Should Reference Alternatives in Pivot Design SC Surveys be Treated Differently?

Analysts are increasingly making use of pivot style Stated Choice (SC) data in the estimation of choice models. These datasets often contain a reference alternative whose attributes remain invariant across replications for the same respondent. This paper presents evidence to suggest that respondents react differently to the attributes of these reference alternatives and those of purely hypothetical alternatives. While some such evidence has been reported in the existing literature, this paper goes further and details a number of different departures from a common treatment of the two types of alternatives, relating both to the observed part of utility and the error term.     

Testing for rationality: the case of discrete choice data

When working with micro data on consumer demand, there are many different situations where decisions involve only discrete choices. In this context, conditions under which an underlying rational preference structure exists are derived. Moreover, by introducing flexibility into the model, it is possible to identify nonrational behavior in the sample.     

Unanimous subjective probabilities

This note shows that if the space of events is sufficiently rich and the subjective probability function of each individual is non-atomic, then there is a σ-algebra of events over which everyone will have the same probability function, and moreover, the range of this common probability is the entire unit interval.      

Almost-objective uncertainty

Summary. Every subjective state space with Euclidean structure contains almost-objective events which arbitrarily closely approximate the properties of objectively uncertain events for all individuals with event-smooth betting preferences - whether or not they are expected utility, state-independent, or probabilistically sophisticated. These properties include unanimously agreed-upon revealed likelihoods, statistical independence from other subjective events, probabilistic sophistication over almost-objective bets, and linearity of state-independent and state-dependent expected utility in almost-objective likelihoods and mixtures. Most physical randomization devices are based on events of this form. Even in the presence of state-dependence, ambiguity, and ambiguity aversion, an individuals betting preferences over almost-objective events are based solely on their attitudes toward objective risk, and can fully predict (or be predicted from) their behavior in an idealized casino.Received: 17 July 2003, Revised: 12 November 2003, JEL Classification Numbers: D81.I am grateful to Kenneth Arrow, Erik Balder, Hoyt Bleakley, Richard Carson, Eddie Dekel, Larry Epstein, Clive Granger, Simon Grant, Peter Hammond, Jean-Yves Jaffray, Edi Karni, Peter Klibanoff, Duncan Luce, John Pratt, Chris Tyson, Uzi Segal, Peter Wakker, Joel Watson, Nicholas Yannelis, anonymous referees and especially Ted Groves and Joel Sobel for helpful comments. This material is based upon work supported by the National Science Foundation under Grant No. 9870894.     

Ecosystem services value of wetland in Suzhou Taihu Lake

Based on a comprehensive analysis on various classifications of natural resource values,this paper summarizes an ecological services system of constructed wetland（CW） ecosystems for the accounting of ecological economic value.With the research,the wetland ecosystem services can be classified into six categories,that is waste treatment,food and material production,water supply,gas regulations,disturbance and water regulations,habitat and refuge provision.For decision making in terms of environmental economics for wetland construction,ecosystem services value for the wetland in Suzhou Taihu Lake National Tourist and Holiday Resort is accounted for 7,088,769 USD/yr through Environmental Economics Analysis.Ecosystem services value of waste treatment is 825,000 USD/yr,that of food and material production is 1,430 USD/yr,that of water supply is 4,752,000 USD/yr,that of gas regulation is 2,251USD/yr,that of disturbance and water regulations is 1,3721 USD/yr,and that of habitat and refuge provision value is 1,494,367 USD/yr.The ecosystem services values of a pilot constructed wetland in Suzhou are compared with those of other wetlands as a mean and of a typical human-interfered wetland in Wenzhou of China.Results show that in both finite and infinite time horizons considered,the wetland in Suzhou Taihu Lake National Tourist and Holiday Resort has the largest services value.This paper analyzes all the probability that may weaken the value of the Suzhou Taihu Wetland in order to provide some advices for the wetland protection.     

A discrete choice experiment to determine patient preferences for injection devices in multiple sclerosis

Abstract

Objective:

Relapsing-remitting multiple sclerosis (MS) is usually managed with disease modifying drugs (DMDs), most commonly administered via self-injection. The aim of this study was to estimate the influence that different treatment-related attributes have for MS patients on their choice of MS DMD device. By establishing the relative importance of these characteristics for patients it should be possible to better understand the acceptability of a given device and to optimize the development of future devices.

Methods:

A discrete choice experiment (DCE) survey was developed on the basis of a review of published literature. Attributes identified for inclusion in the survey were: ease of use; comfort of use; presence of additional functions, needle visibility; practicality and efficacy. Choice sets were presented as pairs of hypothetical treatments based upon a fractional factorial design. One-hundred device-using MS patients completed the survey online. Analysis was conducted using a mixed-logit approach.

Results:

Analysis of the DCE data revealed that all attributes significantly predicted treatment choice. Efficacy exhibited the largest effect on treatment selection and this provided context for understanding the magnitude of impact for the other attributes. Reducing the discomfort associated with device use and eliminating the necessity for assembly or drug reconstitution were highly valued. The addition of reminder and time-stamping functions, improved needlestick injury prevention, and reduction in device size were secondary concerns but still deemed desirable.

