SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Abbott, Brant; van Kooten, G. Cornelis.

Tigers are a threatened species that might soon disappear in the wild. Not only are tigers threatened by deteriorating and declining habitat, but poachers continue to kill tigers for traditional medicine, decoration pieces and so on. Although international trade in tiger products has been banned since 1987 and domestic trade within China since 1993, tigers continue to be poached and Chinese entrepreneurs have established tiger farms in anticipation of their demise. While China desires to permit sale of tiger products from captive-bred tigers, this is opposed on the grounds that it likely encourages illegal killing. Instead, wildlife conservationists lobby for more spending on anti-poaching and trade-ban enforcement. In this study, a mathematical...

The Effect of Climate Change on Wetlands and Waterfowl in Western Canada: Incorporating Cropping Decisions into a Bioeconomic Model

Palavras-chave: Endangered species; Extinction; Wildlife farming and bioeconomics; Environmental Economics and Policy; Q57; Q27; C61; F13.

Ano: 2009

URL: http://purl.umn.edu/46994

Withey, Patrick; van Kooten, G. Cornelis.

We extend an earlier bioeconomic model of optimal duck harvest and wetland retention in the Prairie Pothole Region of Western Canada to include cropping decisions. Instead of a single state equation, the model has two state equations representing the population dynamics of ducks and the amount of wetlands. We use the model to estimate the impact of climate change on wetlands and waterfowl, including direct climate effects as well as land use change due to biofuel policies aimed at mitigating climate change. The model predicts that climate change will reduce wetlands by 47-56 percent from historic levels. Land use change is expected to reduce wetlands by 45 percent from historic levels, whereas direct climate effects will range from a reduction of 2-11...

Implications of Expanding Bioenergy Production from Wood in British Columbia: An Application of a Regional Wood Fibre Allocation Model

Palavras-chave: Bioeconomic modeling; Wetland protection; Wildlife management; Climate change; Biofuels; Environmental Economics and Policy; Q57; C61; Q25; Q54; C13; Q10; Q16.

Ano: 2011

URL: http://purl.umn.edu/117437

Stennes, Brad; Niquidet, Kurt; van Kooten, G. Cornelis.

Energy has been produced from woody biomass in British Columbia for many decades, but it was used primarily within the pulp and paper sector, using residual streams from timber processing, to create heat and electricity for on-site use. More recently, there has been limited stand-alone electricity production and increasing capacity to produce wood pellets, with both using ‘waste’ from the sawmill sector. Hence, most of the low-cost feedstock sources associated with traditional timber processing is now fully employed. While previous studies model bioenergy production in isolation, we employ a transportation model of the BC forest sector with 24 regions to demonstrate that it is necessary to consider the interaction between utilization of woody feedstock for...

Optimal Equilibria of the Best Shot Game

Palavras-chave: Bioenergy production from wood fibre; Mountain pine beetle; Competition for fibre; Environmental Economics and Policy; Resource /Energy Economics and Policy; Q23; Q42; C61; Q54.

Ano: 2009

URL: http://purl.umn.edu/50782

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...

Modelos de valoracion en ambiente de incertidumbre

Palavras-chave: Networks; Best Shot Game; Simulated Annealing; Institutional and Behavioral Economics; C61; C63; D85; H41.

Ano: 2009

URL: http://purl.umn.edu/50684

Bellver, Jeronimo Aznar; Martinez, Francisco Guijarro.

Resumen En este trabajo se presentan diversos modelos de valoración en ambiente de incertidumbre que combinan información precisa e imprecisa. En el desarrollo de los mismos se ha extendido la técnica de programación por metas básica a modelos que permiten considerar intervalos en la expresión del precio o las variables explicativas del mismo, enunciando una serie de proposiciones con las que se obtiene un completo conocimiento sobre el grado de adecuación entre los valores observados en el precio y los valores estimados por la función de valoración. Así mismo, se ha formulado un índice de adecuación que permite comparar diferentes modelos obtenidos mediante la metodología propuesta. Palabras clave: Valoración, Incertidumbre, Programación por metas con...

Tipo: Journal Article

Palavras-chave: Valuation; Uncertainty; Interval goal programming; Research Methods/ Statistical Methods; C61; G12; Q14.

