Consulta: subjectFacets:"Random parameters"
Registros recuperados: 8
Data/hora: 17/06/2024 14:48:51

What to Choose?  The Value of Label Claims to Fresh Produce Consumers
Provedor de dados: 31
Autores: Bond,   Craig A.; Thilmany,   Dawn D.; Bond,   Jennifer Keeling.
We examine consumer response to label information using a hypothetical choice experiment on red leaf lettuce attribute bundles.  Using survey responses, several mixed logit models with random parameters and varying correlation assumptions are estimated that provide estimated of marginal utilities ( and marginal values) of various attributes related to general health claims, specific nutrition and health claims, certification logos, and certified organic claims (relative to the conventional reference group) for this fresh produce product.  We find that consumers distinguish between labeling claims, and that attribute bundling effects are present, suggesting the results from main effects (linear) models may be misleading.  Furthermore, the results imply that...
Tipo: Journal Article
Palavras-chave: Choice experiment; Conditional distribution; Preference heterogeneity; Produce labels; Random parameters; Food Consumption/Nutrition/Food Safety.
Ano: 2008
URL: http://purl.umn.edu/46559

Determining Optimal Levels of Nitrogen Fertilizer Using Random Parameter Models
Provedor de dados: 31
Autores: Tumusiime,   Emmanuel; Brorsen,   B. Wade; Mosali,   Jagadeesh; Johnson,   Jim; Locke,   James; Biermacher,   Jon T.
The parameters of yield response functions can vary by year. Past studies usually assume yield functions are nstochastic  ‘‘limited’’ stochastic. In this study, we estimate rye– ryegrass yield functions in which all parameters are random. The three functional forms considered are the linear response plateau, the quadratic, and the Spillman-Mitscherlich. Nonstochastic yield models are rejected in favor of stochastic parameter models. Quadratic functional forms fit the data poorly. Optimal nitrogen application recommendations are calculated for the linear response plateau and Spillman-Mitscherlich. The stochastic models lead to smaller recommended levels of nitrogen, but the economic benefits of using fully stochastic crop yield functions are small because...
Tipo: Journal Article
Palavras-chave: Cereal rye–ryegrass; Monte Carlo; Nitrogen; Random parameters; Stochastic plateau; Production Economics; Q10; C12; D24.
Ano: 2011
URL: http://purl.umn.edu/117949

Discrete choice models, which one performs better?
Provedor de dados: 31
Autores: Gallardo,   Rosa Karina; Chang,   Jae Bong.
For over the last thirty years the multinomial logit model has been the standard in choice modeling.  Development in econometrics and computational algorithms has led to the increasing tendency to opt for more flexible models able to depict more realistically choice behavior.  This study compares three discrete choice models, the standard multinomial logit, the error components logit, and the random parameters logit.  Data were obtained from two choice experiments conducted to investigate consumers’ preferences for fresh pears receiving several postharvest treatments. Model comparisons consisted of in-sample and holdout sample evaluations.  Results show that product characteristics hence, datasets, influence model performance. We also found that the...
Tipo: Conference Paper or Presentation
Palavras-chave: Multinomial logit model; Error components; Random parameters; Discrete choice; Research Methods/ Statistical Methods; C25; D12.
Ano: 2010
URL: http://purl.umn.edu/61483

Determining Optimal Levels of Nitrogen Fertilizer Using Random Parameter Models
Provedor de dados: 31
Autores: Tumusiime,   Emmanuel; Brorsen,   B. Wade; Biermacher,   Jon T.; Mosali,   Jagadeesh; Johnson,   Jim; Locke,   James.
The parameters of yield response functions can vary by year. Past studies usually assume yield functions are nonstochastic or ‘limited’ stochastic. In this study, we estimate rye-ryegrass yield functions where all parameters are random. Optimal nitrogen rates are calculated for two yield response functions: linear response plateau and quadratic. Nonstochastic models are rejected in favor of stochastic parameter models. However, the economic benefits of using fully stochastic models are small since optimal nitrogen rates do not differ greatly between stochastic and nonstochastic models.
Tipo: Conference Paper or Presentation
Palavras-chave: Linear response plateau; Monte Carlo; Nitrogen; Random parameters; Agricultural and Food Policy; Crop Production/Industries; Farm Management; Production Economics.
Ano: 2010
URL: http://purl.umn.edu/56514

