Identifying demand parameters in the presence of unobservables: A combined revealed and stated preference approach

• ALTHOUGH MOST ACADEMIC programs use hospital-based sites for perioperative clinical experiences, the exponential growth in the number of ambulatory surgery centers (ASCs) and the increased variety of procedures performed in these settings make ASCs excellent venues for student learning experiences.• NURSING STUDENTS in one program in Florida have the opportunity to take a perioperative practicum designed to allow them to learn about all aspects of patient care and administrative functions in ASCs.• THE ASC PRACTICUM EXPERIENCE is popular with students and staff members alike, and ASC administrators are seeking ways to increase the number of students in the program in an effort to attract new graduates to ASCs. AORN J 84 (August 2006) 219–232. © AORN, Inc, 2006.

Improving multi-site benefit functions via Bayesian model averaging: A new approach to benefit transfer

A benefit function transfer obtains estimates of willingness-to-pay (WTP) for the evaluation of a given policy at a site by combining existing information from different study sites. This has the advantage that more efficient estimates are obtained, but it relies on the assumption that the heterogeneity between sites is appropriately captured in the benefit transfer model. A more expensive alternative to estimate WTP is to analyze only data from the policy site in question while ignoring information from other sites. We make use of the fact that these two choices can be viewed as a model selection problem and extend the set of models to allow for the hypothesis that the benefit function is only applicable to a subset of sites. We show how Bayesian model averaging (BMA) techniques can be used to optimally combine information from all models.The Bayesian algorithm searches for the set of sites that can form the basis for estimating a benefit function and reveals whether such information can be transferred to new sites for which only a small data set is available. We illustrate the method with a sample of 42 forests from U.K. and Ireland. We find that BMA benefit function transfer produces reliable estimates and can increase about 8 times the information content of a small sample when the forest is ‘poolable’.     

上海城市内河生态系统服务的条件价值评估

条件价值评估法(CVM)是估算生态系统服务最主要的技术方法之一。浦东张家浜的综合整治为全国河道整治的样板工程,笔者采用CVM引出张家浜沿线居民对改善张家浜生态系统的平均支付意愿(528 8元 a),初步估算出张家浜综合整治后的生态系统服务价值约为3 014～5 262亿元 a。讨论了导致支付意愿产生偏差的各方面原因,研究了张家浜沿线居民对张家浜整治项目的支付意愿和被调查者收入、年龄、受教育程度等因素的关系。最后提出了CVM研究结果的可靠性和国内在CVM研究中亟待解决的问题。      

Scope effects of respondent uncertainty in contingent valuation: evidence from motorized emission reductions in the city of Nairobi,Kenya

This study analyzed the scope effects of respondent uncertainty in contingent valuation (CV) by evaluating whether willingness to pay (WTP) estimates were sensitive to changes in the magnitudes of motorized emission reductions in the city of Nairobi, Kenya. The WTP estimates were elicited through the conventional payment card (PC), stochastic payment card (SPC) and the polychotomous payment card (PPC) formats. While SPC and PPC formats were used to capture respondent uncertainty, the PC format captured respondent certainty regarding the amounts individuals were WTP for emission reductions. Based on parametric and nonparametric analysis, results show that certain (PC) respondents stated significantly larger WTP amounts for larger emission reductions than for smaller reductions. Conversely, uncertain (SPC and PPC) respondents stated smaller amounts for larger emission reductions than certain (PC) respondents. The implication is that though respondents were sensitive to the scope of motorized emission reductions, respondent uncertainty lowered their sensitivity to scope.     

