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Registros recuperados: 22
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A Comparison of Parametric Approximation Techniques to Continuous-Time Stochastic Dynamic Programming Problems AgEcon
Kompas, Tom; Chu, Long.
We compare three parametric techniques to approximate Hamilton-Jacobi-Bellman equations via unidimensional and multidimensional problems. The linear programming technique is very efficient for unidimensional problems and offers a balance of speed and accuracy for multidimensional problems. A comparable projection technique is shown to be slow, but has stable accuracy, whereas a perturbation technique has the least accuracy although its speed suffers least from the curse of dimensionality. The linear programming technique is also shown to be suitable for problems in resource management, including applications to biosecurity and marine reserve design.
Tipo: Journal Article Palavras-chave: Stochastic dynamic programming; Parametric approximation; Perturbation; Projection; Linear programming; Optimal fishing; Marine reserves; Research Methods/ Statistical Methods; Resource /Energy Economics and Policy; C61; C63; Q22.
Ano: 2010 URL: http://purl.umn.edu/95044
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A Flexible Parametric Family for the Modeling and Simulation of Yield Distributions AgEcon
Ramirez, Octavio A.; McDonald, Tanya U.; Carpio, Carlos E..
The distributions currently used to model and simulate crop yields are unable to accommodate a substantial subset of the theoretically feasible mean-variance-skewness-kurtosis (MVSK) hyperspace. Because these first four central moments are key determinants of shape, the available distributions might not be capable of adequately modeling all yield distributions that could be encountered in practice. This study introduces a system of distributions that can span the entire MVSK space and assesses its potential to serve as a more comprehensive parametric crop yield model, improving the breadth of distributional choices available to researchers and the likelihood of formulating proper parametric models.
Tipo: Journal Article Palavras-chave: Risk analysis; Parametric methods; Yield distributions; Yield modeling and simulation; Yield nonnormality; Agribusiness; Agricultural Finance; Crop Production/Industries; Land Economics/Use; Production Economics; Productivity Analysis; Research Methods/ Statistical Methods; C15; C16; C46; C63.
Ano: 2010 URL: http://purl.umn.edu/90675
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A Whole Farm Analysis of the Influence of Auto-Steer Navigation on Net Returns, Risk, and Production Practices AgEcon
Shockley, Jordan M.; Dillon, Carl R.; Stombaugh, Timothy S..
A whole farm economic analysis was conducted to provide a detailed assessment into the economic, risk, and production implications due to the adoption of auto-steer navigation. It was determined that auto-steer navigation was profitable for a grain farmer in Kentucky with net returns increasing up to 0.90% ($3.35/acre). Additionally, the technology could be used in reducing production risk. Adoption of the technology also alters production practices for optimal use.
Tipo: Journal Article Palavras-chave: Economics; Farm management; Mean-variance; Precision agriculture; Simulation; Farm Management; Risk and Uncertainty; C61; C63; D81; Q12; Q16.
Ano: 2011 URL: http://purl.umn.edu/100640
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An Evaluation of Overseas Oil Investment Projects under Uncertainty Using a Real Options Based Simulation Model AgEcon
Zhu, Lei; Zhang, ZhongXiang; Fan, Ying.
This paper applies real options theory to establish an overseas oil investment evaluation model that is based on Monte Carlo simulation and is solved by the Least Squares Monte-Carlo method. To better reflect the reality of overseas oil investment, our model has incorporated not only the uncertainties of oil price and investment cost but also the uncertainties of exchange rate and investment environment. These unique features have enabled our model to be best equipped to evaluate the value of oil overseas investment projects of three oil field sizes (large, medium, small) and under different resource tax systems (royalty tax and production sharing contracts). In our empirical setting, we have selected China as an investor country and Indonesia as an...
Tipo: Working Paper Palavras-chave: Overseas Oil Investment; Project Value; Real Options; Least Squares Monte-Carlo; Resource /Energy Economics and Policy; Q41; Q43; Q48; G31; O13; O22; C63.
Ano: 2011 URL: http://purl.umn.edu/119106
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Censored Probit Estimation with Correlation near the Boundary: A Useful Reparameteriztion AgEcon
Terza, Joseph V.; Tsai, Wei-Der.
The conventional computational algorithms for full information maximum likelihood (FIML) estimation of the censored probit model (see Farber, 1983), will sometimes fail to converge when the estimated value of the correlation coefficient (ñ) approaches ±1; even when the true value of ñ is not at a boundary. We show that a simple reparametrization of the censored probit model may afford straightforward Newton-Raphson convergence to the true FIML estimate for cases in which likelihood maximization under the conventional censored probit parameterization would have failed. Moreover, our method avoids the computational and inferential complications that arise in alternative methods that, based on a specified criterion, suggest fixing the estimated value of ñ at...
