Stated Choice Methods Research Articles

Analysis of drivers’ preferences toward content and message format of variable message signs during tunnel emergency evacuation: A case study of Niayesh tunnel in Tehran

In the event of an emergency evacuation of a tunnel, variable message signs are one of the tools available to tunnel operators to communicate with tunnel users and play an important role in guiding them. In this study, the primary focus is to determine the most appropriate message for variable message signs in terms of content and format for tunnel emergency evacuations. This study evaluates the responses of drivers to the visual comparison between variable message signs by using stated choice methods. Using a binary logit model, the results indicate that drivers prefer the text message “Turn off the car, exit the tunnel” in two lines on the right side of the sign along with the green image of the emergency exit on the left side. Therefore, it is anticipated that the findings obtained and their application at the time of the tunnel disaster will reduce the likelihood of catastrophic accidents and mitigate their consequences.

Preference for different urban greenscape designs: A choice experiment using virtual environments

Nature in cities serves a multitude of purposes, one of which is that it provides citizens opportunities to recover from stressful daily urban life. Such stress recovering effects of nature can be experienced through urban green, which in urban planning and design contexts can be divided into large natural areas - urban green space - and small scale elements in urban streets: the urban greenscape. The current study aims at finding the extent to which various small scale natural elements in residential streets and their possible configurations influence citizens' preferences for those streets. The research was conducted through an online survey in four cities in the Netherlands (n = 4,956). It used stated choice methods in a virtual environment street design. The method yielded high quality data, indicating that the use of virtual environments and imagery is suitable for stated choice research in the built environment.The results show that especially trees very strongly influence preference, indicating they deserve more attention and space in cities. Grass, which is typically favored by local governments, and vertical green have the smallest effects in residential streets. Furthermore, the concept of greenscape intensity is introduced as the intensities of both the element and the configuration were found to be highly relevant. The results clearly show that the higher either of these intensities, the more likely a respondent will prefer the greenscape design. Furthermore, low intensity on the one can be compensated by high intensity on the other. With these results, urban design professionals and local governments can better trade-off the different aspects of costs versus positive effects of urban greenscape designs.

Hypothetical bias and decision-rule effect in modelling discrete directional choices

IntroductionThis empirical study investigates, in parallel, two key questions in relation with modelling discrete choices. (i) To what extent econometric modelling estimates and predictions derived from responses to hypothetical choice scenarios differ from those of an equivalent realistic choice context (i.e. hypothetical bias)? (ii) To what extent econometric modelling estimates and predictions differ as a result of postulating “regret minimisation” as the decision rule as opposed to the “utility maximisation” assumption (i.e. decision-rule effect)? The magnitude of these two effects are also compared relatively. MethodsWe explore the two aforementioned problems in the context of discrete directional choices. Disaggregate experimental observations are collected from both stated-choice (SC) and realistic (or experimentally revealed) choice (RC) settings. We perform our analyses on the basis of four distinct criteria: parameter estimates, parameter ratios, predictions and prediction errors (in terms of disaggregate (i.e. individual-level) choice probabilities)). Results(i) Our results displayed a great degree of resemblance between the parameter estimate patterns emerged from both data sources including a perfect match between the sign and significance of the SC and RC estimates. Major observed discrepancies, however, were related to the scale of the estimates as well as certain coefficient ratios. In terms of the predictions (i.e. simulated probabilities) and prediction errors (i.e. based on a hold-out part of the sample), SC-based models performed surprisingly similar to those of their RC-based counterparts. (ii) The assumption of the decision rule made even a much less noticeable modelling difference (compared to the hypothetical bias) in both parameter estimates and predictions. The shift from utility to regret model led to only marginal differences in estimates, simulated probabilities and prediction errors. Compared to the hypothetical bias in particular, decision-rule specification was a much less impactful modelling component. ApplicationsThese findings contribute to the accumulation of the empirical evidence that can determine how and when one can make best use of the SC methods which, in essence, demands the creation of links between hypothetical and real data in various contexts of choice. Our results suggested that, at least in certain contexts and applications, choice elicitation outcomes are reasonably consistent between the hypothetical and realistic settings. The findings also add to the existing evidence that point at the virtual neutrality of the discrete-choice modelling outcomes to the use of utility versus regret optimisation assumption as the choice rule. Future directionsThe study also leaves us with the further question of how the observed similarity/dissimilarity patterns (SC versus RC; and regret versus utility) would materialise if aggregate prediction measures are of main concern (as opposed to the use of disaggregate measures). The question has particular bearings on applications in which discrete-choice models are applied to simulate or predict a whole system (i.e. when discrete choice models perform as part of a broader model) as a common practice in transport studies. This question will be investigated in a subsequent work.

