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

Hennessy, David A.; Roosen, Jutta.

The decision to replant a fire blight-susceptible apple orchard is analyzed. Embedding the problem into an equilibrium framework facilitates the welfare analysis of changes in orchard survival probabilities arising from a ban on antibiotics use. We estimate the structural impacts and welfare changes of the ban.

Dynamics, Stability, and Foresight in the Shapley-Scarf Housing Market

Palavras-chave: Antibiotics; Apple orchard; Dynamics; Equilibrium; Replanting; Resistance; Truncated Poisson process; Environmental Economics and Policy; Research and Development/Tech Change/Emerging Technologies.

Ano: 1999

URL: http://purl.umn.edu/21698

Kamijo, Yoshio; Kawasaki, Ryo.

While most of the literature starting with Shapley and Scarf (1974) have considered a static exchange economy with indivisibilities, this paper studies the dynamics of such an economy. We find that both the dynamics generated by competitive equilibrium and the one generated by weakly dominance relation, converge to a set of allocations we define as strictly stable, which we can show to exist. Moreover, we show that even when only pairwise exchanges between two traders are allowed, the strictly stable allocations are attained eventually if traders are sufficiently farsighted.

Managing a Common Renewable Resource in Asymmetric Information

Palavras-chave: Indivisible Goods Market; Dynamics; Competitive Allocation; Strict Core; Foresight; Stable Set; Productivity Analysis; D78; C71.

Ano: 2009

URL: http://purl.umn.edu/52526

Catro, D. Fuentes; Jayet, Pierre-Alain; Rotillon, Gilles.

The clear definition of property rights is not a sufficient condition to prevent congestion effects in commons. In this paper we present how interesting can be the coordination among owners in the preservation of the common good. Our approach takes into account economic dynamics and incentive mechanisms in a hidden information context. We consider a natural resource which is being used up for a continuum of producers on a common property regime. We also consider that each producer has an individual performance index which is a hidden information of the rest of players. We introduce coordination in the sense of a global maximization of the joint profit. If there is no coordination among the producers, their behavior leads to complete rent dissipation....

Competition and Dynamics in Trade Patterns: Hungarian and Slovenian Agri-Food Trade with the European Unions' Trading Partners

Palavras-chave: Commons; Natural Resources; Dynamics; Asymmetric Information; Contracts; Environmental Economics and Policy.

Ano: 2000

URL: http://purl.umn.edu/24893

Bojnec, Stefan; Ferto, Imre.

Trade balances and unit values in Hungarian and Slovenian bilateral agri-food trade with Austria, Germany and Italy, respectively, to distinguish types of the one-way and the two-way trade flows, categories of price competition and categories of quality competition in the twoway trade flows, their dynamics and stability over time are analyzed. The two-way matched trade flows prevail among trade types. In the matched two-way bilateral agri-food trade there is prevalence of categories of price competition over categories of non-price competition, but varies across trading partners. In Hungarian agri-food trade the first category of successful price competition and the third category of successful non-price or quality competition prevail, suggesting...

Sales Promotion and Cooperative Retail Pricing Strategies

Palavras-chave: Competition; Trade types; Dynamics; Mobility index; F12; Q17; Q18; International Relations/Trade.

Ano: 2006

URL: http://purl.umn.edu/25760

Richards, Timothy J.; Patterson, Paul M..

Supermarket retailers make strategic pricing decisions in a high-frequency, repeated game environment both in buying and selling fresh produce. In this context, there is some question as to whether a non-cooperative equilibrium can emerge that produces margins above the competitive level. Supermarket pricing results from tacitly collusive equilibria supported by trigger price strategies played in upstream markets. Upstream activities are, in turn, driven by periodic retail price promotions. We test this hypothesis using a sample of fresh produce pricing data from 20 supermarket chains in markets distributed throughout the U.S. Our results support the existence of tacitly collusive non-cooperative equilibria in upstream and downstream markets.

An Assessment of Dynamic Behavior in the U.S. Catfish Market: An Application of the Generalized Dynamic Rotterdam Model

Palavras-chave: Dynamics; Game theory; Nash equilibrium; Perishables; Supermarkets; Tacit collusion; Trigger prices.; Demand and Price Analysis.

Ano: 2004

URL: http://purl.umn.edu/28542

Muhammad, Andrew; Jones, Keithly G..

