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	Provedor de dados Gayana Botánica (1) Autor Espejo,Jaime (1) Rodríguez,Roberto (1) Palavra-chave Conservación (1) Isla de Pascua (1) Sophora toromiro (1) Tipo do documento Journal article (1) Ano 2013 (1) País Chile (1) Idioma Espanhol (1)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 87 Primeira ... 1 2 3 4 5 ... Última Impact of global warming on Chinese wheat productivity AgEcon You, Liangzhi; Rosegrant, Mark W.; Fang, Cheng; Wood, Stanley. Climate change continues to have major impact on crop productivity all over the world. While many researchers have evaluated the possible impact of global warming on crop yields using mainly indirect crop simulation models, there are relatively few direct assessments on the impact of observed climate change on past crop yield and growth. We use a 1979-2000 Chinese crop-specific panel dataset to investigate the climate impact on Chinese wheat yield growth. We find that a 1 percent increase in wheat growing season temperature reduces wheat yields by about 0.3 percent. This negative impact is less severe than those reported in other regions. Rising temperature over the past two decades accounts for a 2.4 percent decline in wheat yields in China while the... Tipo: Working or Discussion Paper Palavras-chave: Global warming; Wheat yield; Production function; Marginal impact; Panel data; Climate; Wheat production; Crop Production/Industries; Environmental Economics and Policy. Ano: 2005 URL: http://purl.umn.edu/58588 The Interaction between Alcohol and Cigarette Consumption AgEcon Koksal, Aycan; Wohlgenant, Michael K.. It has long been recognized that cigarette and alcohol not only have adverse health effects, but also negative externalities imposed on third parties. If cigarette and alcohol are related in consumption, the information on the way in which they are related may allow a better coordination of the public policies concerning these goods. In this study, we use the expenditure data of a panel of US households to analyze the relation between cigarette and alcohol consumption in a rational addiction framework. We believe that individual level data would be a better tool to analyze addictive behavior as aggregate data might conceal much of micro behavior. We found that cigarettes and alcoholic beverages are substitutes. However, both cigarette and alcohol demand do... Tipo: Conference Paper or Presentation Palavras-chave: Rational addiction; Panel data; Cigarette consumption; Alcohol consumption; Demand and Price Analysis. Ano: 2010 URL: http://purl.umn.edu/61305 THE IMPACT OF MANURE PRODUCTION RIGHTS ON CAPITAL INVESTMENT IN THE DUTCH PIG SECTOR AgEcon Gardebroek, Cornelis. In this paper the effect of manure production rights on investment decisions of Dutch pig farmers is examined. A dynamic optimization model of investment that explicitly takes zero investments into account is augmented by a constraint on production arising from the introduction of manure production rights. In the theoretical model it is shown that such a constraint has a reducing effect on investment. The presence of this constraint is tested for using GMM structural break tests. The results provide evidence for the hypothesis that manure production rights have reduced investments through its effect on production. Tipo: Conference Paper or Presentation Palavras-chave: Investment; Manure production rights; Euler equation; GMM; Structural break testing; Panel data; Pig farms; Livestock Production/Industries. Ano: 2001 URL: http://purl.umn.edu/20490 What is it Consumers really want, and how can their preferences be influenced? The Case of fat in Milk AgEcon Andersen, Laura M.; Smed, Sinne. In this paper we investigate preferences for fat in milk through a structural characteristics model. The data includes information about daily purchases and social and demographic characteristics of more than 1,100 households. We find that consumers who prefer milk with a high fat content do not react to information about health effects, but can be influenced by prices, while consumers who prefer milk with a low share of fat are influenced by information, but are less price sensitive. Therefore, when attempting to decrease consumption of fat from milk, prices are more efficient than information. Tipo: Presentation Palavras-chave: Fat in milk; Characteristics model; Hedonic prices; Information; Panel data; Food Consumption/Nutrition/Food Safety; D12. Ano: 2012 URL: http://purl.umn.edu/122728 Industrial Coal Demand in China: A Provincial Analysis AgEcon Cattaneo, Cristina; Manera, Matteo; Scarpa, Elisa. In recent years, concerns regarding the environmental implications of the rising coal demand have induced considerable efforts to generate long-term forecasts of China’s energy requirements. Nevertheless, none of the previous empirical studies on energy demand for China has tackled the issue of modelling coal demand in China at provincial level. The aim of this paper is to fill this gap. In particular, we model and forecast the Chinese demand for coal using time series data disaggregated by provinces. Moreover, not