The Impact of Subsidies and Charging Facilities on Demand for Electric Vehicles in China

The Chinese government has announced a trial programme to provide for private purchase of new battery-operated electric vehicles (EVs) and for plug-in hybrids in five cities. We investigate the potential impact of these subsidies and charging facilities on demand for EVs, using data from a survey of potential car buyers in China. Building on the understanding of factors and incentives that would likely encourage households to adopt EVs would help to improve policy interventions. Data collection is based on experimental design and stated choice methods through an Internet survey. Choice alternatives include a conventional gasoline, a plug-in hybrid and a pure electrical vehicle. In addition to subsidy and charging facilities, we also investigate the impact of common vehicle attributes such as purchase price, cruising range, refuelling time and the socio-demographic effect. Applying a multinomial logit (MNL) model, we find that subsidies would significantly encourage households to choose a plug-in hybrid or an EV. Compared to pure EVs, people in China are more willing to accept plug-in hybrids at present. Compared to the price factors, charging facilities are less of a concern when households consider the adoption of an EV. Willingness-to-pay and market share simulation are computed based on the estimated parameters for further analysis.

Using a multidimensional unfolding approach to assess multiple sclerosis patient preferences for disease-modifying therapy: a pilot study.

PurposeMultidimensional unfolding is a multivariate method to assess preferences using a small sample size, a geometric model locating individuals and alternatives as points in a joint space. The objective was to evaluate relapsing–remitting multiple sclerosis (RRMS) patient preferences toward key disease-modifying therapy (DMT) attributes using multidimensional unfolding.Patients and methodsA cross-sectional pilot study in RRMS patients was conducted. Drug attributes included relapse prevention, disease progression prevention, side-effect risk and route and schedule of administration. Assessment of preferences was performed through a five-card game. Patients were asked to value attributes from 1 (most preferred) to 5 (least preferred).ResultsA total of 37 patients were included; the mean age was 38.6 years, and 78.4% were female. Disease progression prevention was the most important factor (51.4%), followed by relapse prevention (40.5%). The frequency of administration had the lowest preference rating for 56.8% of patients. Finally, 19.6% valued the side-effect risk attribute as having low/very low importance.ConclusionPatients’ perspective for DMT attributes may provide valuable information to facilitate shared decision-making. Efficacy attributes were the most important drug characteristics for RRMS patients. Multidimensional unfolding seems to be a feasible approach to assess preferences in multiple sclerosis patients. Further elicitation studies using multidimensional unfolding with other stated choice methods are necessary to confirm these findings.

How do we densify and socially integrate our cities?: On the efficiency of urban property incentives in the vicinity of mass transit stations

Stated choice methods was used to quantify the effects of different types of incentives (direct, indirect, changes in building regulations, etc.) in the willingness to increase density and reduce social segregation through residential projects in the vicinity of mass transit stations. A sample of 52 professionals from building companies and real-estate firms was asked to evaluate a series of urban scenarios under various incentive schemes and choose, in each case, when would they be prepared to start a conventional residential project (i.e. for buyers belonging to the same socio-economic group) or a socially integrated one (i.e. mixing buyers from different socio-economic groups). Results show that at an aggregate level, only 16% of developers would be interested in starting new residential projects at those locations. However, the availability of incentives could have a significant impact in the willingness to initiate increased density projects around the stations and also, but to a smaller degree, in the willingness to initiate mixed-housing projects.