Conclusion:

Efficacy is of primary importance to MS patients, but characteristics of drug delivery devices can play an important role in treatment decision-making. Not all device characteristics could be included, and results are based upon 100 participants only. Findings suggest there is significant potential value in developing self-injection devices that are not only efficacious but also convenient and comfortable to use. Reducing barriers to adherence could potentially translate into improved treatment outcomes for patients with MS.     

‘Expected utility / subjective probability’ analysis without the sure-thing principle or probabilistic sophistication

Summary. The basic analytical concepts, tools and results of the classical expected utility/subjective probability model of risk preferences and beliefs under subjective uncertainty can be extended to general event-smooth preferences over subjective acts that do not necessarily satisfy either of the key behavioral assumptions of the classical model, namely the Sure-Thing Principle or the Hypothesis of Probabilistic Sophistication. This is accomplished by a technique analogous to that used by Machina (1982) and others to generalize expected utility analysis under objective uncertainty, combined with an event-theoretic approach to the classical model and the use of a special class of subjective events, acts and mixtures that exhibit almost-objective like properties. The classical expected utility/subjective probability characterizations of outcome monotonicity, outcome derivatives, probabilistic sophistication, comparative and relative subjective likelihood, and comparative risk aversion are all globally robustified to general event-smooth preferences over subjective acts.Received: 4 May 2004, Revised: 4 October 2004, JEL Classification Numbers: D81.This paper presents a considerably improved version of the concept of event-differentiability from Machina (1992). An alternative definition has been independently developed by Epstein (1999) in his analysis of the concept of uncertainty aversion. I am grateful to Kenneth Arrow, Mark Durst, Jürgen Eichberger, Daniel Ellsberg, Clive Granger, Simon Grant, Edi Karni, Peter Klibanoff, David Kreps, Duncan Luce, Robert Nau, Uzi Segal, Peter Wakker, Joel Watson and especially Larry Epstein, Ted Groves and Joel Sobel for helpful discussions and comments. This material is based upon work supported by the National Science Foundation under Grants No. 9209012 and 9870894.     

Subjective recursive expected utility

We axiomatize a subjective version of the recursive expected utility model. This development extends the seminal results of Kreps and Porteus (Econometrica 46:185–200 (1978)) to a subjective framework and provides foundations that are easy to relate to axioms familiar from timeless models of decision making under uncertainty. Our analysis also clarifies what is needed in going from a represention that applies within a single filtration to an across filtration representation.Part of this research was conducted when Ozdenoren visited MEDS in Fall 2003. We thank Tapas Kundu, Costis Skiadas, Jean-Marc Tallon and Tan Wang for helpful discussions and also thank audiences at Koc University, Northwestern University, the CERMSEM conference “ Mathematical Models in Decision Theory” at Universite Paris I, and the FUR XI conference on foundations and applications of utility, risk and decision theory     

A GIS-based approach for mapping direct use value of ecosystem services at a county scale: Management implications

A GIS-based approach was designed to spatially estimate direct use value of ecosystem services and to map results for a case study at county scale. The approach highlights the use of GIS to collect data, perform spatial analysis, and map economic values of ecosystem services. Three key steps of spatial valuation for agricultural products, forest products, and tourism services were illustrated in the GIS-based technical framework. We applied this approach to the Tiantai County (1423.8 km²) in Zhejiang province of southeast China. Selected components of natural products and tourism services in the case area were mapped as data layers in GIS, with each layer containing monetary values for every 25 m cell. The total direct use value of ecosystem services was estimated in RMB to be approximately 538 million Yuan in 2005 (Chinese currency, 8.2 Yuan = US$1), of which agricultural products, forest products and tourism services accounted for 65%, 30% and 5%, respectively. The critical areas for management purpose were identified depending on the heterogeneity of direct use services learned from the case study. The spatially explicit measures provide a mechanism for incorporating spatial context into ecosystem services evaluation. Based on the present GIS-based approach and case study, the suggestions and implications for local resources protection and eco-environmental management were extensively discussed. The work was expected to highlight research avenues to advance the ecosystem services framework as an operational basis for regional ecosystem-based management.     

A discrete choice experiment to determine UK patient preference for attributes of disease modifying treatments in Multiple Sclerosis

Aims: The recent licensing of Disease Modifying Treatments (DMTs) for Multiple Sclerosis (MS) has increased available treatment options. The aim of this study was to explore MS patients’ preference for the different attributes of DMTs in the UK.

Materials and methods: Attributes (treatment characteristics) for inclusion in the discrete choice experiment (DCE) were determined through published literature and interviews with 12 people with MS. Seven attributes were selected. Participants were presented with three hypothetical treatment options sampled from included attributes and asked for their most/least preferred options. The influence of patient characteristics and demographics on patient preference was also investigated.

