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Registros recuperados: 14
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An Empirical Evaluation of Poverty Mapping Methodology: Explicitly Spatial versus Implicitly Spatial Approach 31
Olivia, Susan; Gibson, John; Smith, Aaron D.; Rozelle, Scott; Deng, Xiangzheng.
Poverty maps provide information on the spatial distribution of welfare and can predict poverty levels for small geographic units like counties and townships. Typically regression methods are used to estimate coefficients from the detailed information in household surveys, which are then applied to the more extensive coverage of a census. One problem with standard regression techniques is that they do not take into account the ‗spatial dependencies‘ that often exist in the data. Ignoring spatial autocorrelation in the regression providing the coefficient estimates could lead to misleading predictions of poverty, and estimates of standard errors. Household survey data usually lack exact measures of location so it is not possible to fully account for this...
Tipo: Conference Paper or Presentation Palavras-chave: China; Poverty; Small Area Estimation; Survey Methods; Spatial Models.
Ano: 2009 URL: http://purl.umn.edu/47651
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Commodity Markets: Rational Expectations in Markets With Irrational Investors 31
Wong, Teddy T.; Smith, Aaron D..
The "financialization" of commodity markets have become a concern for policy makers and market participants. What was once a market for the hedging of holding physical commodities has expanded to become a market for the diversification of financial assets. When financial assets diversification goals are decoupled from the fundamental factors that affect producers and consumers of physical goods futures markets may not be as efficient in aggregating information concerning the economics of the underlying commodity. Theoretical understanding of whether commodity futures market function well under exogenous shifts in demand for futures contracts depend on our assumptions of how market participants behave, including their level of risk aversion. This paper...
Tipo: Working or Discussion Paper Palavras-chave: Commodity; Futures; Financialization; Competitive storage; Rational expectations; Agricultural and Food Policy; Agricultural Finance; Financial Economics; Risk and Uncertainty.
Ano: 2010 URL: http://purl.umn.edu/61526
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Computer and Internet Use by Great Plains Farmers 31
Smith, Aaron D.; Morrison Paul, Catherine J.; Goe, W. Richard; Kenney, Martin.
We use data from a 2001 survey of Great Plains farmers to explore the adoption, usage patterns, and perceived benefits of computers and the Internet. Our adoption results suggest that exposure to the technology through college, outside employment, friends, and family is ultimately more influential than farmer age and farm size. Notably, about half of those who use the Internet for farm-related business report zero economic benefits from it. Whether a farmer perceives that the Internet generates economic benefits depends primarily on how long the farmer has used the Internet for farm business and for what purposes.
Tipo: Working or Discussion Paper Palavras-chave: Farm Management; Research and Development/Tech Change/Emerging Technologies.
Ano: 2004 URL: http://purl.umn.edu/11947
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Computer and Internet Use by Great Plains Farmers 31
Smith, Aaron D.; Goe, W. Richard; Kemey, Martin; Morrison Paul, Catherine J..
This study uses data from a 2001 survey of Great Plains farmers to explore the adoption, usage patterns, and perceived benefits of computers and the Internet. Adoption results suggest that exposure to the technology through college, outside employment, friends, and family is ultimately more influential than farmer age and farm size. Notably, about half of those who use the Internet for farm-related business report zero economic benefits from it. Whether a farmer perceives that the Internet generates economic benefits depends primarily on how long the farmer has used the Internet for farm business and for what purposes.
Tipo: Journal Article Palavras-chave: Agriculture; Competitiveness; Net benefits; Technology adoption; Research and Development/Tech Change/Emerging Technologies.
Ano: 2004 URL: http://purl.umn.edu/30918
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Estimating the Market Effect of a Food Scare: The Case of Genetically Modified StarLink Corn 31
Carter, Colin A.; Smith, Aaron D..