Stated and revealed exit choices of pedestrian crowd evacuees

IntroductionUnderstanding fundamental behavioural features regulating the escape wayfinding decisions of pedestrian humans in built environments has major implications for the safety planning and the risk-analysis of crowded public facilities. In contrast to the vast interest invested in modelling the momentary responses of evacuees to their immediate surroundings (i.e. the collision-avoidance models), their global navigation behaviour is poorly understood albeit believed to be a major determinant of the accuracy of the crowd simulation models. The primary challenge arises from the scarcity of reliable data suitable for modelling purposes causing the experimental knowledge in the field lagging substantially behind the corresponding model developments. Observations derived from fully natural emergency contexts (in the form of modelling material) are rare and collecting data in realistic experimental settings poses its own major challenges. Only few experimental modelling attempts have been reported thus far in relation with this problem primarily using the stated-choice (SC) methods. Modelling based on revealed choices (RC), however, has remained absent in this context leaving the findings of the SC experiments mostly unverified. It is still unclear whether we can reliably learn from the wayfinding choices made in virtually visualised environments without the decision-makers interacting with real individuals and the physical elements of the environment as they do in the real-world settings. Furthermore, the extent to which the findings of these experiments are specific to the particular characteristics of the environment visualised in the experiments is also unclear. MethodsTo bridge this gap, here we report on discrete-choice estimates derived from observations of both types. Three datasets of stated exit choices (4958 observations) were collected through face-to-face interviews with pedestrians in three public places with the experiments referring to the particular geometry of the place in which the participants were interviewed. Also, 3015 disaggregate real (or more precisely, “realistic”) exit choices were extracted through individual-level video analysis of the footage of a series of novel evacuation trials that simulate pedestrians’ emergency escape. The participants competed and interacted with real individuals in an actual crowd and made actual wayfinding decisions to make the quickest possible escape. Our particular interest was investigating the sample-to-sample variations and the context-dependence of the inferred estimates. ResultsWe observed fairly similar parameter estimate patterns emerged from all four datasets, and identified many behavioural aspects upon which all models consistently agreed regardless of their context of origin. Moreover, despite the significant differences between the parameter scales of the four models, the SC-generated models made predictions that were reasonably similar to those of the RC model as well as to those of the model derived from the combined data. ApplicationsOur findings provide promising evidence as to the potential applicability of the SC methods in particular as well as other forms of virtual-reality decision experiments in general as a practical, flexible and ethical approach for the continuation of research and advancing the state of knowledge in this field.

Crowding cost estimation with large scale smart card and vehicle location data

Crowding discomfort is an external cost of public transport trips imposed on fellow passengers that has to be measured in order to derive optimal supply-side decisions. This paper presents a comprehensive method to estimate the user cost of crowding in terms of the equivalent travel time loss, in a revealed preference route choice framework. Using automated demand and train location data we control for fluctuations in crowding conditions on the entire length of a metro journey, including variations in the density of standing passengers and the probability of finding a seat. The estimated standing penalty is 26.5% of the uncrowded value of in-vehicle travel time. An additional passenger per square metre on average adds 11.9% to the travel time multiplier. These results are in line with earlier revealed preference values, and suggest that stated choice methods may overestimate the user cost of crowding. As a side-product, and an important input of the route choice analysis, we derive a novel passenger-to-train assignment method to recover the daily crowding and standing probability pattern in the metro network.

Motivations and attitudes influence farmers' willingness to participate in biodiversity conservation contracts