Tipo: Journal Article Palavras-chave: Sample selection; Endogenous treatment effects; Endogenous switching; Qualitative dependent variables; Informal elderly care; Research Methods/ Statistical Methods; I12; C24; C63.
Ano: 2006 URL: http://purl.umn.edu/50278
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Choice of Optimal Planting and Marketing Decisions for Fresh Vegetable Producers: A Mathematical Programming Approach AgEcon
Vassalos, Michael; Dillon, Carl R.; Coolong, Tim.
This study combines whole farm economic analysis with biophysical simulation techniques in order to achieve a twofold objective. First, the study seeks to develop a multiple enterprise vegetable farm model with a production and marketing decision interface and, second, to determine optimal production practices for Kentucky vegetable growers. Three vegetable crops are examined: tomatoes, bell peppers and sweet corn. The findings indicate that the risk associated with vegetable production can be significantly mitigated with diversification of production mix and with a greater number of transplanting dates. However, this reduction in risk comes at a high cost in terms of expected net returns.
Tipo: Presentation Palavras-chave: Vegetable production; Mean-variance; Biophysical simulation; Farm management; Farm Management; C61; C63; D81.
Ano: 2012 URL: http://purl.umn.edu/120016
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Combinatorial optimisation of a large, constrained simulation model: an application of compressed annealing AgEcon
Doole, Graeme J.; Pannell, David J..
Simulation models are valuable tools in the analysis of complex, highly constrained economic systems unsuitable for solution by mathematical programming. However, model size may hamper the efforts of practitioners to efficiently identify the most valuable configurations. This paper investigates the efficacy of a new metaheuristic procedure, compressed annealing, for the solution of large, constrained systems. This algorithm is used to investigate the value of incorporating a sown annual pasture, French serradella (Ornithopus sativa Brot. cv. Cadiz), between extended cropping sequences in the central wheat belt of Western Australia. Compressed annealing is shown to be a reliable means of considering constraints in complex optimisation problems in...
Tipo: Conference Paper or Presentation Palavras-chave: Combinatorial optimisation; Crop rotation; Simulated annealing; Research Methods/ Statistical Methods; C63; Q15.
Ano: 2007 URL: http://purl.umn.edu/10438
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Comparing numerical methods for solving the competitive storage model AgEcon
Gouel, Christophe.
This paper compares numerical methods for solving the competitive storage model. Since storage implies an inequality constraint, the solution methods must be considered carefully. The model is solved using value function iteration, and several projection approaches, including parameterised expectations and decision rules approximation. Using a penalty function approach to smooth the inequality constraint, perturbation methods are also applied. Parameterised expectations proves the most accurate method, while perturbation techniques are shown inadequate for solving this highly nonlinear model. The endogenous grid method allows rapid solution if supply is assumed to be inelastic.
Tipo: Working or Discussion Paper Palavras-chave: Binding constraint; Nonlinear rational expectations models; Numerical methods; Agricultural and Food Policy; C63; D84; E37.
Ano: 2010 URL: http://purl.umn.edu/115430
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Computational Complexity in Additive Hedonic Games AgEcon
Sung, Shao Chin; Dimitrov, Dinko.
We investigate the computational complexity of several decision problems in hedonic coalition formation games and demonstrate that attaining stability in such games remains NP-hard even when they are additive. Precisely, we prove that when either core stability or strict core stability is under consideration, the existence problem of a stable coalition structure is NP-hard in the strong sense. Furthermore, the corresponding decision problems with respect to the existence of a Nash stable coalition structure and of an individually stable coalition structure turn out to be NP-complete in the strong sense.
Tipo: Working or Discussion Paper Palavras-chave: Additive Preferences; Coalition Formation; Computational Complexity; Hedonic Games; NP-hard; NP-complete; Research Methods/ Statistical Methods; C63; C70; C71; D02; D70; D71.
Ano: 2008 URL: http://purl.umn.edu/46655
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Dynamic Optimization of Nitrogen Use in Agriculture AgEcon
Burnett, J. Wesley; Ferrer, Myra Clarisse R..
