Consulta: subjectFacets:"Markov chain"
Registros recuperados: 9
Data/hora: 05/06/2024 01:38:53

A probabilistic approach of flow-balanced network based on Markov chains
Provedor de dados: 5
Autores: Leguerrier, Delphine; Bacher, Cedric; Benoit, Eric; Niquil, Nathalie.
We used Markov chains to assess residence time, first passage time, rare of transfers between compartments, recycling index with a general mathematical formalism. Such a description applies to any flow-balanced system that can be modelled as a series of discrete stages or compartments through which matter flows. We derived a general set of equations from a probabilistic approach and applied them to a food web and a physical system derived from the literature. We therefore analysed preferential pathways of matter and behaviour of these systems and showed how it was possible to build up and exploit indices on the basis of a transition probability matrix describing the network, and to characterize with a generic algorithm: (1) the total indirect relationships...
Tipo: Text
Palavras-chave: First passage time; Box model; Food web model; Network; Transfer rate; Residence time; Markov chain.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2268.pdf

The Role of Small Farms in Structural Change
Provedor de dados: 31
Autores: Huettel,   Silke; Margarian,   Anne.
This paper explains regionally differentiated patterns of structural change based on a theoretical framework dealing with strategic interaction of farms on the land market. The main research question focuses on the causes of regionally persistent structures. An empirical Markov chain model is defined for the West German agricultural sector. Thereby it is possible to explain the probabilities of farm growth, decline or exit in terms of the current and former regional farm size structure. Further, the impact of variables describing the regional farm structure, thereby indicating market power of the large, the potential of high competition for land within a region and possibly high rents of the status quo in combination with sunk costs, is quantified. The...
Tipo: Working or Discussion Paper
Palavras-chave: Structural change; Strategic competition; Land market; Markov chain; Agribusiness; Agricultural and Food Policy; Community/Rural/Urban Development; Institutional and Behavioral Economics; Risk and Uncertainty.
Ano: 2009
URL: http://purl.umn.edu/59519

Modelling the Dairy Farm Size Distribution in Poland Using an Instrumental Variable Generalized Cross Entropy Markov Approach
Provedor de dados: 31
Autores: Tonini,   Axel; Jongeneel,   Roelof A.
The aim of this paper is to analyse the evolution of the dairy farm structure of Poland during the post-socialist period. First the paper focuses on how the farm structure has changed over time and what path it is likely to follow in the coming decade. Second, it is tested whether the evolution of farm size is explained by non-stationary effects. Finally, several statistical indicators are computed on farm mobility and on which farms are likely to survive. An instrumental variable generalised cross entropy Markov chain approach which incorporates prior information is applied for estimation. Prior information included general and plausible information on farm mobility and structural adjustments based on independent literature. The projections show that...
Tipo: Conference Paper or Presentation
Palavras-chave: Dairy; Farm size; Poland; Markov chain; Generalised cross entropy.; Livestock Production/Industries.
Ano: 2007
URL: http://purl.umn.edu/7784

Information Based Estimators for the Non-Stationary Transition Probability Matrix: An Application to the Danish Pork Industry
Provedor de dados: 31
Autores: Karantininis,   Kostas.
A generalised cross entropy instrumental variables estimator is used to recover the non-stationary transition probability matrix for the Danish pork industry. A technique is also developed to recover missing data points due to category re-specifications. The impact of a set of exogenous variables (prices of pork meat, inputs, and pork substitutes), are evaluated in the form of elasticities. An overall assessment of entry exit and growth of farms is performed.
Tipo: Working or Discussion Paper
Palavras-chave: Cross entropy estimator; Markov chain; Pork industry; Denmark; Livestock Production/Industries; C340; C130; Q120.
Ano: 2001
URL: http://purl.umn.edu/24198

The Role of Small Farms in Structural Change
Provedor de dados: 31
Autores: Huettel,   Silke; Margarian,   Anne.
This paper explains regionally differentiated patterns of structural change based on a theoretical framework dealing with strategic interaction of farms on the land market. The main research question focuses on the causes of regionally persistent structures. An empirical Markov chain model is defined for the West German agricultural sector. Thereby it is possible to explain the probabilities of farm growth, decline or exit in terms of the current and former regional farm size structure. Further, the impact of variables describing the regional farm structure, thereby indicating market power of the large, the potential of high competition for land within a region and possibly high rents of the status quo in combination with sunk costs, is quantified. The...
Tipo: Conference Paper or Presentation
Palavras-chave: Structural change; Strategic competition; Land market; Markov chain; Land Economics/Use.
Ano: 2009
URL: http://purl.umn.edu/52853