Ano: 2004

URL: http://purl.umn.edu/28731

Evading Farm Support Reduction via Efficient Input Use: The Case of Greek Cotton Growers

Pantzios, Christos J.; Rozakis, Stelios; Tzouvelekas, Vangelis.

The present paper examines the importance that efficient resource use may have for cotton growers under the current EU policy regime. To that end, input-oriented technical and scale efficiency score for a sample of 172 cotton-growing farms are empirically quantified. The results suggest that cotton farms in the sample are not efficient mainly due to the nature of the policy regime governing the sector throughout EU. By becoming efficient, the co-responsibility levy will be reduced by 18.3% and farms may increase their profits by 50.1% on the average.

Tipo: Journal Article

Palavras-chave: Co-responsibility levy; Cotton farms; Goal programming; Greece; Scale and technical efficiency; Stochastic frontier model; Production Economics; D24; Q12; Q16; C61.

Ano: 2006

URL: http://purl.umn.edu/43787

ENDOGENOUS RECOMBINANT GROWTH

Tsur, Yacov; Zemel, Amos.

We extend Weitzman's (1998) recombinant growth framework to include endogenous R&D decisions. The analysis is carried out in the (knowledge-capital) state space by means of two characteristic curves: one is identified as a turnpike along which growing economies evolve; the other attracts stagnating economies. Sustained growth depends on a condition relating the slopes of the characteristic curves as well as on a minimal endowment requirement. A growing economy reaches the turnpike at a most rapid R&D rate and evolves along it thereafter. In the long run, the rate of growth and the income shares devoted to R&D, saving and consumption approach constant values that depend on the asymptotic characteristic slopes.

DYNAMIC-SPATIAL MANAGEMENT OF COASTAL AQUIFERS

Palavras-chave: Knowledge generation; Combined ideas; Endogenous R&D; Balanced growth; Research Methods/ Statistical Methods; C61; O31; O41.

Ano: 2006

URL: http://purl.umn.edu/7135

Kan, Iddo; Leizarowitz, Arie; Tsur, Yacov.

We analyze the management of a coastal aquifer under seawater intrusion using distributed control methods. The aquifer's state is taken as the water head elevation, which varies with time and in space since extraction, natural recharge and lateral water flows vary with time and in space. The water head, in turn, induces a temporal-spatial seawater intrusion process, which changes the volume of fresh water in the aquifer. Under reasonable conditions we show that the optimal state converges to a steady state process that is constant in time. We characterize the optimal steady state process in terms of a standard control problem (in space) and offer a tractable algorithm to solve for it.

Determination of Optimal Environmental Flow Acquisition in Kor Basin, Doroudzan Dam

Palavras-chave: Distributed control; Groundwater; Optimal exploitation; Seawater intrusion; Resource /Energy Economics and Policy; C61; C62; Q25.

Ano: 2007

URL: http://purl.umn.edu/7131

Asad Falsafi Zadeh, Neda; Sabouhi Sabouni, Mahmood.

In current study, an irrigation examination and acquisition of environmental water in Kor River fields, that is dominated from Doroudzan dam to Bakhtegan Lake, was done by an integrated economy-environmental model. The model was considered by economic, hydrologic and agronomic components. In the economic component, an optimal harvesting of water was done using non-linear programming in two scenarios; with and without environmental water constraint. Solutions from simulation of environmental data in the hydrologic component, was used as initial data in the economic component. In the agronomic component, actual crop yield in wet, normal and dry years was determined using the relationship between crop yield and irrigation water amount. Results showed that,...

2011 Updated Arkansas Global Rice Model

Palavras-chave: Expected Net Income; Hydrology; Non-Linear Programming Model; Deficit Irrigation; Consumer/Household Economics; Environmental Economics and Policy; Farm Management; Food Consumption/Nutrition/Food Safety; Production Economics; Risk and Uncertainty; C32; C61; D42; D61.

Ano: 2009

URL: http://purl.umn.edu/50258

Wailes, Eric J.; Chavez, Eddie C..

The Arkansas Global Rice Model is based on a multi-country statistical simulation and econometric framework. The model is disaggregated by five world regions: Africa, the Americas, Asia, Europe, and Oceania. Each region includes country models which have a supply sector, a demand sector, a trade, stocks and price linkage equations. All equations used in this model are estimated using econometric procedures or identities. Estimates are based upon a set of explanatory variables including exogenous macroeconomic factors such as income, population, inflation rate, technology development, and especially, government determined policy variables which reflect the various mechanisms by which countries intervene in their rice sector economy. Individual country...

