Addressing Heterogeneous Preferences Using Parametric Extended Spike Models

Some public programs simultaneously provide a mix of non-rejectable public goods and public bads. Consequently, some individuals would pay for the program, while others might instead need to becompensated. In this paper we estimate twoparametric extended spike models that accountfor positive and negative preferences as wellas indifference for the public good. Weillustrate the models using data on valuationof prescribed burning of underbrush in forests,which reduces the risk of catastrophicwildfires but also produces smoke emissions(the public bad). We compare the two empiricalapproaches to estimate willingness to pay (WTP)for the program and contrast these results withthose obtained from modeling specificationsthat only account for non-negative preferences.Substantial differences in public net benefitswere found between the most flexible parametricextended spike model and the simple spike modelwhere negative responses were coded as zero anda standard binary logit of only positivebidders. The results from the extended spikemodels demonstrated that accounting forindifference and negative values towards thepublic good resulted in substantially lowerwillingness to pay estimates.     

意愿调查法在房屋拆迁补偿价格评估中的运用——以武汉市为例

房地产拆迁是近年来最敏感的社会问题之一,评估结果是否准确直接影响着被拆迁人、拆迁人、政府三方的切身利益,进而影响拆迁工作的进程。针对拆迁补偿价格评估现存难题,引入意愿调查法(CVM),探讨了其在房屋拆迁补偿价格评估中的优势、全面设计了调查程序、提出偏差解决方法,并设计调查问卷以武汉市为实证研究,得出受偿意愿金额(WTA);最后对意愿调查法的实际应用提出三点建议。     

Contingent valuation of inhaled insulin: a Canadian perspective

Summary

The objective of this study was to assess the preference and willingness-to-pay (WTP) for inhaled insulin from a random sample of general public perspective in Ontario, Canada. This was carried out using a mail survey using the contingent valuation method. Significantly more respondents preferred inhaled insulin (n=114) over subcutaneous insulin (n=6; p<0.001). The mean monthly WTP for inhaled insulin was CAN$68.59 ± 44.65 (95% confidence interval CAN$58.87–78.07), significantly more than the average subcutaneous insulin cost in Ontario of CAN$50. The WTP for inhaled insulin in the diabetic subgroup was CAN$98.52 ± 48.57, which is significantly higher than that of the general public (p<0.001). Multiple regression analysis showed a strong association between respondents’ income and diagnosis of diabetes and their WTP for inhaled insulin (p<0.001). Major influencing factors were convenience and household budget. The results of this study suggest that the general public in Ontario prefer inhaled insulin and are willing to pay significantly more per month than the current cost of subcutaneous insulin.     

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.     

The Environmental Supply of Farm Households: A Flexible Willingness to Accept Model

The purpose of the paper is toanalyse farmers' participation inenvironmental schemes, which are gaining agrowing importance within the Europeanagricultural policy. These schemes areimplemented through voluntary contracts thatpay farmers for the provision of environmentalservices. The microeconomic model that isdeveloped is a farm household model thatincorporates the producer and consumerbehaviour of the farmer to optimise hisenvironmental supply considering that theenvironmental service that he is supplying alsohas the characteristics of a public good. Defined as the difference between the profitloss in providing the environmental service andthe willingness to pay to consume this service,the household's willingness to accept (WTA)is compared with two flexible WTA measures thataccount for the technological flexibility ofthe environmental supply. Data come from asurvey of an agri-environmental schemeimplemented in the Walloon region of Belgiumsince 1995 and intended to protect the nestingof some endangered bird species. Econometricresults show that contingent valuation is areliable method to reveal the behaviours offarmers facing the invitation to participate inthis scheme. They also confirm that farmerbehaviour is also influenced by environmental preference.     

