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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Essays on complementarity : organizational and market changes in agriculture / Essais sur la complémentarité : changements organisationnels et de marché en agriculture

Raza, Saqlain 29 January 2014 (has links)
Cette thèse vise à tester pour l’existence d’effet de complémentarités entre différentes activités économiques dans le secteur agricole. Pour cela, nous mobilisons les deux approches que proposent la littérature, à savoir l’approche par la productivité et l’approche par l’adoption. Nous commençons par une revue de la littérature sur l’économie de la complémentarité, en nous focalisant sur ces deux approches de la complémentarité et ses modèles empiriques. Nous proposons ensuite trois analyses empiriques permettant de tester ces modèles. La première explore les déterminants du choix de marque et/ou de signes des qualité par les petites coopératives agricoles françaises, avec un focus particulier sur la coexistence de ces deux signes. La seconde fournit un test direct de complémentarité entre labels et marques en recourant à l’approche par l’adoption. En estimant un probit multinomial, il est en effet possible de séparer l’effet de complémentarité de celui de l’hétérogénéité inobservable. La troisième introduit l’approche par la productivité, en sus de l’approche par l’adoption, pour tester de cet eet de complémentarité dans les systèmes de polyculture élevage adoptés par les petits exploitants de la province du Pendjab au Pakistan. / The main objective of this thesis is to test for complementarity between different economic activities in agriculture. To do this, we have recourse to the two approaches proposed by the literature, i.e. the productivity approach and the adoption approach. First, we review the economics of complementarity and analyze the different empirical models to test for complementarity. Then, we propose three empirical analyses testing these models. The first examine closely the drivers of the branding and labeling strategies from French small agricultural co-operatives, with a focus on the coexistence of both quality signals. The second directly test for complementarity between branding and labeling using the adoption approach, by estimating a multinomal probit. This allow us to separate what is really due to complementarity and what is caused by unobserved heterogeneity. Third, in addition to adoption approach, we test for complementarity using a productivity approach in the mixed farming systems adopted by smallholder farmers in Punjab, Pakistan.
102

Não são só 20 centavos: efeitos sobre o tráfego da Região Metropolitana de São Paulo devido a redução na tarifa de ônibus financiada pelo aumento da CIDE nos combustíveis da cidade de São Paulo / It is not only 20 cents: effects on traffic in the Metropolitan Region of São Paulo due to reduction in bus fare financed by increased fuel tax in São Paulo city

Barcellos, Thaís Mendonça 26 June 2014 (has links)
Em junho de 2013, o reajuste de R$ 0,20 na tarifa de ônibus gerou uma série de manifestações populares no país que acabaram fazendo alguns governos, como o da cidade de São Paulo, voltarem atrás e arcarem com essa diferença com as empresas de ônibus. Visto isso, o prefeito de São Paulo, Fernando Haddad, propôs uma política de municipalização de um tributo imposto sobre a gasolina, a CIDE, para financiar o transporte público urbano. Nesse contexto, foi encomendada uma pesquisa a Fundação Getúlio Vargas para responder a magnitude do impacto desse subsídio cruzado entre usuários do transporte privado e coletivo. Esse trabalho utiliza o resultado encontrado por essa pesquisa para responder qual o efeito sobre o tráfego da Região Metropolitana de São Paulo utilizando dados da Pesquisa de Origem e Destino de 2007. Os resultados encontrados mostram que a política de subsídio cruzado proporciona um baixo deslocamento no fluxo dos modos de transporte. Além disso, a análise de bem estar da política mostra que os mais favorecidos são os indivíduos de baixa renda. A estimação é feita com base em dois modelos de escolha discreta (Multinomial e Mixed Logit), separada por dois motivos de viagem: trabalho e estudo. E, as simulações de deslocamento de demanda utilizam dois valores de tributos, R$ 0,10 e R$ 0,50. / In June 2013, the increase of 0.20 BRL in bus fare has emerged a series of popular demonstrations in the country that ended up making some governments, such as the city of São Paulo, backtrack and pay out this difference with the buses company. So, the mayor of São Paulo, Fernando Haddad, proposed a policy of decentralization of a tax imposed on gasoline, CIDE, to finance urban public transport. In this context, a report was commissioned to Fundação Getúlio Vargas to respond the magnitude of the impact of cross-subsidy between users of private and collective transport. This work uses the results found in this report to answer the effect on traffic in the Metropolitan Region of São Paulo using data from the Source and Destination Survey of 2007. Results show that the cross-subsidy policy provides a low offset in the flow modes of transport. Moreover, the analysis of welfare policy shows that the most favored are the low-income individuals. The estimation is based on two discrete choice models (Multinomial and Mixed Logit), separate for two reasons of trips: work and study. And the simulations of displacement demand use two values of taxes, 0.10 and 0.50 BRL.
103

