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Registros recuperados: 29
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A Globally Flexible Model for Crop Yields Under Weather Risk AgEcon
Cooper, Joseph C.; Wallander, Steven.
The literature on climate change and crop yields recognizes the need to allow for highly non-linear marginal effects. This study combines these two areas of the literature by using Flexible Fourier Transforms (FFT’s) to ensure flexibility for both the time trend and the weather effects. This study also illustrates how FFT’s can be combined with quantile regression (QR) to provide both robustness to outliers and information on the scale effects of time and weather variables. For U.S. county level data on corn, soybeans, and winter wheat, we estimate the relationship between yield and temperature and precipitation using a traditional parametric expected-yield estimator, our quantile-FFT regression evaluated at the median, and our QR-FFT regression that...
Tipo: Conference Paper or Presentation Palavras-chave: Crop yield distributions; Flexible fourier transforms; Quantile regression; Crop Production/Industries; Risk and Uncertainty.
Ano: 2010 URL: http://purl.umn.edu/103560
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A two-stage productivity analysis using bootstrapped Malmquist index and quantile regression AgEcon
Kaditi, Eleni A.; Nitsi, Elisavet I..
This paper examines the effects of farm characteristics and government policies in enhancing productivity growth for a sample of Greek farms, using a two-stage procedure. In the 1st-stage, non-parametric estimates of Malmquist index and its decompositions are computed, while a bootstrapping procedure is applied to provide their statistical precision. In the 2nd-stage, the productivity growth estimates are regressed on various covariates using a bootstrapped quantile regression approach. The effect that the covariates exert on productivity growth of the average producer is analyzed, as well as the marginal effect of a given covariate for individuals at different points in the conditional productivity distribution. The results indicate that there exists...
Tipo: Conference Paper or Presentation Palavras-chave: Malmquist productivity index; Quantile regression; Bootstrap; Research Methods/ Statistical Methods; C14; C21; D24.
Ano: 2009 URL: http://purl.umn.edu/52845
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Agglomeration, Spatial Interaction and Convergence in the EU AgEcon
Brauninger, Michael; Niebuhr, Annekatrin.
We investigate the convergence process among EU regions between 1980-2002 taking into account the effects of spatial heterogeneity and spatial spillover effects. The spatial regimes model allows for different steady-state growth paths. In contrast to previous analyses, the regimes in this paper refer to spatial categories, i.e. we assume that agglomerations, urbanised and rural regions are characterised by group-specific steadystates. Moreover, the regression analysis considers the effects of interaction among neighbouring regions, possibly leading to a spatial dependence of regional growth rates. We check whether spatial dependence is caused by spatial spillovers or based on country effects.
Tipo: Working or Discussion Paper Palavras-chave: Convergence; Agglomeration; European Union; Spatial econometrics; Quantile regression; International Development; C21; O52; R11.
Ano: 2005 URL: http://purl.umn.edu/26150
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Analyzing the Determinants of Technical Efficiency Among Traditional Dairy Farms in Wisconsin: A Quantile Regression Approach AgEcon
Chidmi, Benaissa; Solis, Daniel; Funtanilla, Margil; Cabrera, Victor E..
This study analyzes the determinants of TE among traditional dairy farms in the State of Wisconsin taking into account dairy farms’ heterogeneity. To do so, we first estimate a production frontier and the level of TE using the SPF framework. Then we analyze the determinants of TI using a quantile regression analysis. The results indicate that the determinants of TE affect in very specific ways farmers with different levels of TE. This result confirms our hypothesis on the importance of controlling for farm heterogeneity when analyzing the determinants of TE. This issue is also important from an empirical point of view. Policy makers could improve the effectiveness of their work by targeting specific agricultural services and aid designed for farmers with...
Tipo: Conference Paper or Presentation Palavras-chave: Technical efficiency; Dairy; Quantile regression; Agribusiness; Agricultural and Food Policy; Marketing; Production Economics; Productivity Analysis.
Ano: 2010 URL: http://purl.umn.edu/61320
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Changes in Fruit and Vegetable Consumption over Time and across Regions in China: A Difference-in-Differences Analysis with Quantile Regression AgEcon
Liu, Kang Ernest; Chang, Hung-Hao; Chern, Wen S..
Recently, there has been considerable interest in estimating food demand structure in China due to its huge market for food products. Previous literature has focused on the primary food products such as grains and meats, but studies on fruits and vegetables are limited. To fulfill this gap, this paper investigates the changes of fruit and vegetable consumption in Chinese urban households between 1993 and 2001. In this study, we use the difference-in-differences method with quantile regression to demonstrate how these changes of fruit and vegetable consumption over time may differ across regions. Additionally, how these changes may differ over the entire distribution. Using household survey data from 1993 and 2001 of three selected provinces, our results...