Increasingly, voluntary conservation programs are targeted at farmers to contribute to biodiversity conservation through tailored on-farm conservation activities. Such programs are part of a growing suite of agri-environmental or payment-for-environmental services schemes, which can be an effective and efficient way of complementing the formal nature reserve system, provided they attract sufficient participation. In countries with little or no experience with such schemes there is an absence of observable participation behaviour and the use of stated choice methods is required to inform program design. This research employs the theory of planned behaviour to help explain attitudinal and motivational influences on farmers' choices to participate in conservation contracts. The paper reports the findings of a choice experiment involving farmers – more specifically pastoralists and graziers – across north Australia's rangelands. The experiment gauged their willingness to participate in conservation contracts and estimated the influence of contract attributes, business characteristics and personal aspects. Personal aspects included motivations and attitudes, for which constructs were derived from Likert-type scales through factor analysis. Latent class modelling was used to illustrate the various influences of motivations, attitudes and preferences on stated contract participation. The findings assist in tailoring the design, negotiation and roll-out of PES-style conservation initiatives for farmers in northern Australia to incentivise participation. The research highlights the opportunity for paid-for private conservation on parts of large pastoral stations and the need for contract tailoring to biodiversity requirements while responding to the motivations and attitudes of landholders and land managers. It also emphasises the key role that suasion measures play in shaping biodiversity-relevant attitudes and consequently participation by landholders in private conservation.

The Value of a Statistical Life in a Road Safety Context — A Review of the Current Literature

This paper summarizes the state-of-the-art for assessing the value of a statistical life (VSL) as a component of the costs of road accidents. It focuses on the most popular approaches for assessing the VSL, with respect to its theoretical foundations, current state-of-research and empirical evidence. Our paper also provides a first (to our knowledge) compendium of results for the VSL based on Stated Choice (SC) methods. Among the analysed alternatives, the willingness-to-pay (WTP) appears to be the leading approach for assessing the VSL and the SC methods represent the current state-of-the-art for determining the WTP for non-market goods. We conclude that the SC approach overcomes some of the most important shortcomings of the alternative approaches and offers a significant flexibility that can be used to address its own limitations. We also identify a significant need for research, as a gap between the methods employed in research (SC methods) and the state-of-the-practice (other methods) has emerged.

Perbandingan Nilai Kesediaan Membayar Menggunakan Pendekatan Stated Preference Contingent Valuation Dan Stated Preference Stated Choice

Stated Preference method is a flexible non-market valuation method, which is widely used in the cost-benefit analysis. In this study, the willingness to pay for passenger cars is estimated and compared using two different Stated Preference methods, namely the Contingent Valuation and Stated Choice methods. These models are applied to estimate the non-market value of road safety in the City of Bandung. Interviews were conducted with more than 500 residents of the City of Bandung. The results showed that the willingness to pay using contingent valuation method is Rp 180.32/km and willingness to pay using stated choice method is Rp 333.7/km. The main concern for these models is the reliability and validity of the assessment results, because there is a hypothetical question and a big gap between the two models. Therefore the reliability examination for both models is the most significant problem.

Modeling Pedestrian Crowd Exit Choice through Combining Sources of Stated Preference Data

One crucial aspect of pedestrian behavior when a facility is being evacuated is exit selection. This phenomenon, however, is difficult to capture. Recording revealed choices as the exact situations or moments in which individuals make or change their subconscious exit decisions when evacuating a place is highly ambiguous. The approach in which stated choice data are collected offers an appealing solution to tackle the problem. For the underlying factors that influence people's exit decisions to be examined, two types of stated preference (SP) data were collected and pooled: traditional stated preference data and stated preference–off–revealed preference (RP) data. The latter is from the state-of-the-art class of stated choice methods that design experiments with reference to an alternative in an individual's actual choice set. The nested logit trick model and a customized version of the generalized mixed multinomial logit model were applied to estimate the difference in variance scale of the two sectors of data and to quantify the relative contribution of the factors of distance, density, visibility, and herding behavior to exit decisions. Results showed that the SP-off-RP method, compared with the classical SP method, led to lower variance for random noise by a small margin. Compared with the nested logit trick method, the generalized mixed multinomial logit approach allowed researchers to consider more behavioral dimensions of the problem as well as accommodate the difference in scale of variance, including heterogeneity in utility weights and utility scale of individuals, correlation between alternatives, correlation of unobserved utility factors over time, and correlation between utility coefficients.

