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Registros recuperados: 13
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An Econometric Analysis of Price Dynamics in the Presence of a Price Floor: The Case of American Cheese AgEcon
Chavas, Jean-Paul; Kim, Kwansoo.
In this paper, we present an econometric analysis for the effects of a price floor on price dynamics and price volatility. A price floor (implemented as a part of government pricing policy) provides a censoring mechanism for price determination. We specify and estimate a dynamic Tobit model under time-varying volatility. The model is applied to analyze the effects of a price support program on price dynamics and price volatility in the U.S. American cheese market. The econometric analysis provides useful insights on price dynamics in the presence of a government-determined price floor.
Tipo: Journal Article Palavras-chave: Censored regression; Market liberalization; Model selection; Price dynamics; Price volatility; Demand and Price Analysis; Q0; D4; C5.
Ano: 2005 URL: http://purl.umn.edu/43628
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Consumer demand for fresh fruit AgEcon
Lee, Jonq-Ying.
Tipo: Report Palavras-chave: Differential demand systems; Model selection; Fresh fruits; Demand and Price Analysis.
Ano: 1995 URL: http://purl.umn.edu/52747
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Demands for Food Products Across the Development Spectrum: Application of a Rank Four Demand System AgEcon
Cranfield, John A.L..
A rational rank four AIDS model (RAIDS) is used to estimate consumer demands for final goods and services in countries spanning the development spectrum. RAIDS is used as it provides more general price and expenditure responses. It also nests the Quadratic and non-liner AIDS models. RAIDS is estimated using the entire sample and sub-samples based on the country's level of per capita expenditure. Results indicate selection of nested functional form differs by sub-sample. AIDS is selected for the low per capita expenditure countries, sample is considered. Differences in parameter estimates manifest themselves in price and Engel elasticities. Such differences warrant caution when using global demand systems to undertake policy analysis.
Tipo: Working or Discussion Paper Palavras-chave: Consumer demand; Model selection; Demand system rank; Demand and Price Analysis.
Ano: 2005 URL: http://purl.umn.edu/34111
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Evaluation of Bayesian models for analysis of crude protein requirement for pigs of Brazilian Piau breed Scientia Agricola
Silva,Hugo Teixeira; Silva,Fabyano Fonseca e; Ferreira,Aloízio Soares; Veroneze,Renata; Lopes,Paulo Sávio.
ABSTRACT: We evaluated the inclusion of information on genetic relationship into the analysis of crude protein requirement in diets for pigs of Brazilian Piau breed, using Bayesian inference. The animals were assigned to treatments in a completely randomized design in factorial scheme 4 × 2 (crude protein levels × sex) with 12 repetitions per treatment. The evaluations were carried out in the initial, growing and finishing phases, and after slaughter. The traits evaluated were feed conversion (FC), backfat thickness (BF), daily weight gain (DWG), daily feed intake (DFI) and some carcass cuts. Three models were considered to evaluate the inclusion of information on genetic relationship into the analysis: Model I, a simple linear model; Model II, the same...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Bayesian inference; Genetic relationship; Model selection; Performance.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162019001300208
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Habitats of ten demersal species in the Gulf of Lions and potential implications for spatial management ArchiMer
Morfin, Marie; Bez, Nicolas; Fromentin, Jean-marc.
An improved knowledge of habitat utilization by demersal species is a pre-requisite for their spatial management. Based on scientific survey data collected over the period 1994-2010, the present study investigates relationships between 4 environmental factors and 10 demersal species in the Gulf of Lions (northwestern Mediterranean Sea). Generalized linear models provided statistically satisfying results in terms of both model explanatory and predictive powers. The 'biological zone' factors, based on the percentage of light penetration to the sea bottom and bottom temperature, were the most important factors, while sediments and benthic macrofauna were only significant for a few species. The type of associations varied among species, resulting in different...
Tipo: Text Palavras-chave: Fish habitat; Marine living resources; Mediterranean; Generalized linear models; Model selection; Marine Protected Area; MARXAN.
Ano: 2016 URL: http://archimer.ifremer.fr/doc/00334/44502/45846.pdf
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Linking Land Change with Driving Forces and Actors: Four Conceptual Models Ecology and Society
Hersperger, Anna M.; Land Use Dynamics Unit, Swiss Federal Research Institute WSL; anna.hersperger@wsl.ch; Gennaio, Maria-Pia; Swiss Federal Research Institute Agroscope ART; maria.gennaio@art.admin.ch; Verburg, Peter H.; Institute for Environmental Studies, VU University Amsterdam ; peter.verburg@ivm.vu.nl.
Tipo: Peer-Reviewed Reports Palavras-chave: Conceptualization; Guidelines; Land change modeling; Land cover change; Land use; Model selection; Organizational heuristic.
Ano: 2010
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MEAT DEMAND IN THE UK: A DIFFERENTIAL APPROACH AgEcon
Fousekis, Panos; Revell, Brian J..
A differential approach is employed to analyze demand for meat in the United Kingdom during 1989-99. Differential demand systems with fixed price effects (Rotterdam and CBS) better explain consumers’ retail purchase allocation decisions for beef, lamb, pork, bacon and poultry compared with models containing variable price effects (NBR and differential AIDS). The real expenditures and the Hicksian demand elasticities are generally found to be quite different from earlier studies using AIDS models. A quality change index of meat consumption is constructed from the estimated CBS model estimation results and decomposed into real expenditure, substitution, trend, seasonal and residual effects.