The generalized dynamic Rotterdam model was used in estimating U.S. demand for disaggregated catfish. The overall goal was to examine habit persistence in consumption and to determine the adjustment process in demand. Results indicated that it took up to 1 month for catfish-product demand to fully adjust to changes in expenditures and prices. Additionally, habit persistence played a role in demand where present consumption of a given product was positively affected by past consumption of that product. Consequently, U.S. catfish demand was significantly more elastic in the long-run.

Tipo: Journal Article

Palavras-chave: Catfish; Demand; Dynamics; Partial adjustment; Rotterdam model; Agribusiness; Consumer/Household Economics; Demand and Price Analysis; Food Consumption/Nutrition/Food Safety; Institutional and Behavioral Economics; C51; Q11; Q13; Q17.

Ano: 2009

URL: http://purl.umn.edu/56660

Dynamic general equilibrium analysis of improved weed management in Australia's winter cropping systems

Wittwer, Glyn; Vere, David T.; Jones, Randall E.; Griffith, Garry R..

A recent analysis indicated that the direct financial cost of weeds to Australia’s winter grain sectorwas approximately $A1.2bn in 1998–1999. Costs of thismagnitude represent a large recurring productivity loss in an agricultural sector that is sufficient to impact significantly on regional economies.Using amulti-regional dynamic computable general equilibrium model, we simulate the general equilibrium effects of a hypothetical successful campaign to reduce the economic costs of weeds. We assume that an additional $50m of R&D spread over five years is targeted at reducing the additional costs and reduced yields arising from weeds in various broadacre crops. Following this R&D effort, one-tenth of the losses arising from weeds is temporarily...

Tipo: Article

Palavras-chave: CGE modelling; Dynamics; Weed management; Crop Production/Industries.

Ano: 2005

URL: http://purl.umn.edu/118584

Dynamics and Limited Cooperation In International Environmental Agreements

Karp, Larry S.; Sacheti, Sandeep.

The amount of cooperation needed to improve the welfare of signatories of International Environmental Agreements (IEAs), in the presence of market imperfections, depends on the characteristics of pollution. In a dynamic model, the conventional wisdom on the effect of free-riding needs to be modified for certain types of pollution problems. For local pollution problems, a sufficient level of free-riding actually promotes signatories' welfare. For global pollution problems, the conventional wisdom is correct insofar as free-riding makes it more difficult to form a successful IEA. However, for some global pollution problems, free-riding may disappear. A static model may overstate or understate the difficulty of forming a successful IEA. The effect of an IEA...

Dynamic Field Experiments in Development Economics: Risk Valuation in Morocco, Kenya, and Peru

Palavras-chave: International Environmental Agreements; Environmental stocks; Dynamics; Free-riding; Environmental Economics and Policy; International Relations/Trade; F12; F42; Q28.

Ano: 1997

URL: http://purl.umn.edu/6212

Lybbert, Travis J.; Galarza, Francisco B.; McPeak, John G.; Barrett, Christopher B.; Boucher, Stephen R.; Carter, Michael R.; Chantarat, Sommarat; Fadlaoui, Aziz; Mude, Andrew G..

The effective design and implementation of interventions that reduce vulnerability and poverty require a solid understanding of underlying poverty dynamics and associated behavioral responses. Stochastic and dynamic benefit streams can make it difficult for the poor to learn the value of such interventions to them. We explore how dynamic field experiments can help (i) intended beneficiaries to learn and understand these complicated benefit streams, and (ii) researchers to better understand how the poor respond to risk when faced with nonlinear welfare dynamics. We discuss and analyze dynamic risk valuation experiments in Morocco, Peru, and Kenya.

Tipo: Journal Article

Palavras-chave: Poverty; Risk and uncertainty; Dynamics; Experiments; Kenya; Morocco; Peru; International Development; Research Methods/ Statistical Methods; Risk and Uncertainty.

Ano: 2010

URL: http://purl.umn.edu/90791

The Dynamics of Food Stamp Program Participation: A Lagged Dependent Variable Approach

Atasoy, Sibel; Mills, Bradford F.; Parmeter, Christopher F..

This paper investigates the existence of Food Stamp Program (FSP) participation state dependence and its sources in by analyzing the dynamics of participation in the FSP using a lagged dependent variable approach. Results show that FSP receipt in the previous year is an important determinant of current FSP receipt. However, estimated persistence rates declined significantly after 1996, suggesting that long-term FSP dependency was reduced following broader welfare reform measures. The source of FSP state dependence among low-income households is mostly structural implying that a welfare trap does exist.