What residents value in low-cost housing schemes: some South African concepts

What are the significant design aspects of low-cost housing from a value analysis perspective? South Africa has made housing a cornerstone of its social development policies, but there is significant dissatisfaction expressed by the residents of the housing schemes built to date. To address this, a small survey was undertaken to identify what established (existing) residents of low-cost housing in South Africa regard as important or of value. These established residents’ views vary from other studies due to the ability to identify medium and long-term needs and problems. The survey identified nine concepts that can be used to evaluate housing scheme design using conjoint analysis or stated choice methods to quantify residents’ values. Future quantitative research is suggested into the measurement of the requirements of residents. Development of econometric models of the already investigated urban form is advocated, along with the potential for ‘densification’ strategies to address some of the issues raised by residents. Quels sont les aspects importants de la conception de logements sociaux du point de vue de l'analyse de la valeur? L'Afrique du Sud a fait du logement une pierre angulaire de ses politiques de développement social, mais il existe un important mécontentement exprimé par les résidents des ensembles d'habitation construits à ce jour. Afin d'y remédier, il a été entrepris une petite enquête d'opinion visant à identifier ce que les résidents établis (existants) des logements sociaux d'Afrique du Sud considèrent comme important ou ayant de la valeur. Les avis de ces résidents établis diffèrent des autres études en raison de la capacité à identifier les besoins et les problèmes à moyen et long terme. L’étude a identifié neuf concepts qui peuvent être utilisés pour évaluer la conception des ensembles d'habitation en faisant appel à des méthodes d'analyse conjointe ou des méthodes des préférences déclarées pour quantifier les valeurs des résidents. Des recherches quantitatives ultérieures sont suggérées pour mesurer les exigences des résidents. Il est préconisé de développer des modèles économétriques de la forme urbaine déjà étudiée, ainsi que le potentiel des stratégies de « densification » pour faire face à certains des problèmes soulevés par les résidents. Mots clés: logement habitants logements sociaux qualité de la vie développement social gestion de la valeur Afrique du Sud

WHAT DRIVES THE CHOICE OF A THIRD-PARTY LOGISTICS PROVIDER?

It is generally believed that companies choose supply chain partners on the basis of their distinctive value propositions — a fact one would also expect holds true when companies choose a logistics service provider. However, faced with the complexities of varied customer demands, it can be difficult for logistics service companies to obtain an effective understanding of how customers differentially value the service components they offer. In this paper, we address this issue by identifying the factors that are important in a customer's choice of a logistics service provider. Using stated choice methods we explore the relative importance of seven service attributes using a sample of 309 managers with a central role in purchasing logistics services across a range of industries and countries. The results reveal that three distinct decision models populate our data where the preferences for different logistics service attributes — such as price and delivery performance — vary greatly between customer groups represented by these models. Strategically, our findings provide the management of a third‐party logistics provider with a logical starting point from which to determine the goals that are set for their operations, particularly in choosing the customer segments to service.

Numerical Analysis of the Statistical Properties of Uniform Design in Stated Choice Modelling

Stated choice methods have been widely used in transportation studies since 1980s. In recent years, much research attention has been paid to develop optimal or efficient designs for choice experiments, such as the so‐called D‐optimal design, which does not seek for orthogonality as the traditional approach does but aims at minimizing the determinant of the variance–covariance matrix of the parameter estimators. This paper examines the statistical properties of an alternative design method—uniform design, which also does not look for orthogonality but aims at maximizing uniformity—a measure that is closely related to model efficiency. We compare the estimation efficiency and prediction efficiency of uniform design with that of the traditional fractional factorial orthogonal design in stated choice modelling. Monte Carlo experiments are used to generate models, whose parameters vary in scale. The results show that though uniform design uses a lot fewer profiles than orthogonal designs do, its prediction and estimation efficiencies in stated choice modelling are comparable to that of orthogonal design.