KRAM - A Sector Model of Danish Agriculture - Background and Framework Development
Provedor de dados: 31
Autores: Wiborg,   Torben.
A model of the Danish agricultural sector named KRAM (KVL's Regionalized Agricultural Model) is developed in this paper. KRAM can be described as a spatial, dynamic, nonlinear, programming sector model. KRAM's purpose is to make policy analysis in the complex market conditions Danish agriculture is working under today. In order to do this in the best possible way the model optimizes the production functions on a very disaggregated level. This allows for analysis of changes in physical constraints to production, as well as price changes. The model is capable of calculating some environmental effects of agricultural production, and provides detailed spatial description of the agricultural economy and production. The time horizon is 10 years, and the model...
Tipo: Working or Discussion Paper
Palavras-chave: Agricultural production; Positive mathematical programming; Dynamic agricultural sector model; Regions; Markov chain; Structural development; Crops; Pigs; Cows; GAMS; Production Economics.
Ano: 1998
URL: http://purl.umn.edu/18322

Structural Change of European Dairy Farms- A Cross-Regional Analysis
Provedor de dados: 31
Autores: Zimmermann,   Andrea; Heckelei,   Thomas.
Previous analyses of dairy farm structural change focused on the variation over time in one or a small number of regions. Here we present an EU15-wide analysis of the change of the number of farms in different size classes. The purpose is (1) to identify the differences in regional development patterns and (2) to measure the explanatory relevance and effect of key factors suggested in the literature. Apart from the unprecedented scope, the underlying Markov chain analysis also contributes by combining observed transitions in micro data with macro data on farm numbers. Results show widely significant impacts of most explanatory variables, but also reveal the complexity of the underlying processes.
Tipo: Conference Paper or Presentation
Palavras-chave: Structural change; Dairy farms; Markov chain; Cross-regional; EU; Agricultural and Food Policy.
Ano: 2010
URL: http://purl.umn.edu/61006

Dairy Quota and Farm Structural Change: A Case Study on the Netherlands
Provedor de dados: 31
Autores: Jongeneel,   Roelof A.; Tonini,   Axel.
This paper sets out to analyse the impact of milk quotas had on the dairy farm structure of the Netherlands. In addition projections on the likely farm structure under different milk quota scenarios are explored. Moreover mobility indicators characterizing structural change are developed and calculated. A Markov probability model is estimated relying on a generalized cross entropy approach. The introduction of milk quotas as of April 1, 1984 froze the dairy farm structural adjustment, at least initially. However, later on mobility started to increase, which is likely to reflect the quota tradability and lease possibilities. Moreover there is evidence that the milk quota regime has increased concentration of dairy production among farms with 50-69 cows. If...
Tipo: Conference Paper or Presentation
Palavras-chave: Dairy; Farm size; Netherlands; Markov chain; Generalized cross entropy; Agricultural and Food Policy; Farm Management; Livestock Production/Industries; Research Methods/ Statistical Methods.
Ano: 2008
URL: http://purl.umn.edu/6692

Entry, Exit, and Structural Change in Pennsylvania's Dairy Sector
Provedor de dados: 31
Autores: Stokes,   Jeffrey R.
Data on the number of Pennsylvania dairy farms by size category are analyzed in a Markov chain setting to determine factors affecting entry, exit, expansion, and contraction within the sector. Milk prices, milk price volatility, land prices, policy, and cow productivity all impact structural change in Pennsylvania's dairy sector. Stochastic simulation analysis suggests that the number of dairy farms in Pennsylvania will likely fall by only 2.0 percent to 2.5 percent annually over the next 20 years, indicating that dairy farming in Pennsylvania is likely to be a significant enterprise for the state in the foreseeable future.
Tipo: Journal Article
Palavras-chave: Dairy; Maximum entropy; Farm size; Markov chain; Simulation; Farm Management; Industrial Organization.
Ano: 2006
URL: http://purl.umn.edu/10218