only does our analysis account for heterogeneity among provinces, but also, given the nature of the data, it captures the presence of spatial autocorrelation among provinces using a spatial econometric model. A fixed effects spatial lag model... Tipo: Working or Discussion Paper Palavras-chave: Energy demand; Coal demand; China; Spatial econometrics; Panel data; Forecasting; Resource /Energy Economics and Policy; C23; E6; Q31; Q41. Ano: 2008 URL: http://purl.umn.edu/44425 Discussion: Applications and Innovations in Spatial Econometrics AgEcon LeSage, James P.. These articles provide a discussion of studies presented in a session on spatial econometrics, focusing on the ability of spatial regression models to quantify the magnitude of spatial spillover impacts. Both articles presented argue that a proper modeling of spatial spillovers is required to truly understand the phenomena under study, in one case the impact of climate change on land values (or crop yields) and in the second the role of regional industry composition on regional business establishment growth. Tipo: Journal Article Palavras-chave: Lagged variables; Panel data; Spatial spillovers; Community/Rural/Urban Development; Environmental Economics and Policy; Resource /Energy Economics and Policy; C33; C51. Ano: 2011 URL: http://purl.umn.edu/113519 The Impact of Weather Extremes on Agricultural Production Methods: Does Drought Increase Adoption of Conservation Tillage Practices? AgEcon Ding, Ya; Schoengold, Karina; Tadesse, Tsegaye. The paper combines panel data techniques with spatial analysis to measure the impact of extreme weather events on the adoption of conservation tillage. Zellner’s SUR technique is extended to spatial panel data to correct for cross-sectional heterogeneity, spatial autocorrelation, and contemporaneous correlation. Panel data allow the identification of differences in adoption rates. The adoption of no-till, other conservation tillage, and reduced-till are estimated relative to conventional tillage. Extremely dry conditions in recent years increase the adoption of other conservation tillage practices, while spring floods in the year of production reduce the use of no-till practices. Tipo: Journal Article Palavras-chave: Conservation tillage; Drought; Panel data; Technology adoption; Weather extremes; Crop Production/Industries. Ano: 2009 URL: http://purl.umn.edu/57631 Do Private Labels Generate Loyalty? Empirical Evidence for German Frozen Pizza AgEcon Wettstein, Nadine; Brosig, Stephan; Glauben, Thomas; Hanf, Jon Henrich; Loy, Jens-Peter. www.ifama.org Tipo: Journal Article Palavras-chave: Food retailing; Private labels; Brand loyalty; Panel data; Hazard analysis; Consumer/Household Economics; Demand and Price Analysis; Institutional and Behavioral Economics; Marketing. Ano: 2009 URL: http://purl.umn.edu/92572 Effect of infrastructure investments on total factor productivity (TFP) in Brazilian agriculture AgEcon Mendes, Sergio Magno; Teixeira, Erly Cardoso; Salvato, Marcio Antonio. Since the 1980s, the investments in infrastructure have been significantly reduced, jeopardizing Total Factor Productivity (TFP) and competitiveness of Brazilian agriculture. The Solow growth model with panel data is used to estimate TFP. An adaptation of the Zhang and Fan (2004) model for India, using the Generalized Method of Moments (GMM), is applied to study the effects of infrastructure investments on TFP. The lack of such investments in Brazil caused the effects to be larger and with lag periods smaller than in other countries. These investments affect TFP in the first years, and the study suggests that the return occurs in the period from zero to two years. Among the analyzed infrastructure elements, investments in roads have the greatest impact on... Tipo: Conference Paper or Presentation Palavras-chave: Infrastructure investments; TFP; Agriculture; Panel data; GMM; International Development; Productivity Analysis. Ano: 2009 URL: http://purl.umn.edu/50777 PANEL STRATIFICATION IN META-ANALYSIS OF ECONOMIC STUDIES: AN INVESTIGATION OF ITS EFFECTS IN THE RECREATION VALUATION LITERATURE AgEcon Rosenberger, Randall S.; Loomis, John B.. Statistical summarizations of literature review databases using meta-regression analysis provide insight into the differences in past estimates of economic variables such as benefits and price elasticities. The panel nature of the data is an issue that has not received adequate attention in past meta-analyses. This paper conceptually and empirically explores the complexity of stratifying data into panels that model the potential correlation and heterogeneity of past outdoor recreation benefit research. Although our tests of three stratifications of the data did not discern panel effects, the inherent complexity of the data maintains a strong presumption of heterogeneous strata. Tipo: Journal Article Palavras-chave: Meta-analysis; Outdoor recreation economic benefits; Panel data; Stratification; Resource /Energy Economics and Policy. Ano: 2000 URL: http://purl.umn.edu/15310 Econometric Analysis of the Effects of Subsidies on Farm Production in Case