Survey-Design and Analytical Strategies for Better Healthcare Stated-Choice Studies

Stated-choice (SC) surveys, such as conjoint analysis, present some interesting problems for researchers that are not addressed in the traditional survey-development literature. While the constraints imposed by preference theory, the experimental design of the choice sets, and the statistical methods used to analyze choice data all pose challenges for researchers new to SC methods, they also direct such researchers towards techniques that are not possible with more traditional survey methods. In this article, we focus on issues of preference heterogeneity (variation in preferences across subjects by observable and non-observable co-variates) and attribute dominance to illustrate the synergistic roles that survey-design and analytical strategies play in SC research. In this article, we show how advanced analytical techniques are likely to be more important than survey-design solutions when addressing preference heterogeneity. Good practice supports the use of mixed-logit and similar modeling approaches to mitigate the problem of unobserved preference or variance heterogeneity. However, if the sample size is not large enough or the survey instrument does not contain questions about important subject characteristics, then the source of heterogeneity cannot be identified and the problems caused by heterogeneity will be magnified.In contrast, minimizing attribute dominance and testing for attribute dominance relies on careful survey design, rather than more complex analysis. In general, survey design needs careful attention from researchers. No amount of complex analysis can compensate for a poor survey design that can generate only flawed SC data.

What Drives the Choice of Third Party Logistics Provider?

It is generally believed that companies choose supply chain partners on the basis of their distinctive value propositions; a fact one would also expect holds true when companies choose a logistics service provider. However, faced with the complexities of varied customer demands, it can be difficult for logistics service companies to obtain an effective understanding of how customers differentially value the service components they offer. In this paper, we address this by identifying the factors that are important in a customer’s choice of a logistics service provider. Using stated choice methods we explore the relative importance of seven service attributes using a sample of 309 managers with a central role in purchasing logistics services across a range of industries and countries. The results reveal that three distinct decision models populate our data where the preferences for different logistics service attributes – such as price and delivery performance –vary greatly between customer groups represented by these models. Strategically, our findings provide the management of a third party logistics provider with a logical starting point from which to determine the goals that are set for their operations, particularly in choosing the customer segments to service.

Extending stated choice analysis to recognise agent-specific attribute endogeneity in bilateral group negotiation and choice: a think piece

This paper is a think piece on variations in the structure of stated preference studies when modelling the joint preferences of interacting agents who have the power to influence the attribute levels on offer. The approach proposed is an extension of standard stated choice methods, known as 'stated endogenous attribute level' (SEAL) analysis. It allows for interactive agents to adjust attribute levels off a base stated choice specification that are within their control, in an effort to reach agreement in an experimental setting. This accomplishes three goals: (1) the ability to place respondents in an environment that more closely matches interactive settings in which some attribute levels are endogenous to a specific agent, should the modeller wish to capture such behaviour; (2) the improved ability of the modeller to capture the behaviour in such settings, including a greater wealth of information on the related interaction processes, rather than simply outcomes; and (3) the expansion of the set of situations that the modeller can investigate using experimental data.

Household demand and willingness to pay for clean vehicles

This paper examines the factors and incentives that are most likely to influence households’ choice for cleaner vehicles in the metropolitan area of Hamilton, Canada. Data collection is based on experimental design and stated choice methods through an Internet survey. Choice alternatives included a conventional gasoline, a hybrid and an alternative fuelled vehicle. Each option is described by a varying set of vehicle attributes and economic incentives, customized per respondent. Controlling for individual, household and dwelling-location characteristics, parameters of a nested logit model indicates that reduced monetary costs, purchase tax relieves and low emissions rates would encourage households to adopt a cleaner vehicle. On the other hand, incentives such as free parking and permission to drive on high occupancy vehicle lanes with one person in the car were not significant. Furthermore, limited fuel availability is a concern when households considered the adoption of an alternative fuelled vehicle. Finally, willingness-to-pay extra for a cleaner vehicle is computed based on the estimated parameters.

Stated Preference and the Estimation of Environmental Values

This paper reviews some of the principal issues involved in deriving accurate estimates of the value of environmental goods using stated choice methods. These encompass embedding and scope effects, and whether to value goods independently, sequentially, or simultaneously. Other issues concern the type of contingent valuation elicitation format to adopt. If the purpose of the study to value attributes of an environmental good, as well as the value of the good as a whole, then a stated choice experiment provides a more appropriate method. The paper also discusses the accuracy of stated preference results.