European Preferences for Beef Steak Attributes
Provedor de dados: 31
Autores: Tonsor,   Glynn T.; Schroeder,   Ted C.; Fox,   John A.; Biere,   Arlo W.
A choice experiment is used to evaluate how consumers in London, Frankfurt, and Paris value beef steaks with attributes such as: "hormone-free," "GM-free," farm-specific source verification, and domestic origin. The effect of various consumer characteristics on steak selection is also evaluated. Results suggest that European consumers are significantly heterogeneous in their preferences for beef steak attributes. French and German consumers have a higher willingness to pay to avoid genetically modified feed use than British consumers, while German and British consumers would pay more for growth hormone-free beef. French and German consumers are willing to pay for farm-specific source verification.
Tipo: Journal Article
Palavras-chave: Beef; Choice experiment; Country of origin; Genetically modified; Hormones; Preference heterogeneity; Random parameters; Source verification; Consumer/Household Economics.
Ano: 2005
URL: http://purl.umn.edu/31213

Preference Heterogeneity in a Count Data Model of Demand for Off-Highway Vehicle Recreation
Provedor de dados: 31
Autores: Holmes,   Thomas P.; Englin,   Jeffrey E.
This paper examines heterogeneity in the preferences for OHV recreation by applying the random parameters Poisson model to a data set of off-highway vehicle (OHV) users at four National Forest sites in North Carolina. The analysis develops estimates of individual consumer surplus and finds that estimates are systematically affected by the random parameter specification. There is also substantial evidence that accounting for individual heterogeneity improves the statistical fit of the models and provides a more informative description of OHV riders.
Tipo: Journal Article
Palavras-chave: Consumer surplus; Off-highway vehicles; Outdoor recreation; Poisson model; Random parameters; Environmental Economics and Policy.
Ano: 2010
URL: http://purl.umn.edu/59334

U.S. Consumers’ Valuation of Quality Attributes in Beef Products
Provedor de dados: 31
Autores: Abidoye,   Babatunde O.; Bulut,   Harun; Lawrence,   John D.; Mennecke,   Brian; Townsend,   Anthony M.
A sample of U.S. consumers were surveyed in a choice based experiment in the Fall of 2005 and Spring 2006 to elicit consumers’ preferences for quality attributes in beef products. Based on the resulting data, a random coefficients logit model is estimated, and consumers’ willingness to pay for these quality attributes in beef products is obtained. The results indicate that consumers have strong valuation for traceability, grass-fed, and U.S. origin attributes in a standard rib-eye steak and are willing to pay a premium for these attributes.
Tipo: Journal Article
Palavras-chave: Choice experiment; Conjoint analysis; Quality attributes; Random parameters; Consumer/Household Economics; Marketing; Q10; Q1.
Ano: 2011
URL: http://purl.umn.edu/100645

Mixed effect models for predicting breast height diameter from stump diameter of Oriental beech in Göldağ
Provedor de dados: 63
Autores: Ercanli,Ilker; Gunlu,Alkan; Başkent,Emin Zeki.
Diameter at breast height (DBH) is the simplest, most common and most important tree dimension in forest inventory and is closely correlated with wood volume, height and biomass. In this study, a number of linear and nonlinear models predicting diameter at breast height from stump diameter were developed and evaluated for Oriental beech (Fagus orientalisLipsky) stands located in the forest region of Ayancık, in the northeast of Turkey. A set of 1,501 pairs of diameter at breast height-stump measurements, originating from 70 sample plots of even-aged Oriental beech stands, were used in this study. About 80 % of the otal data (1,160 trees in 55 sample plots) was used to fit a number of linear and nonlinear model parameters; the remaining 341 trees in 15...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: DBH; Prediction; Random parameters; Calibration.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162015000300245