Trabalho domiciliar feminino no Brasil: determinantes familiares e produtivos do trabalho remunerado exercido no próprio domicílio / Home-based work in Brazil: household and productive determinants for remunerated work at home

Martinez, Thiago Sevilhano 08 April 2008 (has links)
Esta pesquisa investiga os determinantes e a evolução recente no Brasil do trabalho remunerado feminino exercido no próprio domicílio ou simplesmente trabalho domiciliar. Quase 10% da população feminina ocupada, aproximadamente 4,5 milhões de mulheres, tem esse tipo de ocupação. Constatando a inexistência de estudos sobre o tema com dados quantitativos abrangentes, a presente pesquisa utiliza informações da Pesquisa Nacional por Amostras Domiciliares (PNAD) de 1992 a 2005 para analisar como evoluiu a proporção de trabalhadoras domiciliares no total da população ocupada. As mais importantes hipóteses delineadas na literatura a partir de estudos de caso são discutidas pela confrontação com os dados. Sob a ótica da demanda por essa forma de trabalho, analisa-se os setores que mais fazem uso do trabalho domiciliar feminino e as mudanças nessa composição, bem como sua relação com as transformações no mundo do trabalho decorrentes da reestruturação empresarial. Quanto à oferta por trabalho domiciliar, investiga-se como atributos individuais e familiares afetam as chances da mulher estar nesse tipo de condição de ocupação. É debatido como as transformações na inserção produtiva feminina afetaram a importância relativa do trabalho domiciliar. Constrói-se um modelo Logit Multinomial no Stata a partir dos dados da PNAD para comparar como mudou no tempo o impacto de cada atributo sobre a probabilidade de que uma mulher seja trabalhadora domiciliar. / This research investigates the determinants and recent developments of female home-based work in Brazil. Almost 10% of the occupied female population, approximately 4.5 million women, has this kind of occupation. Noting the lack of studies on the topic with comprehensive quantitative data, the present research uses information from PNAD beginning on 1992 until 2005 to evaluate how the proportion of female home-based workers on occupied population evolved. The most important assumptions outlined in the literature from case studies are discussed by confrontation with the data. From the perspective of demand for this type of work, sectors that intensively use female home-based work are analyzed, as well as its relationship with the changes in the labor market resulting from firms restructuring. On the supply of home-based work, it is investigated how individual and family attributes affect the chances of a woman to be in this work condition. It is discussed how the changes on female\'s productive insertion affected the relative importance of home-based work. A Multinomial Logit model is built on Stata using the data from PNAD to compare how the impacts of each attribute on the probability of a woman being home-based worker changed over time.
104

Modeling value of travel time to competitors by different ways logit models: what you win and lose that? / Modelando valor de tempo de viagem para modos concorrentes por diferentes modelos logit: o que se ganha e o que se perde?