Tipo: Report

Palavras-chave: Rice; Trade model; Policy; Agricultural and Food Policy; Research and Development/Tech Change/Emerging Technologies; CO2; C61; F11; F14; Q17; Q18.

Ano: 2011

URL: http://purl.umn.edu/102650

MUNICIPALITY DISAGGREGATION OF GERMAN'S AGRICULTURAL SECTOR MODEL RAUMIS

Roeder, Norbert; Gocht, Alexander.

Since several decades the RAUMIS modelling system is applied for policy impact assessments to measure the impact of agriculture on the environment. A disaggregation at the municipality level with more than 9.000 administrative units, instead of currently used 316 counties, would tremendously improve the environmental impact analysis. Two sets of data are used for this purpose. The first are geo-referenced data, that are, however, incomplete with respect its coverage of production activities in agriculture. The second set is the micro census statistic itself, that has a full coverage, but data protection rules (DPR) prohibit its straightforward use. The paper show how this bottleneck can be passed to obtain a reliable modelling data set at municipality...

“Waiting for Godot”- Restructuring on Small Family Farms

Palavras-chave: Highest Posterior Density estimator (HPD); RAUMIS; Down scaling; Agricultural and Food Policy; C11; C61; C81; Q15.

Ano: 2011

URL: http://purl.umn.edu/99248

Jack, Claire G.; Moss, Joan E.; Wallace, Michael T..

This paper examines the extent to which favourable off-farm labour market conditions coupled with growth in land values have contributed to the observed resilience of small scale family farms. We use data from Northern Ireland and employ farm household optimisation models to analyse household decision making processes that contribute to the observed inertia in farm structure. The analysis indicates that farm household behaviour is influenced not just by current farm income, but also expected capital asset returns. Increased wealth, associated with continuing land ownership, gives rise to the proposition that the link between off-farm incomes, increased land values and remaining in farming may be associated with farmers pursuing wealth maximizing...

Stochastic Utility-Efficient Programming of Organic Dairy Farms

Palavras-chave: Farm households; Resilience; Wealth accumulation; Off-farm income; Consumer/Household Economics; Productivity Analysis; C61; Q12.

Ano: 2009

URL: http://purl.umn.edu/52835

Flaten, Ola; Lien, Gudbrand D..

Opportunities to make sequential decisions and adjust activities as a season progresses and more information becomes available characterize the farm management process. In this paper, we present a discrete stochastic two-stage utility efficient programming model of organic dairy farms, which includes risk aversion in the decision maker's objective function as well as both embedded risk (stochastic programming with resource) and non-embedded risk (stochastic programming without recourse). Historical farm accountancy data and subjective judgments were combined to assess the nature of the uncertainty that affects the possible consequences of the decisions. The programming model was used within a stochastic dominance framework to examine optimal strategies...

Mixed Crop Livestock Farming Incorporating Agroforestry Orchards Facing the New Cap

Palavras-chave: Agriculture; Risk analysis; Stochastic programming; Stochastic dominance; Organic farming; Livestock Production/Industries; Q12; C61.

Ano: 2005

URL: http://purl.umn.edu/24743

Ducros, Denis; Kephaliacos, Charilaos; Ridier, Aude.

In the context of the new CAP, decoupling subsidies from production should incite farmers to reorganize their production systems, particularly through diversification opportunities. In this paper we focus our analysis on the conditions that could permit the development of extensive orchards by modelling mixed crop livestock farms, which incorporate orchards. A mathematical programming model is built to simulate various intensification levels characterizing different technical pathways within the different farm activities (cattle breeding, forage fields, arboriculture). This model also enables us to take into account some environmental indicators related to these pathways. Moreover, the method illustrates technical complementarities existing within the...

Análisis de alternativas para la eliminación de la sobreexplotación de acuíferos en el Valle de Guadalentín

Palavras-chave: Decoupling; Diversification; Agroforestry orchards; Joint production; Mathematical programming; Agribusiness; C61; D24; Q12; Q21.

Ano: 2005

URL: http://purl.umn.edu/24532

Calatrava-Leyva, Javier; Guillem, Amanda; Martinez-Granados, David.