The persistence of drought impacts across growing seasons: a dynamic stochastic analysis

Palavras-chave: Food Stamp Program; State Dependence; Dynamics; Welfare Trap; Food Security and Poverty; Health Economics and Policy; I38; C23; C25.

Ano: 2010

URL: http://purl.umn.edu/60963

Peck, Dannele E.; Adams, Richard M..

Agricultural producers throughout much of the United States experienced one of the most severe droughts in the last 100 years during the years 1999-2006. The prolonged nature of this drought highlights a need to better understand the impacts and management of drought across growing seasons, rather than just within a growing season. Producers express specific concern about the tendency of drought impacts to persist even after drought itself has subsided. The persistence of drought impacts has received limited attention in the economics literature. The objectives of this study are two-fold: 1) to determine whether inter-year dynamics, in the form of agronomic constraints and financial flows, can cause persistence of a drought's impact in years subsequent...

Uma análise das capacidades tecnológicas da agroindústria canavieira em Minas Gerais

Palavras-chave: Drought; Preparedness; Response; Uncertainty; Dynamics; Discrete stochastic programming; Agriculture; Irrigation; Eastern Oregon; Row crops; Crop rotation; Crop Production/Industries; Risk and Uncertainty.

Ano: 2007

URL: http://purl.umn.edu/9253

Shikida, Pery Francisco Assis; Azevedo, Paulo Furquim de; Vian, Carlos Eduardo de Freitas.

This paper aims to appraise the technological capabilities of sugarcane agro-industry in Minas Gerais State, that has the second largest area planted with sugarcane in Brazil, that is 679.000 ha. A field research survey with sugar and ethanol mills provides the primary data for assessing technological capabilities. The theoretical approach used was the technological capabilities matrix, which is based in Lall (1992), being this matrix divided into three specifications: basic (simple routine), intermediate (adaptive duplicative) and advanced (innovative risky). As a main finding, this sugarcane agro-industry, technically qualified and with low cost, presents a reasonable domain of basic and intermediate technological capabilities. However, the advanced...

Tipo: Journal Article

Palavras-chave: Dynamics; Technology; Sugar; Ethanol; Research and Development/Tech Change/Emerging Technologies.

Ano: 2010

URL: http://purl.umn.edu/95074

DYNAMIC MICROECONOMETRIC APPROACHES TO ANALYSING AGRICULTURAL POLICY

Gardebroek, Cornelis; Oude Lansink, Alfons G.J.M..

Micro-econometric models have become a standard and powerful tool in analysing agricultural policies. In this paper we assess the contributions that have been made in the agricultural economics literature to dynamic microeconometric models of firms and households that are estimated using microdata. After discussing developments in dynamic investment models, dynamic household models, dynamic discrete choice models and dynamic efficiency models we give promising directions for future research and discuss implications for future data collection.

Information, Stability and Dynamics in Networks under Institutional Constraints

Palavras-chave: Dynamics; Microeconometric models; Agricultural policy analysis; Agricultural and Food Policy; Research Methods/ Statistical Methods.

Ano: 2008

URL: http://purl.umn.edu/6592

Olaizola, Norma; Valenciano, Federico.

In this paper we study the effects of institutional constraints on stability, efficiency and network formation. More precisely, an exogenous "societal cover" consisting of a collection of possibly overlapping subsets that covers the whole set of players and such that no set in this collection is contained in another specifies the social organization in different groups or "societies". It is assumed that a player may initiate links only with players that belong to at least one society that s/he also belongs to, thus restricting the feasible strategies and networks. In this way only the players in the possibly empty "societal core", i.e., those that belong to all societies, may initiate links with all individuals. In this setting the part of the current...

ON THE OPTIMAL IMPLEMENTATION OF AGRICULTURAL POLICY REFORMS

Palavras-chave: Network; Non-cooperative Game; Dynamics; Environmental Economics and Policy; C72.

Ano: 2010

URL: http://purl.umn.edu/96844

Femenia, Fabienne; Gohin, Alexandre.

Economic analyses of farm policies generally focus on the long run, steady state impacts while the transition dynamics are often overlooked. In this paper we develop a determinist dynamic computable general equilibrium analysis allowing agents to form imperfect versus pefect expectations. Using an illustrative CAP reform scenario, we simulate an abrupt versus a gradual implementation of this reform. Our results show that if economic agents are able to perfectly anticipate the impacts of the reform, then delaying its implementation is never optimal. On the other hand, if agents gradually learn from market developments, then we find some cases where a gradual implementation of this reform is welfare improving. Such gradual implementation allows minimizing...