Francisco Gildemir Ferreira da Silva 13 September 2011 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Economists since 1965 search a way to measure the value of time. This paper addresses empirical results from a theoretical background proposed in the particular case of transport. The Tuong and Hensher (1985) paper unified the theory and empirical measurement however, over the years various methods for estimation of discrete choice models were not used to measure the values of travel time. This thesis measures the value of travel time of the intercity transport users in Cearà using four models: unstructured type McFadden and the other three, as proposed in Tuong and Hensher (1985a) (Becker, and DeSerpa and Tuong Hensher via Taylor expansion). Additional to the traditional logit model, it estimates the same models using the methodology developed by Morikawa (1989) and simulated maximum likelihood estimation and Bayesian to logit models like in Train (2003). The result indicates that it should use the estimation methods and different functional forms sparingly, because depending on the parameters obtained can be found values for travel time considerably different. On the other hand, the functional forms can be good for prediction. A choice of estimation methods such as enrichment suggests less distortion from standard model. A choice of functional form indicates the use the model of Becker or DeSerpa because of their small oscillation regardless of the estimation methods used. Already a combined choice of estimation method and functional form suggests Becker or DeSerpa with Simulated Maximum Likelihood estimation to obtain values of travel time and to forecasts. / Economistas desde 1965 debruÃam-se sobre uma forma de como mensurar o valor do tempo. O trabalho de Tuong e Hensher (1985) uniu teoria ao empirismo, entretanto, com o passar dos anos os mÃtodos diversos de estimaÃÃo por modelos de escolha discreta nÃo foram utilizados para a mediÃÃo do valor de tempo de viagem. Esta tese mensura o valor de tempo de viagem dos usuÃrios de transporte intermunicipal no Cearà utilizando de quatro modelos: nÃo estruturado tipo McFadden e os outros trÃs, conforme proposto em Tuong e Hensher (1985a), para Becker, DeSerpa e a proposta de Tuong e Hensher via expansÃo de Taylor. Adicional ao modelo logit tradicional, faz-se estimaÃÃes das mesmas formas funcionais utilizando da metodologia desenvolvida por Morikawa (1989) e depois a de estimaÃÃes de mÃxima verossimilhanÃa simulada e bayesiana para modelo logit com fatores aleatÃrios apresentada em Train (2003). O resultado indica que se devem utilizar os mÃtodos de estimaÃÃo e formas funcionais distintas com parcimÃnia, pois dependendo dos parÃmetros obtidos, podem ser encontrados valores para tempo de viagem consideravelmente diferente. Por outro lado, as formas funcionais podem ser boas para previsÃo tal como discutido acima. Uma escolha entre mÃtodos de estimaÃÃo sugere o enriquecimento como o que menos distorce as estimativas do logit padrÃo. Uma escolha de forma funcional indica o uso do modelo de Becker ou do DeSerpa por conta da sua pequena oscilaÃÃo independentemente dos mÃtodos de estimaÃÃo utilizados. Jà uma escolha combinada entre mÃtodo de estimaÃÃo e forma funcional sugere o modelo de Becker e DeSerpa com MÃxima VerossimilhanÃa Simulada, tanto para obter valores de tempo de viagem como para prever eventos.
105

Determinantes de la brecha de género en la inclusión financiera del Perú durante el 2016 / Determinants of the gender gap in the financial inclusion of Peru during 2016

Ortiz Huerta, Gonzalo 02 July 2019 (has links)
La presente investigación tiene como objetivo central identificar cuáles son los principales determinantes que influyen en la brecha de género en la inclusión financiera del Perú durante 2016. En tal sentido, se utiliza la Encuesta Nacional de Demanda de Servicios Financieros y Nivel de Cultura Financiera (ENIF, 2016), en la cual se encuestó a 6,303 individuos seleccionados al azar, formando una muestra representativa de todo el Perú, y se realiza la estimación de modelos de elección discreta (logit y probit). Además, se calculan los impactos marginales de las variables socioeconómicas sobre la posesión de cuentas de ahorro y tarjetas de crédito tanto para varones como mujeres. Los resultados muestran que el nivel educativo es la variable que genera un mayor aumento en la probabilidad de acceder al sistema financiero aunque no de manera muy diferenciada entre géneros; mientras que la posesión de activos, relación de parentesco, residencia y estado civil generan impactos menores en el género femenino. / The main objective of this research is to identify the main determinants that influence the gender gap in the financial inclusion of Peru during 2016. In this sense, the National Survey of Demand for Financial Services and Level of Financial Culture (ENIF, 2016) is used, in which 6,303 randomly selected individuals were surveyed, forming a representative sample of Peru. The estimation of discrete choice models (logit and probit) is made. In addition, the marginal impacts of socioeconomic variables on the possession of savings accounts and credit cards for both men and women are calculated. The results show that the educational level is the variable that generates a greater increase in the probability of accessing the financial system although not in a very differentiated way between genders; while the possession of assets, kinship relationship, residence and marital status generate minor impacts on the female gender. / Trabajo de investigación
106

