111 research outputs found
Destination Choice Models for Rock Climbing in the Northeast Alps: A Latent-Class Approach Based on Intensity of Participation
Practitioners of outdoor sports, such as rock-climbers, are likely to exhibit preference heterogeneity that depends on the âkeennessâ with which such sports are practiced. Such an intuition is born out in at least one study using latent class discrete choice modelling (Provencher et al. 2002). Preference heterogeneity has a reflection on the populationâs structure of recreational values assigned to rock-climbing destinations, to their attributes and ultimately to land management policies addressing such attributes. In this study such hypothesis is tested on a panel of destination choices by a sample of rock-climbers members of the Veneto Chapter of the Italian Alpine Club. Preliminary estimates of latent-class (finite-mixing) specifications provided evidence that intensity of participation explained heterogeneity in taste. This motivated our splitting of the sample in a âhighâ and a âlowâ intensity of participation sub-samples, each of which is in turn analysed for the presence of endogenous preference classes using latent-class random utility based approaches. We find evidence in support of the hypothesis that there are at least four statistically well-defined classes in each sub-sample, thereby revealing a considerable richness in the structure of preference, which would otherwise be unobservable in more conventional approaches. From the model estimates, we first focus on the derivation of posterior individual specific welfare measures for some key destination attributes, and then for a welfare neutral land management policy. One emerging feature is the strong evidence of multi-modal distribution of values, a feature that is more difficult to capture when preference heterogeneity is modelled by other means. The results also show how the proposed policy is progressive in terms of benefit distribution in the sample, and that the distribution of individual welfare changes shows markedly different patterns between high and low demand sub-samples.Travel cost model, Preference heterogeneity, Non-market valuation, Random utility model, Latent class analysis, Rock-climbing, Destination choice modelling
Utility in WTP space: a tool to address confounding random scale effects in destination choice to the Alps
Destination choice models with individual-specific taste variation have become the presumptive analytical approach in applied nonmarket valuation. Under the usual specification, tastes are represented by coefficients of site attributes that enter utility, and the distribution of these coefficients is estimated. The distribution of willingness-to-pay (WTP) for site attributes is then derived from the estimated distribution of coefficients. Though conceptually appealing this procedure often results in untenable distributions of willingness to pay. An alternative procedure is to estimate the distribution of willingness to pay directly, through a re-parameterization of the model. We compare hierarchical Bayes and maximum simulated likelihood estimates under both approaches, using data on site choice in the Alps. We find that models parameterized in terms of WTP provide more reasonable estimates for the distribution of WTP, and also fit the data better than models parameterized in terms of attribute coefficients. This approach to parameterizing utility is hence deemed promising for applied nonmarket valuation
The value of collective reputation for environmentally-friendly production methods: The case of Val di Gresta
In this paper we investigate consumers' preferences for various environment-friendly production systems for carrots. We use discrete-choice multi-attribute stated-preference data to explore the effect of collective reputations from growers of an Alpine valley known for its environment-friendly production: Val di Gresta 'the valley of organic orchards'. Data analysis of the panel of discrete responses identifies unobserved taste heterogeneity for organic, bio-dynamic and place of origin, while observed heterogeneity for income is addressed by a piece-wise linear function. The implied sample distributions of individual-specific WTP for each of these random attributes are then compared. Results indicate that Integrated Pest Management is preferred to biodynamic as an emerging method. The presence of a premium for Val di Gresta produce is confirmed. The use of an experimental design to identify the relevant second order effects reveals the presence of a reputation effect which can be decomposed into a generic effect from place of origin and a specific one for each EFPMs. Farmers operating in geographically limited marginal areas, such as mountain valleys, may find it useful to invest in collective reputation through high quality standard to achieve higher returns. This strategy may compensate for the dwindling public support to farm income from EU programmes
Consumer's WTP for Environment-Friendly Production Methods and Collective Reputation for Place of Origin: The Case of Val di Gresta's Carrots