Genetic modification of crops has revolutionized food production, but it remains controversial due to food safety and environmental concerns. A recent food safety scare provides a natural experiment on the corn market's willingness to accept unapproved genetically modified organisms. In 2000, a genetically modified corn variety called StarLink was discovered in the food-corn supply, even though it was not approved for human consumption. To estimate the price impact of this event, we develop the relative price of a substitute method, which applies not only to the StarLink event but also to rare events in other markets. We apply this method to measure the price impact of the StarLink contamination on the U.S. corn market. We find that the contamination led...
Tipo: Conference Paper or Presentation Palavras-chave: Food Consumption/Nutrition/Food Safety; Research and Development/Tech Change/Emerging Technologies; Q11; Q18; C22.
Ano: 2006 URL: http://purl.umn.edu/25447
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Forecasting in the Presence of Level Shifts 31
Smith, Aaron D..
This article addresses the problem of forecasting time series that are subject to level shifts. Processes with level shifts possess a nonlinear dependence structure. Using the stochastic permanent breaks (STOPBREAK) model, I model this nonlinearity in a direct and flexible way that avoids imposing a discrete regime structure. I apply this model to the rate of price inflation in the United States, which I show is subject to level shifts. These shifts significantly affect the accuracy of out-of-sample forecasts, causing models that assume covariance stationarity to be substantially biased. Models that do not assume covariance stationarity, such as the random walk, are unbiased but lack precision in periods without shifts. I show that the STOPBREAK model...
Tipo: Working or Discussion Paper Palavras-chave: Financial Economics; Research Methods/ Statistical Methods.
Ano: 2004 URL: http://purl.umn.edu/11985
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IMPACTS OF POLICY REFORMS ON THE SUPPLY OF MEXICAN LABOR TO U.S. FARMS: NEW EVIDENCE FROM MEXICO 31
Taylor, J. Edward; Boucher, Stephen R.; Smith, Aaron D.; Yunez-Naude, Antonio.
The availability of immigrant farmworkers from Mexico critically shapes fruit, vegetable, and horticultural (FVH) production in the United States. We test the impact of recent policy reforms on the supply of Mexican labor to U.S. farms, using a 2-way fixed effects model and new data from rural Mexico.
Tipo: Conference Paper or Presentation Palavras-chave: Labor and Human Capital.
Ano: 2004 URL: http://purl.umn.edu/19993
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Level Shifts and the Illusion of Long Memory in Economic Time Series 31
Smith, Aaron D..
When applied to time series processes containing occasional level shifts, the logperiodogram (GPH) estimator often erroneously finds long memory. For a stationary short-memory process with a slowly varying level, I show that the GPH estimator is substantially biased, and I derive an approximation to this bias. The asymptotic bias lies on the (0,1) interval, and its exact value depends on the ratio of the expected number of level shifts to a user-defined bandwidth parameter. Using this result, I formulate the Modified GPH estimator, which has a markedly lower bias. I illustrate this new estimator via applications to soybean prices and stock market volatility.
Tipo: Working or Discussion Paper Palavras-chave: Research Methods/ Statistical Methods.
Ano: 2004 URL: http://purl.umn.edu/11974
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Markov-Switching Model Selection Using Kullback-Leibler Divergence 31
Smith, Aaron D.; Naik, Prasad A.; Tsai, Chih-Ling.
In Markov-switching regression models, we use Kullback-Leibler (KL) divergence between the true and candidate models to select the number of states and variables simultaneously. In applying Akaike information criterion (AIC), which is an estimate of KL divergence, we find that AIC retains too many states and variables in the model. Hence, we derive a new information criterion, Markov switching criterion (MSC), which yields a marked improvement in state determination and variable selection because it imposes an appropriate penalty to mitigate the over-retention of states in the Markov chain. MSC performs well in Monte Carlo studies with single and multiple states, small and large samples, and low and high noise. Furthermore, it not only applies to...
Tipo: Working or Discussion Paper Palavras-chave: Research Methods/ Statistical Methods.