Dynamic Demand for New and Used Durable Goods without Physical Depreciation

Ishihara, Masakazu 31 August 2011 (has links)
This thesis studies the interaction between new and used durable goods without physical depreciation. In product categories such as CDs/DVDs and video games, the competition from used goods markets has been viewed as a serious problem by producers. These products physically depreciate negligibly, but owners' consumption values could depreciate quickly due to satiation. Consequently, used goods that are almost identical to new goods may become available immediately after a new product release. However, the existence of used goods markets also provides consumers with a selling opportunity. If consumers are forward-looking and account for the future resale value of a product in their buying decision, used goods markets could increase the sales of new goods. Thus, whether used good markets are harmful or beneficial to new-good producers is an empirical question. To tackle this question, I extend the previous literature in three ways. First, I assemble a new data set from the Japanese video game market. This unique data set includes not only the sales and prices of new and used goods, but also the resale value of used copies, the quantity of used copies retailers purchased from consumers, and the inventory level of used copies at retailers. Second, I develop a structural model of forward-looking consumers that incorporates (i) new and used goods buying decisions, (ii) used goods selling decisions, (iii) consumer expectations about future prices of new and used goods as well as resale values of used goods, and (iv) the depreciation of both owners' and potential buyers' consumption values. Third, I develop a new Bayesian estimation method to estimate my model. In particular, my method can alleviate the computational burden of estimating non-stationary discrete choice dynamic programming models with continuous state variables that evolve stochastically over time. The estimation results suggest that consumers are forward-looking in the Japanese video game market and the substitutability between new and used video games is quite low. Using the estimates, I quantify the impact of eliminating the used video game market on new-game revenues. I find that the elimination of used video game market could reduce the revenue for a new game.
107

Dynamic Demand for New and Used Durable Goods without Physical Depreciation

Ishihara, Masakazu 31 August 2011 (has links)
This thesis studies the interaction between new and used durable goods without physical depreciation. In product categories such as CDs/DVDs and video games, the competition from used goods markets has been viewed as a serious problem by producers. These products physically depreciate negligibly, but owners' consumption values could depreciate quickly due to satiation. Consequently, used goods that are almost identical to new goods may become available immediately after a new product release. However, the existence of used goods markets also provides consumers with a selling opportunity. If consumers are forward-looking and account for the future resale value of a product in their buying decision, used goods markets could increase the sales of new goods. Thus, whether used good markets are harmful or beneficial to new-good producers is an empirical question. To tackle this question, I extend the previous literature in three ways. First, I assemble a new data set from the Japanese video game market. This unique data set includes not only the sales and prices of new and used goods, but also the resale value of used copies, the quantity of used copies retailers purchased from consumers, and the inventory level of used copies at retailers. Second, I develop a structural model of forward-looking consumers that incorporates (i) new and used goods buying decisions, (ii) used goods selling decisions, (iii) consumer expectations about future prices of new and used goods as well as resale values of used goods, and (iv) the depreciation of both owners' and potential buyers' consumption values. Third, I develop a new Bayesian estimation method to estimate my model. In particular, my method can alleviate the computational burden of estimating non-stationary discrete choice dynamic programming models with continuous state variables that evolve stochastically over time. The estimation results suggest that consumers are forward-looking in the Japanese video game market and the substitutability between new and used video games is quite low. Using the estimates, I quantify the impact of eliminating the used video game market on new-game revenues. I find that the elimination of used video game market could reduce the revenue for a new game.
108

La imagen de empresa como factor determinante en la elección de operador: identidad y posicionamiento de las empresas de comunicaciones móviles