Why Give up Money for the Baltic Sea? – Motives for People's Willingness (or Reluctance) to Pay

A contingent valuation survey about a reduction of the eutrophication of the Baltic Sea provided data about respondents' motives for their answers to the willingness to pay question. A categorization of the motives allowed an identification of protesters against the valuation scenario. The categorization also illustrated that a teleological ethical perspective is not shared by all respondents and that some respondents perceive human indirect use of ecosystems.     

Who would pay more for a fragrance-free laundry detergent? How health information affects valuation

Fragrance allergy is a lifelong condition, and the probability of being affected increases with frequent exposure to fragrance. Currently, fragrance-free laundry detergents are not common in supermarkets. We used a contingent valuation among Austrian consumers in a within-respondent treatment to estimate how willingness to pay is influenced by health information. We found that higher income groups have a higher willingness to pay for fragrance-free detergents. Informing consumers about health impacts substantially increases this difference. Our simulation shows that lower-income groups benefit from health information only if low-priced fragrance-free detergents are available on the market.     

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.     

Empirical Evidence Showing The Relationships Between Three Approaches for Pollution Control

Willingness to pay models have shown the theoretical relationships between the contingent valuation, cost of illness and the avertive behaviour approaches. In this paper, field survey data are used to compare the relationships between these three approaches and to demonstrate that contingent valuation bids exceed the sum of cost of illness and the avertive behaviour approach estimates. The estimates provide a validity check for CV bids and further support the claim that contingent valuation studies are theoretically consistent.     

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.     

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.     

Elicitation Format and Sensitivity to Scope

This paper undertakes a systematiccomparison of the contingent valuation (CV) andchoice experiments (CE) methods, andinvestigates the extent to which either of themare affected by insensitivity to scope. This isachieved by undertaking separate CV estimatesof willingness to pay for two nested publicgoods, both of which are explicitly included ina parallel CE survey. The results indicate thatCE values exhibit greater sensitivity to scopethan CV values. CE gives significantly largerresults than CV for the more inclusive publicgood and significantly smaller results for theless inclusive public good.     

Productivity and technical change: the case of Taiwan

This paper analyses productivity growth in 16 of Taiwan's manufacturing industries during the period 1978–1992. The non-parametric Data Envelopment Analysis approach is used to compute Malmquist productivity indexes. These are decomposed into efficiency change and technical change. The latter is further decomposed into an output bias, an input bias and a magnitude component. In addition, the direction of input bias is identified. Empirical results indicate that the sector's TFP increased at a rate of 2.89% per annum, which could be ascribed to a technical progress (2.56%) and an efficiency improvement (0.33%).     

我国失地农民状况及受偿意愿调查报告

近70%的农民不愿意土地被征用,主要原因是补偿不到位或者补偿数额难以满足农户的要求;调查样本所获得的平均土地征用补偿与其平均支付意愿之间相差5倍;农民在土地征用中掌握的信息越充分,转让土地的倾向越高。因此,在征地过程中,应充分保障被征地农民的知情权,通过法律赋予农民转让土地的\"还价权\"。     

The market value of preventive activities: A contingent-claims approach

We use a contingent-claims approach to determine the market value of preventive investments. We show that the lower the initial probability of accident, the greater is the market value of a reduction in this probability. Besides, at initially low probabilities, ceteris paribus, the market gives a higher value to a reduction in accident probability when aggregate (correlated) catastrophic risks rather than independent ones are involved. The reverse occurs at initially high probabilities.     

Treating respondent uncertainty in contingent valuation: A comparison of empirical treatments

This research examines the impact of uncertainty on contingent valuation responses using (1) a survey of Canadian landowners about willingness to accept compensation for converting cropland to forestry and (2) a survey of Swedish residents about willingness to pay for forest conservation. Five approaches from the literature for incorporating respondent uncertainty are used and compared to the traditional random utility model with assumed certainty. The results indicate that incorporating uncertainty has the potential to increase fit, but could introduce additional variance. While some methods for uncertainty can be an improvement over traditional approaches, it is imperative to exercise caution when making systematic judgments about the effect of uncertainty on contingent valuation responses.