Agricultural production is highly dependent on inorganic substances including fertilizers. High-yielding crop varieties, such as corn, require large amounts of primary nutrients including nitrogen, phosphorus and potassium. Farmers often add a surplus of nutrients to crops to maximize yields. Utilization of primary nutrients has increased by more than 300% while that of nitrogen alone has increased by more than 600% between 1960 and 2007 (USDA, 2009). From 1964 to 2007, the use of nitrogen in the corn sector alone increased from 1,623,000 to 5,714,000 nutrient tons (USDA, 2009). While increasing production, increased fertilizer use can potentially create negative externalities in the form of nitrate-nitrogen contamination in groundwater....
Tipo: Working or Discussion Paper Palavras-chave: Environmental Economics; Nitrogen/Nitrate Contamination; Dynamic Optimization; Agriculture; Agricultural and Food Policy; Demand and Price Analysis; Environmental Economics and Policy; C61; C63; Q10; Q51; Q53.
Ano: 2010 URL: http://purl.umn.edu/96032
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Evaluation of Risk Management Methods for Satsuma Mandarin AgEcon
Lindsey, Jeanne K.; Duffy, Patricia A.; Nelson, Robert G.; Ebel, Robert C.; Dozier, William A..
Simulation of production budgets were used to compare net discounted returns and the distribution of returns under alternative risk-mitigation scenarios. Results indicate that the combination of freeze protection and crop insurance increases expected net discounted 20-year returns while decreasing the downside risk. Break-even prices ranged from $.257 to $.289 per pound. Crop insurance returns were constant across price.
Tipo: Conference Paper or Presentation Palavras-chave: Satsuma oranges; Freeze protection; Crop insurance; Production budget; Simulation; Crop Production/Industries; Farm Management; Risk and Uncertainty; C63; D81; Q12.
Ano: 2009 URL: http://purl.umn.edu/46754
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How appropriate are myopic optimization models to predict decision behaviour: A comparison between agent-based models and business management games AgEcon
Appel, Franziska; Musshoff, Oliver.
Agent-based models (ABM) are used in many cases of policy assessment in agriculture. But the behavioural assumptions of these models consider farmers as myopic optimizing profit maximizers. In this contribution we compare the behaviour of myopic computer agents with the behaviour of students playing a multi period business management game. We aim to answer the question, how far are agent-based models valid to map “real” human behaviour, so that ABM can be used well for policy impact assessment.
Tipo: Conference Paper or Presentation Palavras-chave: Agent-based models; Business management games; Policy impact analysis; Research Methods/ Statistical Methods; C63; C93; D22; Q18.
Ano: 2011 URL: http://purl.umn.edu/115994
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Location and Spatial Pricing in Agricultural Markets AgEcon
Graubner, Marten; Balmann, Alfons; Sexton, Richard J..
Agricultural markets often feature significant transport costs and spatially distributed production and processing which causes spatial imperfect competition. Spatial economics considers the firms’ decisions regarding location and spatial price strategy separately, usually on the demand side, and under restrictive assumptions. Therefore, alternative approaches are needed to explain, e.g., the location of new ethanol plants in the U.S. at peripheral as well as at central locations and the observation of different spatial price strategies in the market. We use an agent-based simulation model to analyze location and spatial pricing in a general model under multi-firm competition, two-dimensional space, and a continuum of potential price strategies. The...
Tipo: Conference Paper or Presentation Palavras-chave: Spatial competition; Location; Price discrimination; Oligopsony; Simulation; Industrial Organization; Research Methods/ Statistical Methods; C63; Q11; R32.
Ano: 2010 URL: http://purl.umn.edu/61225
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Numerical Analysis of Non-Constant Discounting with an Application to Renewable Resource Management AgEcon
Fujii, Tomoki; Karp, Larry S..
The possibility of non-constant discounting is important in environmental and resource management problems where current decisions affect welfare in the far-distant future, as with climate change. The difficulty of analyzing models with non-constant discounting limits their application. We describe and provide software to implement an algorithm to numerically obtain a Markov Perfect Equilibrium for an optimal control problem with non-constant discounting. The software is available online. We illustrate the approach by studying welfare and observational equivalence for a particular renewable resource management problem.
Tipo: Working or Discussion Paper Palavras-chave: Non-constant discounting; Numerical methods; Non-renewable resources; Observational equivalence; Research Methods/ Statistical Methods; Resource /Energy Economics and Policy; C63; Q20.
Ano: 2006 URL: http://purl.umn.edu/7199
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Optimal Equilibria of the Best Shot Game AgEcon
Dall'Asta, Luca; Pin, Paolo; Ramezanpour, Abolfazl.
