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.     

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 assumption of equal marginal utility of income: how much does it matter?

In most applied cost–benefit analyses, individual willingness to pay (WTP) is aggregated without using explicit welfare weights. This can be justified by postulating a utilitarian social welfare function along with the assumption of equal marginal utility of income for all individuals. However, since marginal utility is a cardinal concept, there is no generally accepted way to verify the plausibility of this latter assumption, nor its empirical importance. In this paper, we use data from seven contingent valuation studies to illustrate that if one instead assumes equal marginal utility of the public good for all individuals, aggregate monetary benefit estimates change dramatically.     

Endowment effect theory,prediction bias and publicly provided goods: an experimental study

Many studies report on a systematic disparity between the willingness to pay for a certain good (WTP) and the willingness to accept retribution payments in exchange for giving up this good (WTA). Thaler [Thaler RH (1980) J Econ Behav Organ 1:39–60] employs prospect theory to explain this disparity. The literature contains two different interpretations of his endowment effect theory. Accordingly, the disparity is caused either by the disutility from parting with one’s endowment and/or by an extra utility from ownership which is not anticipated by individuals who are not endowed with the good. So far, the empirical evidence on the applicability of endowment effect theory is limited to private goods. This paper reports on an experiment which finds a significant ownership utility effect for a publicly provided good. This result indicates that prospect theory applies to publicly provided goods even though consumers do not have exclusive property rights.      

Evaluating public goods from individual welfare functions

This paper suggests a method for evaluating public goods based directly on individual welfare functions. A hypothetical project for reducing air pollution is used as an illustration. The paper describes a technique for estimating welfare functions: the approach is applied to a limited experimental sample. The individual marginal rates of substitution between air income are then added up in order to yield estimates of values associated with air quality variations by the group under consideration. Further it is illustrated that the utilization in the aggregation process of heights based on individual differences in marginal utility of income as computed from the welfare functions, can modify the measures of social profitability and yield evaluation more consistent with basis criteria of social welfare.     

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.     

The random expenditure function approach to welfare in RUM: The case of hazardous waste clean-up

This paper presents an application of the random expenditure function approach for welfare analysis in RUM with a non-linear income effect. The measures of expected compensating variation (CV) are first derived as special cases to apply to a two-option conjoint choice-based survey data aimed at deciphering homeowners’ willingness to pay for hazardous waste clean-up. A comparison of the expected CV with the CV based on the representative consumer approximation (CVr) reveals high degree of agreement between the estimates. Using the Diewert and Translog utility specifications the study finds that regardless of the methodology used, welfare estimates are quite sensitive to the functional forms.     

Discrete Choice Experiments in Developing Countries: Willingness to Pay Versus Willingness to Work

A concern when conducting stated preference valuation studies in rural developing or very low income contexts is the use of monetary willingness to pay (WTP) estimates. In circumstances where cash incomes are extremely low, a significant proportion of the population are not engaged in waged labour and the exchange of goods or services is augmented through barter or work exchange, the role of money is likely to be different from that within an urban developed setting. As such, ability to pay using money may be impaired and downwardly biased when compared with other mediums of exchange. In recognition of this several studies have used hypothetical labour contributions as payment vehicles and a common finding is that households are more often willing to contribute labour than they are money. In this paper we present the results of a split sample DCE using money and labour contributions as payment vehicles for improved drinking water quality in Kandal Province, Cambodia. We find little differences between the payment vehicles in terms of attribute non-attendance, marginal utilities of attributes or derived welfare values. We argue that this provides support for the use of WTP in rural developing areas where there are functioning labour markets.     

Comparing Fuzzy and Probabilistic Approaches to Preference Uncertainty in Non-Market Valuation

In seeking to value environmental amenities and public goods, individuals often have trouble trading off the (vague) good or amenity against a monetary measure. Valuation in these circumstances can best be described as fuzzy in terms of the amenity being valued, perceptions of property rights, and the numbers chosen to reflect values. In this paper, we apply fuzzy logic to contingent valuation, employing a fuzzy clustering approach for incorporating preference uncertainty obtained from a follow-up certainty confidence question. We develop a fuzzy random utility maximization (FRUM) framework where the perceived utility of each individual is fuzzy in the sense that an individual’s utility belongs to each cluster to some degree. The model is then applied to a Swedish survey that elicited residents’ willingness to pay for enhanced forest conservation and to a Canadian survey of agricultural landowners that elicited their willingness to accept compensation for a tree planting program. Both the WTP and WTA measures we obtain using the fuzzy approach are well below those obtained using standard probability methods. Based on goodness of fit measures and Monte Carlo experimentation, a case can be made for using a fuzzy preference approach for modeling preference uncertainty as opposed to incorporating respondent uncertainty within the random utility maximization framework.      