Tipo: Conference Paper or Presentation Palavras-chave: Fruit and vegetable consumption; China; Inequality; Quantile regression; Difference-in-differences model.; Food Consumption/Nutrition/Food Safety.
Ano: 2008 URL: http://purl.umn.edu/6531
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Does Gibrat's Law Hold Amongst Dairy Farmers in Northern Ireland? AgEcon
Kostov, Philip; Patton, Myles; Moss, Joan E.; McErlean, Seamus.
This paper tests whether the Law of Proportionate Effects (Gibrat, 1931), which states that farms grow at a rate that is independent of their size, holds for the dairy farms in Northern Ireland. Previous studies have tended to concentrate on testing whether the law holds for all farms. The methodology used in this study permits investigation of whether the law holds for some farms or all farms according to their size. The approach used avoids the subjective splitting of samples, which tends to bias results. The finding shows that the Gibrat law does hold except in the case of small farms. This is in accordance with previous findings that Gibrat's law tends to hold when only larger farms are considered, but tends to fail when smaller farms are included in...
Tipo: Conference Paper or Presentation Palavras-chave: Gibrat's law; Quantile regression; Sample selection bias; Integrated Conditional Moments test; Agricultural and Food Policy; C12; C14; O49; Q19.
Ano: 2005 URL: http://purl.umn.edu/24775
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Export Intensity and Plant Characteristics: What Can We Learn from Quantile Regression? AgEcon
Wagner, Joachim.
Using quantile regression and a rich cross section data set for German manufacturing plants this paper documents that the impact of plant characteristics on export activities varies along the conditional size distribution of the export/sales ratio.
Tipo: Working or Discussion Paper Palavras-chave: Exports; Quantile regression; Heterogeneous firms; International Relations/Trade; F10; D21; L60.
Ano: 2004 URL: http://purl.umn.edu/26390
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Factors Affecting the Macronutrient Intake of U.S. Adults AgEcon
Variyam, Jayachandran N..
The purpose of this study is to better characterize factors associated with the likelihood of macronutrient excess or inadequacy among U.S adults by modeling parts of the conditional distribution of dietary intakes other than the conditional mean. The risk of dietary inadequacy or excess faced by an individual tends to increase as his or her intake moves from the mean of a nutrient intake distribution toward its tails. Therefore, marginal effects of explanatory variables estimated at the conditional mean using ordinary least squares may be of limited value in characterizing these distributions. Quantile regression is effective in this situation since it can estimate conditional functions at any part of the distribution. Quantile regressions based on data...
Tipo: Working or Discussion Paper Palavras-chave: Diet quality; Health risk; Heteroskedasticity; Nutrition; Quantile regression; Food Consumption/Nutrition/Food Safety.
Ano: 2003 URL: http://purl.umn.edu/33572
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Financial Management and Portfolio Analysis for U.S. Farm and Nonfarm Households AgEcon
Katchova, Ani L..
This study examines the portfolio allocation of assets for farm and nonfarm households using the Agricultural Resource Management Survey and the Survey of Consumer Finances. The stylized facts of household finance, including limited participation in equity markets and heterogeneity of asset portfolios, are also confirmed for farm households. However, farm households show fewer differences in participation rates and asset allocation across wealth groups. Probit and conditional regression models indicate that fewer demographic factors affect participation rates and portfolio shares of risky assets for farm than nonfarm households. The aggregate statistics seem overwhelmingly influenced by households with large holdings of risky assets as shown by quantile...
Tipo: Journal Article Palavras-chave: Farm households; Financial management; Nonfarm households; Portfolio analysis; Quantile regression; Agricultural Finance; Financial Economics.
Ano: 2008 URL: http://purl.umn.edu/48143
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Food Security and Wheat Prices in Afghanistan: A Distribution-sensitive Analysis of Household-level Impacts AgEcon
D'Souza, Anna; Jolliffe, Dean.
Replaced with revised version of paper 07/29/11.
Tipo: Conference Paper or Presentation Palavras-chave: Afghanistan; Food prices; Wheat; Food security; Nutrition; Poverty; Quantile regression; Influence functions; Consumer/Household Economics; Food Consumption/Nutrition/Food Safety; Food Security and Poverty; D12; I3.
Ano: 2011 URL: http://purl.umn.edu/103443
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GIBRAT'S LAW REVISITED IN A TRANSITION ECONOMY. THE HUNGARIAN CASE AgEcon
Bakucs, Lajos Zoltan; Ferto, Imre.