of Endogenous Input Quantities AgEcon Henningsen, Arne; Kumbhakar, Subal C.; Lien, Gudbrand D.. Replaced with revised version of paper 07/29/09. Tipo: Conference Paper or Presentation Palavras-chave: Panel data; Subsidies; Household model; Endogeneity; Norwegian grain farming; Agricultural and Food Policy; Consumer/Household Economics; Production Economics. Ano: 2009 URL: http://purl.umn.edu/49728 Testing for serial correlation in linear panel-data models AgEcon Drukker, David M.. Because serial correlation in linear panel-data models biases the standard errors and causes the results to be less efficient, researchers need to identify serial correlation in the idiosyncratic error term in a panel-data model. A new test for serial correlation in random- or fixed-effects one-way models derived by Wooldridge (2002) is attractive because it can be applied under general conditions and is easy to implement. This paper presents simulation evidence that the new Wooldridge test has good size and power properties in reasonably sized samples. Tipo: Journal Article Palavras-chave: Panel data; Serial correlation; Specification tests; Research Methods/ Statistical Methods. Ano: 2003 URL: http://purl.umn.edu/116069 Combating chronic poverty in Uganda: towards a new strategy AgEcon Ssewanyana, Sarah N.. Using a panel of 3,572 households in the Northern Uganda Social Action Fund (NUSAF) region interviewed in 2004 and in 2008, the paper provides new evidence on chronic poverty in Uganda. While progress in reducing poverty rates has been impressive from 64.6 percent to 52.2 percent, the levels remain high with a significant number of persistently poor households. Four in every ten households are chronically poor of which 44.9 percent are living in extreme chronic poverty. About 37.8 percent of the households are living in transient poverty of which 67.4 percent escaped poverty during the panel period. The substantial movements out of poverty can perhaps be explained largely by the relative return of peace in the region that enabled households to engage in... Tipo: Report Palavras-chave: Chronic poverty; Poverty dynamics; Panel data; Uganda; Northern Uganda; EPRC; Community/Rural/Urban Development; Consumer/Household Economics; Crop Production/Industries; Food Security and Poverty. Ano: 2010 URL: http://purl.umn.edu/101713 Precio de la tierra con presión urbana: un modelo para España AgEcon Decimavilla, Esther; San Juan, Carlos; Sperlich, Stefan. RESUMEN: Estudiamos el precio de la tierra para uso agrario y las variables que determinan su evolución en España, tratando de identificar qué parte de la subida de precios observada se justifica por elementos «internos», relacionados con la renta agraria esperada, y cuál proviene de elementos externos o especulativos, vinculados a cambios en el uso del suelo. Además se relaciona el ciclo de precios con la aceleración de la especialización en el ámbito regional y la integración en la PAC. La novedad de este trabajo consiste en identificar, mediante técnicas de datos de panel, factores no fundamentales (presión urbanizadora, creación de regadíos, cambio demográfico) que, además de los fundamentales (ingresos esperados y localización geográfica) determinan... Tipo: Journal Article Palavras-chave: Especialización regional; Especulación urbana; Datos de panel; Precios de la tierra; Productividad agraria; Urban pressure; Panel data; Land prices; Agricultural productivity; Regional specialization; Agribusiness; Agricultural and Food Policy; Community/Rural/Urban Development; Demand and Price Analysis; Environmental Economics and Policy; Land Economics/Use; Research Methods/ Statistical Methods; Q15; R14; Q24; R52. Ano: 2008 URL: http://purl.umn.edu/37186 Estimation and testing of fixed-effect panel-data systems AgEcon Blackwell, J. Lloyd, III. This paper describes how to specify, estimate, and test multiple-equation, fixed-effect, panel-data equations in Stata. By specifying the system of equations as seemingly unrelated regressions, Stata panel-data procedures worked seamlessly for estimation and testing of individual variable coefficients, but additional routines using test were needed for testing of individual equations and differences between equations. Tipo: Journal Article Palavras-chave: Panel data; Fixed effect; Multiple equations; Seemingly unrelated regressions; Heteroskedasticity; Autocorrelation; Contemporaneous correlation; Tests of linear combinations; Research Methods/ Statistical Methods. Ano: 2005 URL: http://purl.umn.edu/117512 Panel Data Estimation Techniques for Farm-level Data Model AgEcon Platoni, Silvia; Sckokai, Paolo; Moro, Daniele. Econometric models wishing to estimate relevant parameters for agricultural policy analysis are increasingly relying on unbalanced panels of farm-level data. Since in the agricultural economics literature such models have often been estimated through simplified approaches, in this paper we try to verify whether the adoption of more sophisticated panel data techniques may impact the estimation results. For this reason, the policy model by Moro and Sckokai (1999) has been reestimated using