Tipo: Journal Article Palavras-chave: Meat demand; Differential approach; Model selection; UK; Demand and Price Analysis.
Ano: 2000 URL: http://purl.umn.edu/15401
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Model Selection for Discrete Dependent Variables: Better Statistics for Better Steaks AgEcon
Norwood, F. Bailey; Lusk, Jayson L.; Brorsen, B. Wade.
Little research has been conducted on evaluating out-of sample forecasts of discrete dependent variables. This study describes the large and small sample properties of two forecast evaluation techniques for discrete dependent variables: receiver-operator curves and out-of-sample log-likelihood functions. The methods are shown to provide identical model rankings in large samples and similar rankings in small samples. The likelihood function method is better at detecting forecast accuracy in small samples. By improving forecasts of fed cattle quality grades, the forecast evaluation methods are shown to increase cattle marketing revenues by $2.59/head.
Tipo: Journal Article Palavras-chave: Discrete dependent variables; Forecasting; Likelihood functions; Model selection; Out-of-sample; Quality grades; Receiver-operator curves; Agribusiness.
Ano: 2004 URL: http://purl.umn.edu/30912
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Model selection for quantitative trait loci mapping in a full-sib family Genet. Mol. Biol.
Tong,Chunfa; Zhang,Bo; Li,Huogen; Shi,Jisen.
Statistical methods for mapping quantitative trait loci (QTLs) in full-sib forest trees, in which the number of alleles and linkage phase can vary from locus to locus, are still not well established. Previous studies assumed that the QTL segregation pattern was fixed throughout the genome in a full-sib family, despite the fact that this pattern can vary among regions of the genome. In this paper, we propose a method for selecting the appropriate model for QTL mapping based on the segregation of different types of markers and QTLs in a full-sib family. The QTL segregation patterns were classified into three types: test cross (1:1 segregation), F2 cross (1:2:1 segregation) and full cross (1:1:1:1 segregation). Akaike's information criterion (AIC), the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Full-sib family; Interval mapping; Model selection; Quantitative trait locus.
Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000400013
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On the Empirical Content of Demand Analysis AgEcon
Barten, Anton P..
Falsification of nontrivial empirical statements, of a statistical nature or not, is basically destructive. No wonder that it is rarely practiced. Rather than then abandoning a rejected null hypothesis, one tries to salvage it by looking for reasons why the rejection of an otherwise credible, plausible hypothesis occurs. One then attempts to modify the set-up in such a manner that formal rejection is avoided. Testing, in general, but specifically of nonnested hypotheses, can be seen as a kind of model selection. These issues are illustrated with examples from applied demand analysis: the testing of the homogeneity condition and of Slutsky symmetry and the choice of functional form for demand systems.
Tipo: Journal Article Palavras-chave: Demand analysis; Falsification; Homogeneity condition; Model selection; Symmetry condition.
Ano: 2003 URL: http://purl.umn.edu/43219
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Selection and validation of a complex fishery model using an uncertainty hierarchy ArchiMer
Lehuta, Sigrid; Petitgas, Pierre; Mahevas, Stephanie; Huret, Martin; Vermard, Youen; Uriarte, Andres; Record, Nicholas R..
Assessing the validity of a model is essential for its credibility especially when the model is used as decision making tool. Complex dynamic fishery models are recommended to investigate the functioning of fisheries and to assess the impact of management strategies, particularly spatial fishing regulations. However, their use is limited due to the difficulty and computational cost of parameterizing and gaining confidence, particularly for parameter rich models. These difficulties are compounded by uncertainty regarding parameter values, many of which are often taken from literature or estimated indirectly. Here we propose a methodology to improve confidence and understanding in the model, easily transferable to any complex model. The approach combines...
Tipo: Text Palavras-chave: Bay of Biscay anchovy; Dynamic fishery model; Model selection; Uncertainty; Validation.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00148/25965/24150.pdf
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The silence of the lambdas: a test of almost ideal and Rotterdam models: comment AgEcon
Brown, Mark G.; Lee, Jonq-Ying.
Tipo: Report Palavras-chave: Rotterdam model; AIDS; Model selection; Comment; Demand and Price Analysis.
Ano: 1993 URL: http://purl.umn.edu/52737
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Understanding what controls the spawning distribution of North Sea whiting (Merlangius merlangus) using a multi-model approach ArchiMer
Loots, Christophe; Vaz, Sandrine; Planque, Benjamin; Koubbi, Philippe.
The processes that control the spatial distribution of North Sea whiting (Merlangius merlangus) spawning adults are investigated using a statistical multi-model approach. Models of external and internal controls on the population, such as environmental conditions, spatial constraints, present or past spatial distribution, and demographic state of the population, are evaluated, compared and ranked to select those that are the best able to predict the observed distribution of spawning adults. Model selection is greatly influenced by the selection method, either based on data fitting or prediction, as well as by the threshold value used to stop the selection. Model selection based on prediction tends to select simpler models than selection based on data...
Tipo: Text Palavras-chave: Akaike information criterion; Hypotheses inference; Model selection; North Sea; Spawning distribution; Whiting.
Ano: 2011 URL: http://archimer.ifremer.fr/doc/00022/13313/11361.pdf
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