The paper investigates the validity of Gibrat's Law in Hungarian agriculture. Employing various specifications including OLS, two-step Heckman model and quantile regressions our results strongly reject Gibrat’s Law for full sample. Estimations suggest that small farms tend to grow faster than larger ones. However, splitting the sample into two subgroups (corporate and family farms) we found different results. For family farms however, only OLS regression results reject Gibrat's Law, whilst the two-step Heckman models and quantile regression estimates support it. Finally, for corporate farms our results support the Law regardless of the method or size measure used. Our results indicate that there is no difference between family farms and corporate farms...
Tipo: Conference Paper or Presentation Palavras-chave: Gibrat's Law; Selection bias; Quantile regression; Transition agriculture; Farm Management; Research Methods/ Statistical Methods.
Ano: 2007 URL: http://purl.umn.edu/7813
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Global marine primary production constrains fisheries catches ArchiMer
Chassot, Emmanuel; Bonhommeau, Sylvain; Dulvy, Nicholas K.; Melin, Frederic; Watson, Reg; Gascuel, Didier; Le Pape, Olivier.
Primary production must constrain the amount of fish and invertebrates available to expanding fisheries; however the degree of limitation has only been demonstrated at regional scales to date. Here we show that phytoplanktonic primary production, estimated from an ocean-colour satellite (SeaWiFS), is related to global fisheries catches at the scale of Large Marine Ecosystems, while accounting for temperature and ecological factors such as ecosystem size and type, species richness, animal body size, and the degree and nature of fisheries exploitation. Indeed we show that global fisheries catches since 1950 have been increasingly constrained by the amount of primary production. The primary production appropriated by current global fisheries is 17-112% higher...
Tipo: Text Palavras-chave: Bottom-up; Large Marine Ecosystem; Quantile regression; Sustainable fishing.
Ano: 2010 URL: http://archimer.ifremer.fr/doc/00002/11294/7836.pdf
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Impact of Off-farm Income on Farm Efficiency in Slovenia AgEcon
Bojnec, Stefan; Ferto, Imre.
The paper investigates the impact of off-farm income on farm technical efficiency for the Slovenian Farm Accountancy Data Network farms in the years 2004-2008. Farm stochastic frontier time-varying decay inefficiency is positively associated with total utilised agricultural areas and total labour input, and vice versa with intermediate consumption and fixed assets. We find a positive association between farm technical efficiency and the off-farm income. Farm technical efficiency has increased steadily over time, the process, which was led by the off-farm spill over effect and most efficient farms. Farm technical efficiency is also positively associated with economic farm size, while association with subsidies is mixed depending on the estimation procedure....
Tipo: Conference Paper or Presentation Palavras-chave: Off-farm income; Stochastic frontier analysis; Panel regression; Quantile regression; Slovenia; Farm Management.
Ano: 2011 URL: http://purl.umn.edu/108945
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Impact of Off-farm Income on Farm Efficiency in Slovenia AgEcon
Bojnec, Stefan; Ferto, Imre.
Impact of Off-farm Income on Farm Efficiency in Slovenia
Tipo: Conference Paper or Presentation Palavras-chave: Off-farm income; Stochastic frontier analysis; Panel regression; Quantile regression; Slovenia; Agricultural Finance; Farm Management.
Ano: 2011 URL: http://purl.umn.edu/114258
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New developments in fruit and vegetables consumption in the period 1999-2004 in Denmark - A quantile regression approach AgEcon
Hansen, Aslak H..
The development in the consumption of fruit and vegetables in the period 1999-2004 in Denmark was investigated using quantile regression and two previously overlooked problems were identified. First, the change in the ten percent quantile samples decreased. This could have been caused by changes in the distribution of covariates. Therefore, the counterfactual decomposition of Machado and Mata (2005) was used and the methodology established that the change was not caused by alterations in the distribution of covariates but by changes in the coefficients and therefore a change in behaviour. The reason for this development is probably due to low income groups becoming relatively more income constrained since the gap to the high income group have grown...
Tipo: Conference Paper or Presentation Palavras-chave: Quantile regression; Counterfactual decomposition; Expenditure distribution; Food Consumption/Nutrition/Food Safety.
Ano: 2008 URL: http://purl.umn.edu/44190
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Nonlinear quantile regression to describe the dry matter accumulation of garlic plants Ciência Rural
Puiatti,Guilherme Alves; Cecon,Paulo Roberto; Nascimento,Moysés; Nascimento,Ana Carolina Campana; Carneiro,Antônio Policarpo Souza; Silva,Fabyano Fonseca e; Puiatti,Mário; Cruz,Cosme Damião.