This paper investigates preferences for various environment-friendly production system for carrots using discretechoice multi-attribute stated-preference data amongst buyers and explore the effect of collective reputations from growers of an Alpine valley known to be completely dedicated to organic production. Results show that buyers distinctly recognize only organic production as a production system different from the conventional one, and there is some evidence of recognition of collective reputation. As well as for marginal utility of income, substantial unobserved heterogeneity is found for many skin imperfections, origin from the organic Alpine valley and the organic production methods. The implied sample distributions of WTP for each of these random attributes are then compared.Choice modelling, mixed logit, organic products, marginal utility of income, unobserved taste heterogeneity, status-quo bias, heteroskedasticity, Crop Production/Industries, Environmental Economics and Policy, C15, C25, Q13, Q18,
Destination Choice Models for Rock Climbing in the Northeast Alps: A Latent-Class Approach Based on Intensity of Participation
Practitioners of outdoor sports, such as rock-climbers, are likely to exhibit preference heterogeneity that depends on the keenness' with which such sports are practiced. Such an intuition is born out in at least one study using latent class discrete choice modelling (Provencher et al. 2002). Preference heterogeneity has a reflection on the population's structure of recreational values assigned to rock-climbing destinations, to their attributes and ultimately to land management policies addressing such attributes. In this study such hypothesis is tested on a panel of destination choices by a sample of rock-climbers members of the Veneto Chapter of the Italian Alpine Club. Preliminary estimates of latent-class (finite-mixing) specifications provided evidence that intensity of participation explained heterogeneity in taste. This motivated our splitting of the sample in a high' and a low' intensity of participation sub-samples, each of which is in turn analysed for the presence of endogenous preference classes using latent-class random utility based approaches. We find evidence in support of the hypothesis that there are at least four statistically well-defined classes in each sub-sample, thereby revealing a considerable richness in the structure of preference, which would otherwise be unobservable in more conventional approaches. From the model estimates, we first focus on the derivation of posterior individual specific welfare measures for some key destination attributes, and then for a welfare neutral land management policy. One emerging feature is the strong evidence of multi-modal distribution of values, a feature that is more difficult to capture when preference heterogeneity is modelled by other means. The results also show how the proposed policy is progressive in terms of benefit distribution in the sample, and that the distribution of individual welfare changes shows markedly different patterns between high and low demand sub-samples
Evidence from Family Studies for Autoimmunity in Arrhythmogenic Right Ventricular Cardiomyopathy: Associations of Circulating Anti-Heart and Anti-Intercalated Disk Autoantibodies with Disease Severity and Family History
Background: Serum anti-heart autoantibodies (AHA) and anti-intercalated disk autoantibodies (AIDA) are autoimmune markers in myocarditis. In arrhythmogenic right ventricular cardiomyopathy (ARVC) myocarditis has been reported. To provide evidence for autoimmunity, we searched for AHA and AIDA in ARVC. Methods: We studied: 42 ARVC probands, 23 male, aged 42, interquartile range (IQR) 33;49, 20 from familial and 22 non-familial pedigrees; 37 clinically affected relatives (AR), 24 male aged 35, IQR 18;46; 96 healthy relatives (HR), 49 male, aged 27, IQR 17;45. Serum AHA and AIDA were tested by indirect immunofluorescence on human myocardium and skeletal muscle in 171 of the 175 ARVC individuals and in controls with: non-inflammatory cardiac disease (NICD) (n=160), ischemic heart failure (IHF) (n=141), normal blood donors (NBD) (n=270). Screening of five desmosomal genes was performed in probands; when a sequence variant was identified, cascade family screening followed, blind to immunological results. Results: AHA frequency was higher (36.8%) in probands, AR (37.8%) and HR (25%) than in NICD (1%), IHF (1%) or NBD (2.5%) (p=0.0001). AIDA frequency was higher in probands (8%, p=0.006), in AR (21.6%, p=0.00001) and in HR (14.6% p=0.00001) than in NICD (3.75%), IHF (2%) or NBD (0.3%). AHA positive status was associated with higher frequency of palpitation (p=0.004), ICD implantation (p=0.021), lower left ventricular ejection fraction (LVEF) (p=0.004), AIDA positive status with both lower RV and LVEF (p=0.027 and p=0.027 respectively). AHA and/or AIDA positive status in the proband and/or at least one of the respective relatives was more common in familial (17/20, 85%) than in sporadic (10/22, 45%) pedigrees (p=0.007). Conclusions: Presence of AHA and AIDA provides evidence of autoimmunity in the majority of familial and in almost half of sporadic ARVC. In probands and in AR these antibodies were associated with disease severity features; longitudinal studies are needed to clarify whether they may predict ARVC development in HR or if they be a result of manifest ARVC
Validity and Reliability
AbstractThis chapter concerns different aspects of validity and reliability of a discrete choice experiment. Firstly, it focuses on three essential concepts for assessing the validity of the welfare estimates obtained in the choice experiment, namely content, construct and criterion validity. Secondly, it discusses how the reliability of the recorded choices can be assessed. It then discusses issues related to model comparison and selection. Finally, it addresses prediction in discrete choice models as a way to assess the quality of a model
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