techniques recently developed in the econometric literature. The preliminary results show a strong impact on the estimations. This seems to suggest that the adoption of proper panel-data techniques is likely to be very important in order to obtain reliable estimates of... Tipo: Conference Paper or Presentation Palavras-chave: Agricultural policy; Panel data; Systems of equations; Agricultural and Food Policy. Ano: 2008 URL: http://purl.umn.edu/44268 PANEL DATA DOUBLE-HURDLE MODEL: AN APPLICATION TO DAIRY ADVERTISING AgEcon Dong, Diansheng; Chung, Chanjin; Kaiser, Harry M.. In this study, we extend to panel data structures the double-hurdle model typically used in cross-sectional data. The new double-hurdle model can account not only for the censored nature of commodity purchases, but also for the dynamics of the purchase process. In this model, a flexible error structure is assumed to account for state dependence and household-specific heterogeneity. In the empirical application for milk purchase, we find that generic advertising increases the probability of market participation as well as the purchase quantity and incidence. Temporal dependence is also found in both purchase and participation equations. Tipo: Conference Paper or Presentation Palavras-chave: Double-hurdle model; Panel data; Household purchase; Milk; Advertising; Heterogeneity; State dependence; Simulated maximum likelihood; Marketing. Ano: 2001 URL: http://purl.umn.edu/20502 Reliable estimation of generalized linear mixed models using adaptive quadrature AgEcon Rabe-Hesketh, Sophia; Skrondal, Anders; Pickles, Andrew. Generalized linear mixed models or multilevel regression models have become increasingly popular. Several methods have been proposed for estimating such models. However, to date there is no single method that can be assumed to work well in all circumstances in terms of both parameter recovery and computational efficiency. Stata’s xt commands for two-level generalized linear mixed models (e.g., xtlogit) employ Gauss–Hermite quadrature to evaluate and maximize the marginal log likelihood. The method generally works very well, and often better than common contenders such as MQL and PQL, but there are cases where quadrature performs poorly. Adaptive quadrature has been suggested to overcome these problems in the two-level case. We have recently implemented a... Tipo: Journal Article Palavras-chave: Adaptive quadrature; Gllamm; Generalized linear mixed models; Random-effects models; Panel data; Numerical integration; Adaptive integration; Multilevel models; Clustered data; Research Methods/ Statistical Methods. Ano: 2002 URL: http://purl.umn.edu/115947 Effect of infrastructure investments on total factor productivity (TFP) in Brazilian agriculture AgEcon Mendes, Sergio Magno; Teixeira, Erly Cardoso; Salvato, Marcio Antonio. Since the 1980s, the investments in infrastructure have been significantly reduced, jeopardizing Total Factor Productivity (TFP) and competitiveness of Brazilian agriculture. The Solow growth model with panel data is used to estimate TFP. An adaptation of the Zhang and Fan (2004) model for India, using the Generalized Method of Moments (GMM), is applied to study the effects of infrastructure investments on TFP. The lack of such investments in Brazil caused the effects to be larger and with lag periods smaller than in other countries. These investments affect TFP in the first years, and the study suggests that the return occurs in the period from zero to two years. Among the analyzed infrastructure elements, investments in roads have the greatest impact on... Tipo: Working or Discussion Paper Palavras-chave: Infrastructure investments; TFP; Agriculture; Panel data; GMM; Agricultural and Food Policy; Public Economics. Ano: 2008 URL: http://purl.umn.edu/53441 Combining mixed logit models and random effects models to identify the determinants of willingness to pay for rural landscape improvements AgEcon Campbell, Danny. This paper reports the findings from a discrete choice experiment study designed to estimate the economic benefits associated with rural landscape improvements in Ireland. Using a mixed logit model, the panel nature of the dataset is exploited to retrieve willingness to pay values for every individual in the sample. This departs from customary approaches in which the willingness to pay estimates are normally expressed as measures of central tendency of an a priori distribution. In a different vein from analysis conducted in previous discrete choice experiment studies, this paper uses random effects models for panel data to identify the determinants of the individual-specific willingness to pay estimates. In comparison with the standard methods used to... Tipo: Conference Paper or Presentation Palavras-chave: Agri-environment; Discrete choice experiments; Mixed logit; Panel data; Random effects; Willingness to pay; Demand and Price Analysis; Environmental Economics and Policy; C33; C35; Q24; Q51. Ano: 2007 URL: http://purl.umn.edu/7975 Registros recuperados: 87 Primeira ... 1 2 3 4 5 ... Última

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