Social influences on expressed willingness to pay: results of a deliberative monetary valuation study in Colombia

Deliberative monetary valuation (DMV) methods can support environmental decision making by enabling the exchange of arguments and information to produce more democratic outcomes. The product of a valuation may be an array of expressions of willingness to pay (WTP) by individuals or a collectively agreed monetary value. Concerns have been raised, however, as to whether this product is an outcome of thoughtful and independent decision-making or influenced by social pressures to conform. Our study examines this issue and addresses concerns about the use of DMV, based on a public deliberation of forest conservation in Colombia. We analyzed the impacts of social conformity on WTP under two different decision scenarios: individual and collective. The results suggest that the impacts of social conformity are greater when a collective decision is required. These findings indicate that tensions between the differing goals of DMV could undermine its democratic promise.     

Validity of CVM related to the type of environmental good; an empirical test

This research explores the boundaries of a valid application of contingent valuation as a method to value environmental changes. Recent criticism from social psychologists refers to unrealistic cognitive demands upon respondents. Criticism from economists point to the problem of measuring preferences in relation to non-use values. In this research the hypothesis is tested that the CV method in valuing goods with non-use value and with a complex content of information produces less valid results than with use values and non-complex content of information. Validity is tested across goods (sample survey: N=832). Results show that scope validity is ambiguous for goods with high content of complexity. Construct validity is not guaranteed for environmental changes with non-use values: Economic factors are not significant, only attitudes are relevant. Given the importance of WTP figures in cost-benefit analysis these results are of paramount importance for the trust in contingent valuation.     

Bridging the gap between laboratory experiments and naturally occurring markets: An inferred valuation method

Several recent studies have found important differences between behavior in the laboratory and the field. We explore two possible causes for the divergence: social concerns and unfamiliarity with the traded good. Consistent with our conceptual model, we find that people overstated their preferences for relatively familiar goods with normative attributes and understated their preferences for a relatively unfamiliar good with low normative motivations in the laboratory as compared to the field. We also find that for goods with a normative dimension, a new method we refer to as inferred valuation has the potential to narrow the lab–field gap. In some cases, willingness-to-pay obtained from a conventional valuation elicitation method is more than twice the value from the new inferred valuation approach.     

企业自创商誉的确认与计量

按照传统的会计处理模式和惯例,无形资产中可以辨认的专利权、商标权已予确认和计量,而对于商誉,国内会计准则规定,只有在企业并购时,才作为一项无形资产确认入账,即只对外购商誉进行确认和计量,而不确认和计量自创商誉．在新的经济形势下,对于自创商誉应该有新的认识,就对自创商誉的确认和计量问题做出一些论述．参5．     

A Note on Consistent Estimation of Mean WTP Using a Misspecified Logit Contingent Valuation Model

Monte Carlo evidence has shown that simple, misspecified referendum contingent valuation (CV) models sometimes lead to good estimates of mean willingness to pay (WTP). Empirical studies have found that estimates of mean WTP derived from simple parametric models often differ little from those derived from nonparametric methods. This indicates that simple models can potentially yield WTP estimators that are relatively unbiased. This note shows that very simple logit referendum CV models will estimate mean WTP consistently if the survey bids are drawn randomly from a uniform distribution.     

基于游客支付意愿的古树名木资源保护经济价值评估——以安徽省九华山风景区为例

运用条件价值评估法中支付卡式(PC)和二分式(DC)两种问卷,对九华山风景区游客保护古树名木的支付意愿进行研究,并分析了其影响因素。结果表明：838%的游客认为应该对古树名木进行保护,仅有302%对保护现状满意。支付卡式问卷调查结果为808元/(人·月),二分式问卷调查结果为954元/(人·月);按2010年游客接待量401万人次计算,2010年游客对九华山风景区古树名木保护的总支付意愿分别为1500×108元和4589×108元。影响支付卡式问卷支付意愿值的主要指标是年龄、个人年收入、文化程度和职业的相关性;影响二分式问卷支付意愿的主要指标是个人年收入。支付卡式问卷和二分式问卷支付意愿均与第一次调查结果无显著差异,PC1和PC2、DC1和DC2支付意愿值相差分别为062和173元,两次结果重现性良好,对本次研究结果的可靠性给予了保证