Ano: 2005 URL: http://purl.umn.edu/11976
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Partially Overlapping Time Series: A New Model for Volatility Dynamics in Commodity Futures 31
Smith, Aaron D..
In commodity futures markets, contracts with various delivery dates trade simultaneously. Applied researchers typically discard the majority of the data and form a single time series by choosing only one price observation per day. This strategy precludes a full understanding of these markets and can induce complicated nonlinear dynamics in the data. In this paper, I introduce the partially overlapping time series (POTS) model to model jointly all traded contracts. The POTS model incorporates time-to-delivery, storability, seasonality, and GARCH effects. I apply the POTS model to corn futures at the Chicago Board of Trade and the results uncover substantial inefficiency associated with delivery on corn futures. The results also support two theories of...
Tipo: Working or Discussion Paper Palavras-chave: Marketing.
Ano: 2004 URL: http://purl.umn.edu/11978
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Quantifying Obesity in Economic Research: How Misleading is the Body Mass Index? 31
Parks, Joanna C.; Smith, Aaron D.; Alston, Julian M..
Replaced with revised version of paper 07/19/10.
Tipo: Conference Paper or Presentation Palavras-chave: Obesity; Percent body fat (PBF); Body mass index (BMI); Economic costs; Measurement error; Health Economics and Policy; Research and Development/Tech Change/Emerging Technologies; C52; I10.
Ano: 2010 URL: http://purl.umn.edu/61841
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The Effects of the Food Stamp Program on Energy Balance and Obesity 31
Parks, Joanna C.; Smith, Aaron D.; Alston, Julian M..
The Food Stamp Program (FSP) administered by the U.S. Department of Agriculture (USDA) is the cornerstone of the U.S. federal income and food safety net policy. The FSP has subsidized the food budget for millions of American households for over forty years, spending more than $60 billion per year in recent times. Prior research has demonstrated that women who participate in the FSP are more likely to be overweight or obese than eligible non-participants. This finding raises the concern that the additional income provided by FSP benefits induces participants to eat significantly more calories and gain weight, contributing to the U.S. obesity epidemic. Previous studies of the FSP have yielded mixed results. In this study we develop new conceptual and...
Tipo: Conference Paper or Presentation Palavras-chave: Food Stamp Program (FSP); Supplemental Nutrition Assistance Program (SNAP); Obesity; Body mass index (BMI); Nutrition assistance; Agricultural and Food Policy; Food Consumption/Nutrition/Food Safety; Food Security and Poverty; Health Economics and Policy; Q18; H53; I12; I18; I38.
Ano: 2011 URL: http://purl.umn.edu/103537
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The Effects of the Food Stamp Program on Energy Balance and Obesity 31
Parks, Joanna C.; Smith, Aaron D.; Alston, Julian M..
The Effects of the Food Stamp Program on Energy Balance and Obesity
Tipo: Conference Paper or Presentation Palavras-chave: Food Stamp Program (FSP); Supplemental Nutrition Assistance Program (SNAP); Obesity; Body mass index (BMI); Nutrition assistance; Food Consumption/Nutrition/Food Safety; Q18; H53; I12; I18; I38.
Ano: 2011 URL: http://purl.umn.edu/100692
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The Market Effect of a Food Scare: The Case of Genetically Modified StarLink Corn 31
Carter, Colin A.; Smith, Aaron D..
Genetic modification of crops has revolutionized food production, but it remains controversial due to food safety concerns. A recent food safety scare provides a natural experiment on the market's willingness to accept an increase in perceived risk from genetically modified (GM) food. We analyze the market impact of contamination of the U.S. food-corn supply by a GM variety called StarLink. We find that the contamination led to a 6.8 percent discount in corn prices and that the suppression of prices lasted for at least a year.
Tipo: Working or Discussion Paper Palavras-chave: Food Consumption/Nutrition/Food Safety; Marketing.
Ano: 2004 URL: http://purl.umn.edu/11997
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