Results: The DCE was completed by 350 people with MS (81% female, mean age?=?39). Results showed that method of taking medication was the strongest determinant of preference (27%; relative importance out of 100%), followed by relapse free rate (21%) and symptom progression (14%). Risk of fatigue (8%) and type of monitoring (6%) were the weakest determinants of preference. Once-daily oral treatment was preferred over all other methods of administration. Participant characteristics did not influence data on strength of preference.

Limitations: This study assumed adequate participant understanding of the discrete choice experiment task, and recruitment targeted those with access to the internet.

Conclusions: These results, derived from people with MS in the UK, should be used to inform individual discussions with patients about DMT choices.     

黄河流域水资源生态系统服务价值时空变化及驱动分析——以关中平原城市群为例

黄河流域城市群的发展面临着水资源刚性约束强、跨域治理难度大、承载力不足等问题的严峻挑战。采用环境经济核算方法与水足迹评估了关中平原城市群水资源生态系统服务价值,在描述时空演变特征的基础上揭示了社会经济因素对价值变化的驱动作用。结果表明,生态系统服务价值平稳增长,呈现东南部高于西北部的区域差异特点。价值变化受农业总产值与第二产业生产总值的影响较大,城镇化率、旅游人数等也是主要影响因素。建议把生态系统服务价值纳入到城市水治理中,通过调整城市产业结构与人口密度、推进跨域协同等措施加快绿色转型。本文探索性地编制城市群水资源生态系统账户并进行了核算,为突出生态服务功能在水资源保护与利用提供了科学依据。     

The quantification and valuation of ecosystem services

This paper explores differences between economic and ecological criteria for identifying, measuring, and evaluating ecosystem services. It argues that economic stakeholders (user groups) generally do well in identifying these services and assigning prices to them. These prices arise spontaneously in—and serve to coordinate—market activity related to the environment. The relevant ecological information which markets gather and apply tends to be dispersed, contingent, particular, local, transitory, and embedded in institutions and practices. Ecologists and other scientists, in contrast, often seek to understand how ecosystems work and which populations and processes provide ecosystem services. The knowledge science seeks, unlike the information markets gather, tends to be centralized, collaborative, collective, and consensus-based; science pursues concepts and principles that are timeless and general rather than ephemeral and site-specific. The paper contrasts the dispersed and decentralized information organized by markets with the collective and centralized knowledge characteristic of science. The paper argues that the conceptual distance between market-based and science-based methods of assembling information and applying knowledge defeats efforts to determine the “value” of ecosystem services in any integrated sense.     

Does attribute order influence attribute-information processing in discrete choice experiments?

The existing empirical evidence shows that both contingent valuation and discrete choice experiment (DCE) methods are susceptible to various ordering effects. However, very few studies have analysed attribute-ordering effects in DCEs, and no study has investigated their potential influence on information-processing strategies, such as attribute non-attendance (ANA). This paper tests for attribute-ordering effects and examines whether the order of attributes describing the alternatives affects respondents’ propensity to attend to or ignore an attribute. A split-sample approach is used, where one sample received a DCE version in which the positions of the first and last non-monetary attributes are switched across the sequence of choice tasks compared with the other sample. The results show that attribute order does not affect welfare estimates in a significant way under the standard assumption of full attribute attendance, thus rejecting the notion of procedural bias. However, the welfare estimates for the attributes whose order was reversed and the share of respondents who ignored them differ significantly between the two attribute-ordering treatments once ANA behaviour is accounted for in the estimated choice models. These results highlight the important role of information-processing strategies in the design and evaluation of DCEs.     

A new approach to modeling decision-making under uncertainty

This paper presents two axiomatic models of decision making under uncertainty that avoid the use of a state space. The first is a subjective expected utility model with action-dependent subjective probabilities and effect-dependent preferences (the case of effect-independent preferences is obtained as a special instance). The second is a nonexpected utility model involving well-defined families of action-dependent subjective probabilities on effects and a utility representation that is not necessarily linear in these probabilities (a probabilistic sophistication version of this model, with action-dependent subjective probabilities is obtained as a special case). The hospitality of EUREQua, University of Paris 1, and financial support by the National Science Foundation grant SES-0314249 are gratefully acknowledged.     

Indices of biotic integrity in stated preference valuation of aquatic ecosystem services

Stated preference surveys often give minimal attention to distinctions between intermediate and final ecosystem services, leading to the potential for welfare estimates that overlook, misrepresent or double count associated values. This paper illustrates potential mechanisms through which multimetric indexes of the type developed in the ecological literature, here an index of biotic integrity, can be used within stated preference survey scenarios to both improve the validity of survey responses and provide otherwise unavailable information on willingness to pay for intermediate and final ecosystem services. We illustrate the approach using a choice experiment application to the restoration of migratory fish in a Rhode Island watershed. Where assumptions of the model hold, results can allow transparent disentanglement and estimation of marginal values for both intermediate and final ecosystem services.