ABSTRACT: The objective of this study was to adjust nonlinear quantile regression models for the study of dry matter accumulation in garlic plants over time, and to compare them to models fitted by the ordinary least squares method. The total dry matter of nine garlic accessions belonging to the Vegetable Germplasm Bank of Universidade Federal de Viçosa (BGH/UFV) was measured in four stages (60, 90, 120 and 150 days after planting), and those values were used for the nonlinear regression models fitting. For each accession, there was an adjustment of one model of quantile regression (τ=0.5) and one based on the least squares method. The nonlinear regression model fitted was the Logistic. The Akaike Information Criterion was used to evaluate the goodness of...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Quantile regression; Nonlinear regression; Allium sativum L.; Growth rate; Cluster analysis..
Ano: 2020 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782020000100203
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Public Policies and the Demand for Carbonated Soft Drinks: A Censored Quantile Regression Approach AgEcon
Gustavsen, Geir Waehler.
Heavy consumption of soda may contribute to obesity, strokes, and cardiac problems. From a health perspective, the distribution of the consumption is at least as important as the mean. Censored as well as ordinary quantile regression techniques were used to estimate the demand for sugary soda based on household data from 1989 to 1999. It was found that heavy drinkers are more price- and expenditure-responsive than are light drinkers. The study shows that increasing the taxes on carbonated soft drinks will lead to a small reduction in consumption for small and moderate consumers and a huge reduction for heavy consumers.
Tipo: Conference Paper or Presentation Palavras-chave: Soda demand; Quantile regression; Taxes; Agricultural and Food Policy; Food Consumption/Nutrition/Food Safety; D12; I10.
Ano: 2005 URL: http://purl.umn.edu/24737
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Quantile regression of nonlinear models to describe different levels of dry matter accumulation in garlic plants Ciência Rural
Puiatti,Guilherme Alves; Cecon,Paulo Roberto; Nascimento,Moysés; Nascimento,Ana Carolina Campana; Carneiro,Antônio Policarpo Souza; Silva,Fabyano Fonseca e; Puiatti,Mário; Oliveira,Ana Carolina Ribeiro de.
ABSTRACT: Plant growth analyses are important because they generate information on the demand and necessary care for each development stage of a plant. Nonlinear regression models are appropriate for the description of curves of growth, since they include parameters with practical biological interpretation. However, these models present information in terms of the conditional mean, and they are subject to problems in the adjustment caused by possible outliers or asymmetry in the distribution of the data. Quantile regression can solve these problems, and it allows the estimation of different quantiles, generating more complete and robust results. The objective of this research was to adjust a nonlinear quantile regression model for the study of dry matter...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Quantile regression; Nonlinear regression; Dry matter; Allium sativum L.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782018000100203
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Suitable habitats of fish species in the Barents Sea ArchiMer
Husson, Berengere; Certain, Gregoire; Filin, Anatoly; Planque, Benjamin.
Many marine species are shifting their distribution poleward in response to climate change. The Barents Sea, as a doorstep to the fast-warming Arctic, is experiencing large scale changes in its environment and its communities. This paper aims at understanding what environmental predictors limit fish species habitats in the Barents Sea and discuss their possible evolution in response to the warming of the Arctic. Species distribution models usually aim at predicting the probability of presence or the average abundance of a species, conditional on environmental drivers. A complementary approach is to determine suitable habitats by modelling the upper limit of a species’ response to environmental factors. Using quantile regressions, we model the upper limit...
Tipo: Text Palavras-chave: Quantile regression; Habitat suitability models; Climate change; Species distribution; Species shifts; Environmental drivers.
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00605/71682/70120.pdf
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Survival and Growth of Family Farms in a Transition Country – The Hungarian Case AgEcon
Bakucs, Lajos Zoltan; Ferto, Imre.
The paper investigates the validity of Gibrat’s Law in Hungarian agriculture. We use FADN data between 2001 and 2007 and employ quantile regression techniques to test the validity of Gibrat’s Law across quantiles. The Law is strongly rejected for all quantiles, providing strong evidence that smaller farms tend to grow faster than larger ones. We provide a number of socio-economic factors that can explain farm growth. Of these we found that total subsidies received by farm and far operator’s age are the most significant factors.
Tipo: Conference Paper or Presentation Palavras-chave: Gibrat’s Law; Family farm; Quantile regression; Transition agriculture; Community/Rural/Urban Development; Consumer/Household Economics; P32; Q12; Q19.
Ano: 2009 URL: http://purl.umn.edu/52846
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