In this paper we analyse the economic impact of alternative water management instruments that allow addressing the problem of non-renewable groundwater pumping in the aquifers of the Guadalentín Valley (southeast Spain). Their impact is assessed using a partial equilibrium mathematical programming model that maximises the farm net margin resulting from the use of the available water resources for irrigation in the area. Our results show that the buyback of groundwater pumping rights is the option with the greatest public budgetary cost and economic impact. On the contrary, the combination of an environmental tax on groundwater pumping and the substitution of groundwater by subsidised desalinised water allow eliminating aquifer overdraft in the area while...

Tipo: Article

Palavras-chave: Groundwater; Water economics; Water demand; Mathematical programming; Irrigation; Agricultural and Food Policy; Environmental Economics and Policy; Land Economics/Use; Resource /Energy Economics and Policy; Q25; C61.

Ano: 2011

URL: http://purl.umn.edu/120197

Optimal Structure of Farms in a Region - A Modeling Approach

Majewski, Edward; Was, Adam.

In the paper the regional, optimization model of agriculture and its use for predicting probable reactions of farmers and assessing the impact of the adaptation processes in the farming sector to agricultural policy changes and macroeconomic developments are presented. Two-phases modeling approach has been applied, with the use of linear programming, static optimization models a farm model, used to optimize the production structure of the farms typical for the region, and an agricultural sector model, used to determine the optimal farm and production structures within a region. An attempt have been made to incorporate in the model both micro and macroeconomic parameters. The result show, that different scenarios adjustments in farming sector in the...

Tradable Substitution Rights: Simulation of the Cost-Efficiency of a Nitrogen Reduction in the Pig Finishing Sector

Palavras-chave: Regional model of agriculture; Optimization; Farm strucure; Agribusiness; C61.

Ano: 2005

URL: http://purl.umn.edu/24571

Carlier, Peter Jan; Lauwers, Ludwig H.; Mathijs, Erik.

To comply with the European Nitrate Directive, the Flemish manure policy has been elaborated mainly on the base of command and control measures (maximum fertilisation limits etc.). In literature, however, tradable permits are described as a cost efficient and effective instrument. Applied to nutrient emission they might offer an alternative for the current, expensive manure policy. In this publication both policy instruments are compared by means of simulation models. Based on accountacy data from 190 pig finishing farms, it is shown that tradable rights may result in cost savings of over 88%, compared to the most cost efficient command and control model. This result indicates that tradable permits at least need to be considered as a plausible policy...

An Agro-Economic Production Model for a Middle European River Basin - First Results of CAP Reform Scenario Calculations

Palavras-chave: Tradable permits; Agriculture; Command and control; Nitrogen; Linear programming; Livestock Production/Industries; C61; D23; H23; Q58; Q52.

Ano: 2005

URL: http://purl.umn.edu/24746

Henseler, Martin; Krimly, Tatjana; Wirsig, Alexander.

ACRE is an Agro-eConomic model for agricultural pRoduction on rEgional level. Based on an extension of Positive Mathematical Programming (PMP) this model was developed as a decision tool for politics with respect to questions of global change- and political scenarios. Currently, ACRE is applied in the RIVERTWIN-Neckar project and politic scenarios of the CAP reform 2003 were calculated. This paper introduces ACRE, its theoretical framework, and the first results of political scenario calculations, which where done for the Neckar river basin.

Choice of Optimal Planting and Marketing Decisions for Fresh Vegetable Producers: A Mathematical Programming Approach

Palavras-chave: Agricultural production model; Regional model; Interdisciplinary projects; CAP reform 2003; Positive Mathematical Programming; Agricultural and Food Policy; E23; Q15; Q21; Q18; C61.

Ano: 2006

URL: http://purl.umn.edu/25612

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

A Microeconomic Model for Subsidies Allocation: the Case of Belarus

Svetlov, Nikolai M.; Kazakevich, Iryna A..

The paper develops a microeconomic methodological framework that allows approaching subsidy allocation across the types of assets and impact of subsidies on agricultural outputs and profits. The methodology is based on a non-parametric production frontier estimation. The empirical application is made to 1084 Belarusian corporate farms. The results suggest targeting governmental support at grain and milk production. In this case, 4.14 trillion Belarusian roubles of subsidies increase the overall profit of the sample farms by 1.46 trillion. In the case of targeting, the farms with higher overall efficiency are more sensitive to the support and are able to absorb larger amount of subsidies. The opposite is true in the absence of targeting.