We consider any network environment in which the “best shot game” is played. This is the case where the possible actions are only two for every node (0 and 1), and the best response for a node is 1 if and only if all her neighbors play 0. A natural application of the model is one in which the action 1 is the purchase of a good, which is locally a public good, in the sense that it will be available also to neighbors. This game will typically exhibit a great multiplicity of equilibria. Imagine a social planner whose scope is to find an optimal equilibrium, i.e. one in which the number of nodes playing 1 is minimal. To find such an equilibrium is a very hard task for any non-trivial network architecture. We propose an implementable mechanism that, in the...
Tipo: Working or Discussion Paper Palavras-chave: Networks; Best Shot Game; Simulated Annealing; Institutional and Behavioral Economics; C61; C63; D85; H41.
Ano: 2009 URL: http://purl.umn.edu/50684
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Optimal Management of a Potential Invader: The Case of Zebra Mussels in Florida AgEcon
Lee, Donna J.; Adams, Damian C.; Rossi, Frederick J..
Dominant users of Lake Okeechobee water resources are agricultural producers and recreational anglers. These uses will be directly affected, should the lake become infested with zebra mussels. We employ a probabilistic bioeconomic simulation model to estimate the potential impact of zebra mussels on consumptive water uses, recreational angling, and wetland ecosystem services under alternative public management scenarios. Without public management, the expected net economic impact from zebra mussels is - $244.1 million over 20 years. Public investment in prevention and eradication will yield a net expected gain of +$188.7 million, a superior strategy to either prevention or eradication alone.
Tipo: Journal Article Palavras-chave: Cost transfer; Fishing; Invasive species; Probability transition matrix; Surface water; Wetlands; C63; Q25; Q52; Q57; Q58.
Ano: 2007 URL: http://purl.umn.edu/37125
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Political Mergers as Coalition Formation AgEcon
Weese, Eric.
Political coalition formation games can describe the formation and dissolution of nations, as well as the creation of coalition governments, the establishment of political parties, and other similar phenomena. These games have been studied from a theoretical perspective, but the resulting models have not been used extensively in empirical work. This paper presents a method of estimating political coalition formation models with many-player coalitions, and then illustrates this method by estimating structural coefficients that describe the behaviour of municipalities during a recent set of municipal mergers in Japan. The method enables counterfactual analysis, which in the Japanese case shows that the national government could increase welfare via a...
Tipo: Working or Discussion Paper Palavras-chave: C63; D71; H77; Political Economy; Public Economics; Computational techniques; Coalitions; Municipalities.
Ano: 2011 URL: http://purl.umn.edu/107268
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Risk and Aversion in the Integrated Assessment of Climate Change AgEcon
Crost, Benjamin; Traeger, Christian P..
Tipo: Working or Discussion Paper Palavras-chave: Climate change; Uncertainty; Integrated assessment; Risk aversion; Intertemporal substitution; Recursive utility; Dynamic programming; Risk and Uncertainty; Q54; Q00; D90; C63.
Ano: 2010 URL: http://purl.umn.edu/90935
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Simulation in inventory management AgEcon
Marcikic, Aleksandra; Radovanov, Boris.
In this paper inventory management is analyzed as an organic part of the supply chain managing process. In today’s competitive economic environment traditional inventory policies should be improved. Simulation models enable a priori managing and analyzing variety of possible results and implication of selected inventory policies. The model presented in this paper uses the Monte Carlo simulation method and variables taken as random, in order to depict a harmonization and integration of dynamic quantitative analysis and theoretical, qualitative concepts of inventory management.
Tipo: Journal Article Palavras-chave: Monte Carlo simulation; Modeling; Inventory management; Supply chain management.; Research and Development/Tech Change/Emerging Technologies; C15; C63.
Ano: 2009 URL: http://purl.umn.edu/94592
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The Computational Difficulty of Bribery in Qualitative Coalitional Games AgEcon
Dowell, Andrew J.; Wooldridge, Michael; McBurney, Peter.
Qualitative coalitional games (QCG) are representations of coalitional games in which self interested agents, each with their own individual goals, group together in order to achieve a set of goals which satisfy all the agents within that group. In such a representation, it is the strategy of the agents to find the best coalition to join. Previous work into QCGs has investigated the computational complexity of determining which is the best coalition to join. We plan to expand on this work by investigating the computational complexity of computing agent power in QCGs as well as by showing that insincere strategies, particularly bribery, are possible when the envy-freeness assumption is removed but that it is computationally difficult to identify the best...
Tipo: Working or Discussion Paper Palavras-chave: Bribery; Coalition Formation; Computational Complexity; Marketing; C63; C78.
Ano: 2007 URL: http://purl.umn.edu/7444
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