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.     

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.     

WTA Estimates Using the Method of Paired Comparison: Tests of Robutness

The method of paired comparison is modified to allow choices between two alternative gains so as to estimate willingness to accept (WTA) without loss aversion. The robustness of WTA values for two public goods is tested with respect to sensitivity of the WTA measure to the context of the bundle of goods used in the paired comparison exercise and to the scope (scale) of the public good project. There was no statistical difference in WTA measures for open space based on independent treatments with different contexts. One treatment involved valuing open space within a set of goods with similar value. The other treatment involved valuing open space within a choice set of goods which had lower dollar values than open space. There was a statistical difference in WTA between a permanent expansion in the bus system and a temporary expansion in the bus system. We conclude the method of paired comparison appears to be a very promising approach to elicit measures of WTA.     

调查评价法在非景区型森林景观价值评估中的应用

针对非景区型森林景观具有公共物品的特性,运用调查评价法评估其经济价值。在星子县大排岭瓷土矿区森林景观价值评估中,477个样本的人均支付意愿为66.86元,以白鹿镇人口为基数,计算大排岭矿区森林景观的总价值为1 671 834元。在支付意愿相关性分析中发现:收入与支付意愿中度相关(r=0.64,p<0.01),职业、学历与支付意愿低度相关(r=0.352&0.367,p<0.01),年龄、性别与支付意愿不相关。     

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.     

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.     

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.     

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.     

Temporal stability of preferences and willingness to pay for natural areas in choice experiments: A test–retest

The main objective of this paper is to test the temporal stability of stated preferences and willingness to pay (WTP) values from a Choice Experiment (CE) in a test–retest. The same group of participants was asked the same choice tasks in an internet-based CE, conducted twice with a time interval of one year without interviewer interference. We examine choice consistency at individual choice task level and transferability of the underlying indirect utility function and associated WTP values. The results show that choices are consistent in 57 percent of the choice occasions. Comparison of the choice models over time shows that the estimated preference and scale parameters are significantly different, suggesting that choice behaviour changed between the two surveys. Differences between marginal WTP estimates for individual choice attributes are statistically significant only at the 10 percent level. However, we show that this can result in significantly different WTP values for policy scenarios. The instability of estimated mean WTP values for different policy scenarios asks for caution when including WTP values in cost-benefit analysis.     

Mixed logit estimation of willingness to pay distributions: a comparison of models in preference and WTP space using data from a health-related choice experiment

Different approaches to modelling the distribution of WTP are compared using stated preference data on Tanzanian Clinical Officers’ job choices and mixed logit models. The standard approach of specifying the distributions of the coefficients and deriving WTP as the ratio of two coefficients (estimation in preference space) is compared to specifying the distributions for WTP directly at the estimation stage (estimation in WTP space). The models in preference space fit the data better than the corresponding models in WTP space although the difference between the best fitting models in the two estimation regimes is minimal. Moreover, the willingness to pay estimates derived from the preference space models turn out to be very high for many of the job attributes. The results suggest that sensitivity testing using a variety of model specifications, including estimation in WTP space, is recommended when using mixed logit models to estimate willingness to pay distributions.     

Exchange Rules and the Incentive Compatibility of Choice Experiments

The incentive properties of stated-preference surveys continue to be a central debate in the valuation of public goods. The majority of empirical studies have focused on incentive properties of contingent valuation questions in relation to situations where answers have monetary consequences. This research explores the incentive properties of repeated, attribute-based choice questions when subjects are provided with an explicit connection between choices and outcomes. Two market/provision-rules are investigated: a posted-price market and a plurality-rule vote. These two provision rules are contrasted to treatments in which no provision rule is discussed—subjects are simply asked to choose their preferred alternative. These three hypothetical choice treatments are compared with a binding choice treatment. While none of the public good treatments are theoretically incentive compatible, we include a comparison of hypothetical and binding choices for a private-good that is incentive compatible. The private good experiments indicate that marginal willingness to pay (WTP) estimates from the hypothetical treatment are larger, but not statistically different than corresponding estimates in the binding choice treatment. Results for the public good experiments indicate that marginal WTP estimates from the hypothetical treatments are much larger, and statistically different than corresponding estimates in the binding choice treatment. The bias is largest when no provision rule is discussed. The bias is reduced with the inclusion of a provision rule, but surprisingly, there was no difference across provision rule treatments. Overall, our results indicate that choice experiments involving a public good should include a provision rule to reduce bias, but the resulting marginal WTP estimates may still be more biased, on average, than those arising from contingent valuation survey formats.