García de los Salmones Sánchez, María del Mar 12 April 2002 (has links)
La imagen corporativa se constituye como un activo intangible fuente de ventajas competitivas que debe ser correctamente gestionado para extraerle todo su potencial. Partiendo de una revisión de literatura sobre imagen e identidad, la Tesis profundiza en el carácter multidimensional de la imagen y en las variables que influyen en la misma. Para ello se plantean diversas hipótesis referidas a los determinantes de la elección de empresa con mejor imagen global, desarrollando al respecto un modelo de elección discreta cuyos datos se toman de una investigación de mercados centrada en el mercado de la telefonía móvil. Como resultado, se obtiene el importante peso de la dimensión comercial a la hora de valorar a una compañía como la de mejor valoración global, así como del conocimiento y la familiaridad. Por otra parte, la comunicación publicitaria e interpersonal tiene un efecto más significativo en el caso de las empresas menos notorias.
109

Essays on econometric modeling of subjective perceptions of risks in environment and human health

Nguyen, To Ngoc 15 May 2009 (has links)
A large body of literature studies the issues of the option price and other ex-ante welfare measures under the microeconomic theory to valuate reductions of risks inherent in environment and human health. However, it does not offer a careful discussion of how to estimate risk reduction values using data, especially the modeling and estimating individual perceptions of risks present in the econometric models. The central theme of my dissertation is the approaches taken for the empirical estimation of probabilistic risks under alternative assumptions about individual perceptions of risk involved: the objective probability, the Savage subjective probability, and the subjective distributions of probability. Each of these three types of risk specifications is covered in one of the three essays. The first essay addresses the problem of empirical estimation of individual willingness to pay for recreation access to public land under uncertainty. In this essay I developed an econometric model and applied it to the case of lottery-rationed hunting permits. The empirical result finds that the model correctly predicts the responses of 84% of the respondents in the Maine moose hunting survey. The second essay addresses the estimation of a logit model for individual binary choices that involve heterogeneity in subjective probabilities. For this problem, I introduce the use of the hierarchical Bayes to estimate, among others, the parameters of distribution of subjective probabilities. The Monte Carlo study finds the estimator asymptotically unbiased and efficient. The third essay addresses the problem of modeling perceived mortality risks from arsenic concentrations in drinking water. I estimated a formal model that allows for ambiguity about risk. The empirical findings revealed that perceived risk was positively associated with exposure levels and also related individuating factors, in particular smoking habits and one’s current health status. Further evidence was found that the variance of the perceived risk distribution is non-zero. In all, the three essays contribute methodological approaches and provide empirical examples for developing empirical models and estimating value of risk reductions in environment and human health, given the assumption about the individual’s perceptions of risk, and accordingly, the reasonable specifications of risks involved in the models.
110

Development of models for understanding causal relationships among activity and travel variables

Ye, Xin 01 June 2006 (has links)
Understanding joint and causal relationships among multiple endogenous variables has been of much interest to researchers in the field of activity and travel behavior modeling. Structural equation models have been widely developed for modeling and analyzing the causal relationships among travel time, activity duration, car ownership, trip frequency and activity frequency. In the model, travel time and activity duration are treated as continuous variables, while car ownership, trip frequency and activity frequency as ordered discrete variables. However, many endogenous variables of interest in travel behavior are not continuous or ordered discrete but unordered discrete in nature, such as mode choice, destination choice, trip chaining pattern and time-of-day choice (it can be classified into a few categories such as AM peak, midday, PM peak and off-peak). A modeling methodology with involvement of unordered discrete variables is highly desired for better understanding the causal relationships among these variables. Under this background, the proposed dissertation study will be dedicated into seeking an appropriate modeling methodology which aids in identifying the causal relationships among activity and travel variables including unordered discrete variables. In this dissertation, the proposed modeling methodologies are applied for modeling the causal relationship between three pairs of endogenous variables: trip chaining pattern vs. mode choice, activity timing vs. duration and trip departure time vs.mode choice. The data used for modeling analysis is extracted from Swiss Travel Microcensus 2000. Such models provide us with rigorous criteria in selecting a reasonable application sequence of sub-models in the activity-based travel demand model system.

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