Análise temporal da heterogeneidade florística e estrutural em uma floresta ribeirinha

Palavras-chave: Dynamics; Transition; Farm Policies; Welfare; Agricultural and Food Policy; Political Economy.

Ano: 2010

URL: http://purl.umn.edu/91285

Rev. Bras. Bot.

BERTANI,DANIELA FESSEL; RODRIGUES,RICARDO RIBEIRO; BATISTA,JOÃO LUIZ FERREIRA; SHEPHERD,GEORGE JOHN.

Neste trabalho, foram estudadas a composição florística e a estrutura fitossociológica da vegetação em um fragmento de floresta ribeirinha, ao longo do rio Passa Cinco, Ipeúna, SP. Foram amostradas 157 parcelas contínuas de 5 x 10 m, em uma área de 0,785 ha. Foram feitas medidas de diâmetro e mapeados todos os indivíduos com DAP maior ou igual a 5 cm, em 1989 e 1998. Constatou-se a presença de um mosaico vegetacional e discutiram-se os possíveis fatores definidores deste mosaico. Foram, também, verificadas as alterações florísticas e fitossociológicas na área após nove anos. As análises multivariadas da vegetação mostraram a presença de três grupos vegetacionais com grande sobreposição aos três tipos de solo identificados na área. As análises quantitativas...

Dinâmica da reprodução do cascudo, Rineloricaria latirostris Boulenger (Siluriformes, Loricariidae) do rio Passa Cinco, Ipeúna, São Paulo

Palavras-chave: Tropical riverine forest; Tree communities; Dynamics; Soil; Topography.

Ano: 2001

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042001000100002

Zoologia

Barbieri,Geraldo.

Aspects of reproduction of Rineloricaria latirostris Boulenger, 1899 of Passa Cinco river (Ipeúna, São Paulo) were investigated during 18 months. The spawing period was determined by the analysis of the maturation curve, based of the monthly variation of the gonadosomatic index and condition factor. The size and age on the maturation and fecundity were also determined. The fecundity was realted to some parameters such as total length and total weight.

Contributions of the complexity paradigm to the understanding of Cerrado's organization and dynamics

Palavras-chave: Reproduction; Dynamics; Maturation; Fecundity.

Ano: 1994

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751994000400003

Anais da ABC (AABC)

MATTOS,SÉRGIO H.V.L. DE; VICENTE,LUIZ E.; PEREZ FILHO,ARCHIMEDES; PIQUEIRA,JOSÉ R.C..

ABSTRACT The Brazilian Cerrado is a vegetation mosaic composed of different physiognomies. Discussions remain open regarding the factors and processes responsible for the dynamic and spatial organization of the Cerrado - in its different physiognomies. The contributions of the complexity paradigm in this context are still less exploited, despite its great potential for explanations and predictions presented in previous diverse dynamic systems of complex behavior researches, a category in which the Cerrado can be included. This article has the intention of contributing to the construction of this new perspective, discussing - from theoretical concepts - the paradigm of complexity for the understanding of the organization and the dynamics of the Cerrado.

Population dynamics of Aphis gossypii Glover and in sole and intercropping systems of cotton and cowpea

Palavras-chave: Cerrado; Complexity; Complex system; Dynamics; Self-organized criticality.

Ano: 2016

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000602417

Anais da ABC (AABC)

FERNANDES,FRANCISCO S.; GODOY,WESLEY A.C.; RAMALHO,FRANCISCO S.; GARCIA,ADRIANO G.; SANTOS,BÁRBARA D.B.; MALAQUIAS,JOSÉ B..

ABSTRACT Population dynamics of aphids have been studied in sole and intercropping systems. These studies have required the use of more precise analytical tools in order to better understand patterns in quantitative data. Mathematical models are among the most important tools to explain the dynamics of insect populations. This study investigated the population dynamics of aphids Aphis gossypii and Aphis craccivora over time, using mathematical models composed of a set of differential equations as a helpful analytical tool to understand the population dynamics of aphids in arrangements of cotton and cowpea. The treatments were sole cotton, sole cowpea, and three arrangements of cotton intercropped with cowpea (t1, t2 and t3). The plants were infested with...