechanism, the second-price auction, and the random nth-price auction — in the measurement of willingness to pay (WTP) and willingness to accept (WTA) measures of value. Our results show that initial bidding in trial 1 in each auction does not contradict the endowment effect; but that, if it is the endowment effect that governs people’s initial bidding behavior, it can be eliminated with repetitions of a second-price or random nth-price auction; and if the thesis is that the effect should persist across auctions and across trials is right, our results suggest that there is no fundamental endowment effect.     

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.     

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.     

Past and present outage costs – A follow-up study of households’ willingness to pay to avoid power outages

Households’ demand for electricity continues to increase. This trend per se should indicate increased disutility from power outages. Additionally, batteries and other back-up systems have been improved, and the frequency and duration of outages have been reduced in many countries. By comparing the results from two stated preference studies on Swedish households’ willingness to pay (WTP) to avoid power outages in 2004 and 2017, we investigate whether the WTP has changed. The WTP is assessed for power outages of 1- and 4 -h durations, and whether it is planned or unplanned. We find three main differences: (i) the proportion of households stating zero WTP to avoid power outages decreased significantly from 2004 to 2017, meaning that more households are willing to pay to avoid a power outage in 2017 than in 2004; (ii) the overall WTP was considerably higher in 2017 than in 2004, but (iii) the conditional WTP, that is, WTP for those that have a positive WTP for an outage, has decreased. These results have implications for how regulators incentivize and regulate electricity suppliers, because the results suggest that a reliable supply of electricity is of greater importance now than what the literature has suggested.     

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.     

A field experiment to estimate the effects of anchoring and framing on residents’ willingness to purchase water runoff management technologies

Watersheds throughout the world have been severely polluted by nutrient-laden runoff that comes from industrial, agricultural, and residential sources. Efforts to reduce this runoff have focused on industrial and agricultural sources, while little attention has been paid to encouraging residents to reduce runoff from their properties. To study residents’ willingness to adopt landscaping practices that reduce runoff, we conducted a field experiment in the Delaware River watershed. In the experiment, over three hundred adults participated in a series of random-price auctions that revealed their willingness to pay (WTP) for five products that reduce nutrient runoff. To study how WTP can be influenced by attributes of the choice architecture, we randomized the starting bid values (anchors) and the way in which the external benefits of the five practices were framed. Compared to a neutral framing, a positive framing (using the product can improve water quality) increased average WTP by about one-third, while the estimated effect of a negative framing (failing to use the product can worsen water quality) was also positive, but smaller and not statistically different from zero. The estimated effect on average WTP from the anchor depends on how bids of $0 are modeled, but the results imply that higher anchors lead to higher WTP. Although we believe the magnitudes of our results should be considered suggestive and we recommend replications with higher statistical power, the results add to the evidence base that environmental programs can achieve policy-relevant gains in program performance through a series of small changes to the decision environment.     

Can unbiased be tighter? Assessment of methods to reduce the bias-variance trade-off in WTP estimation

This paper aims at verifying the claim, appeared in recent literature, that it is possible to control for response bias associated to the double bound elicitation method, while keeping gains in efficiency of the WTP estimates. Results from a Monte Carlo analysis lead, in general, to reject the claim; but when initial bids are not correctly chosen, the gains in efficiency are confirmed. An empirical application dealing with WTP estimation for drinking water quality improvements illustrates a case where a flexible modeling approach based on Copula distributions allows relevant gains with respect to the Single Bound estimator.     

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.     

The Value of Household Water Service Quality in Lahore,Pakistan

Most existing literature focuses on the benefits of establishing basic drinking water access for unserved populations, the extensive water supply margin. In contrast, this article examines the intensive margin—the benefits of improving water service to under-served households, a growing population in developing country cities. We use contingent valuation to estimate willingness to pay (WTP) for improved piped water quality and reductions in supply interruptions among a sample of 193 households in Lahore, Pakistan. The distribution of WTP is described using parametric and non-parametric models. Results indicate that households in Lahore are willing to pay about 7.50 to7.50 to 9 per month for piped water supply that is clean and drinkable directly from the tap—comparable to the monthly cost of in-home water treatment, and about three to four times the average monthly water bill for sample households using piped water. Estimates of WTP for reducing supply interruptions are both smaller and more difficult to interpret, since a significant fraction of the estimated WTP distribution for supply improvements is negative. All of our WTP estimates are well below 4% of monthly household income, the World Bank’s benchmark upper bound for affordable water service.     

城市饮用水水源地生态补偿标准测算与资金分配研究——以广东省东江流域为例

生态补偿作为解决城市饮用水源地生态环境保护问题,协调保护方和受益方利益冲突的重要手段,已成为国内外学者研究的热点,其中补偿标准是决定生态补偿能否顺利实施的关键环节。选取珠江三角洲城市群重要饮用水水源地——广东省东江流域作为研究对象,在总结分析现有补偿标准的基础上,运用生态保护成本法和条件价值评估法,分别从流域水源地保护方和下游受益方的角度对东江流域生态补偿标准进行测算,并依据下游用水量对补偿金进行分摊。通过测算,广东省东江流域上游六县生态保护总成本为105.38亿元,其中直接成本5.40亿元,间接成本99.98亿元,引入水质修正系数和水量分摊系数后,下游四市应补偿上游六县的生态补偿额度为24.69亿元。下游四市生态补偿支付意愿总额为5.91亿元,应支付总补偿额度超出支付意愿总额18.79亿元。因此,在充分考虑流域上游生态保护成本和下游支付意愿、支付能力的前提下,利益相关双方通过谈判、协商在生态补偿标准问题上达成一致,对东江流域生态环境保护和生态补偿机制的建立有着重要的现实意义。     

Values of Gains and Losses: Reference States and Choice of Measure

The available empirical evidence continues to suggest that people commonly value losses more, and often much more, than otherwise commensurate gains. Consequently, current practice of using the WTP measure for all changes is often likely to lead to misleading assessments of welfare changes. The reference dependence of preferences implies instead that while the WTP measure is appropriate for gains, the value of both positive and negative changes in the domain of losses will usually be more accurately assessed with the WTA measure.     

A framework for estimating willingness-to-pay to avoid endogenous environmental risks

This paper proposes a general empirical strategy to estimate willingness-to-pay (WTP) for exogenous risk mitigation when environmental risks are endogenous in protective actions and consumers are imperfectly informed about the ambient risk levels. The strategy consists of a set of survey techniques and the dummy endogenous variable model (Heckman, 1978) to control for correlation in unobserved errors that enter the WTP equation and the protection-decision equation. The method is applied to the non-market valuation survey data on arsenic contamination in drinking water. Our results indicate that the estimated WTPs are significantly higher for households without self-protective action. Our approach thus offers not only the correct welfare estimate for exogenous reduction of environmental risks, but also yields policy implications qualitatively much different from the conventional approach. We also estimate the welfare value of the policy to inform and educate the public about the arsenic risk simultaneously with public risk mitigation. The estimated welfare value is similar to, though slightly higher than, that of risk mitigation without information component. This occurs due to the competing effects of information dissemination and risk mitigation efforts.