946 resultados para Interactive fixed effects
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Thesis (Ph.D.)--University of Washington, 2016-08
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Thesis (Ph.D.)--University of Washington, 2016-08
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O presente artigo tem por objetivo analisar empiricamente os determinantes do financiamento do investimento nos países das Américas no período de 1972-2008, tendo como base teórica os modelos de hiatos nas versões de Chenery e Bruno (1962); Bacha (1982, 1989 e 1990) e Taylor (1994). Com este intuito, realiza-se uma estimação com o modelo de dados em painel na versão padrão com efeitos fixos. As variáveis explicativas de cada país seguem a abordagem de Amadeo e Giambiagi (1990). São elas: os coeficientes de poupança interna e de importação e as exportações reais. Os resultados das estimações corroboram com a concepção teórica do modelo de hiatos, ou seja, que países em desenvolvimento enfrentam limitações de poupança interna e incapacidade de importar bens intensivos em capital, fatores os quais restringem o nível de investimento dessas economias.
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This dissertation explores three aspects of the economics and policy issues surrounding retail payments (low-value frequent payments): the microeconomic aspect, by measuring costs associated with retail payment instruments; the macroeconomic aspect, by quantifying the impact of the use of electronic rather than paper-based payment instruments on consumption and GDP; and the policy aspect, by identifying barriers that keep countries stuck with outdated payment systems, and recommending policy interventions to move forward with payments modernization. Payment system modernization has become a prominent part of the financial sector reform agenda in many advanced and developing countries. Greater use of electronic payments rather than cash and other paper-based instruments would have important economic and social benefits, including lower costs and thereby increased economic efficiency and higher incomes, while broadening access to the financial system, notably for people with moderate and low incomes. The dissertation starts with a general introduction on retail payments. Chapter 1 develops a theoretical model for measuring payments costs, and applies the model to Guyana—an emerging market in the midst of the transition from paper to electronic payments. Using primary survey data from Guyanese consumers, the results of the analysis indicate that annual costs related to the use of cash by consumers reach 2.5 percent of the country’s GDP. Switching to electronic payment instruments would provide savings amounting to 1 percent of GDP per year. Chapter 2 broadens the analysis to calculate the macroeconomic impacts of a move to electronic payments. Using a unique panel dataset of 76 countries across the 17-year span from 1998 to 2014 and a pooled OLS country fixed effects model, Chapter 2 finds that on average, use of debit and credit cards contribute USD 16.2 billion to annual global consumption, and USD 160 billion to overall annual global GDP. Chapter 3 provides an in-depth assessment of the Albanian payment cards and remittances market and recommends a set of incentives and regulations (both carrots and sticks) that would allow the country to modernize its payment system. Finally, the conclusion summarizes the lessons of the dissertation’s research and brings forward issues to be explored by future research in the retail payments area.
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The present doctoral thesis studies the association between pre-colonial institutions and long-run development in Latin America. The thesis is organised as follows: Chapter 1 places the motivation of the thesis by underlying relevant contributions in the literature on long-run development. I then set out the main objective of the thesis, followed by a brief outline of it. In Chapter 2, I study the effects of pre-colonial institutions on present-day socioeconomic outcomes for Latin America. The main thesis of this chapter is that more advanced pre-colonial institutions relate to better socioeconomic outcomes today - principally, but not only, through their effects on the Amerindian population. I test such hypothesis with a dataset of 324 sub-national administrative units covering all mainland Latin American countries. The extensive range of controls covers factors such as climate, location, natural resources, colonial activities and pre-colonial characteristics - plus country fixed effects. Results strongly support the main thesis. In Chapter 3, I further analyse the association between pre-colonial institutions and present-day economic development in Latin America by using the historical ethnic homelands as my main unit of analysis. The main hypothesis is that ethnic homelands inhabited by more advanced ethnic groups -as measured by their levels of institutional complexity- relate to better economic development today. To track these long-run effects, I construct a new dataset by digitising historiographical maps allowing me to pinpoint the geospatial location of ethnic homelands as of the XVI century. As a result, 375 ethnic homelands are created. I then capture the levels of economic development at the ethnic homeland level by making use of alternative economic measures --satellite light density data. After controlling for country-specific characteristics and applying a large battery of geographical, locational, and historical factors, I found that the effects of pre-colonial institutions relate to a higher light density --as a proxy for economic activity- in ethnic homelands where more advanced ethnic groups lived. In Chapter 4, I explore a mechanism linking the persistence of pre-colonial institutions in Latin America over the long-run: Colonial and post-colonial strategies along with the ethnic political capacity worked in tandem allowing larger Amerindian groups to "support" the new political systems in ways that would benefit their respective ethnic groups as well as the population at large. This mechanism may have allowed the effects of pre-colonial institutions to influence socioeconomic development outcomes up to today. To shed lights on this mechanism, I combine the index of pre-colonial institutions prepared for the second chapter of the present thesis with individual-level survey data on people's attitudes. By controlling for key observable and unobservable country-specific characteristics, the main empirical results show that areas with a history of more advanced pre-colonial institutions increase the probability of individuals supporting present-day political institutions. Finally, in Chapter 5, I summarise the main findings of the thesis, and emphasise the key weaknesses of the study as well as potential avenues for future research.
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A produção e qualidade do leite são influenciadas por factores ambientais como a nutrição, factores genéticos como a raça, e factores fisiológicos como a idade a idade ao parto ou o número de ordenhas diárias. Este trabalho teve por objectivo estimar factores de correcção para os efeitos ambientais que influenciam a quantidade e qualidade do leite com vista ao melhoramento genético dos animais. Para isso, foram utilizados os registos de 23897 contrastes leiteiros de vacas de raça Frísia, no período de 6 anos, recolhidos a partir dos dados da ANABLE. De acordo com os resultados, obtidos através do método dos quadrados mínimos, observa-se que para a produção de leite, gordura e proteína, todos os efeitos fixos de variação são significativos nas três características produtivas estudadas, pelo que se conclui que há interacção entre a idade da vaca ao parto e a produção e qualidade do leite, assim como, a época do ano em que ocorre o parto e o número de ordenhas diárias a que o animal está sujeito. ABSTRACT; Cow production and milk quality are influenced by environmental factors such as nutrition, by genetic factors as breed and physiological factors as age at calving or milking frequency. This study aimed to estimate correction parameters for environmental factors with influence on milk production and quality embodying genetic improvement. For this propose, a data base was used with information related to 23987 milk tests collected from official milk recording program. According to the results, where the at least square procedure was adopted, it shows that all the fixed effects of variation significantly affect the productive performances, so it can be concluded that there is a significant interaction between milking frequency, age at calving and season when it occurs, and milk production and quality.
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When a company desires to invest in a project, it must obtain resources needed to make the investment. The alternatives are using firm s internal resources or obtain external resources through contracts of debt and issuance of shares. Decisions involving the composition of internal resources, debt and shares in the total resources used to finance the activities of a company related to the choice of its capital structure. Although there are studies in the area of finance on the debt determinants of firms, the issue of capital structure is still controversial. This work sought to identify the predominant factors that determine the capital structure of Brazilian share capital, non-financial firms. This work was used a quantitative approach, with application of the statistical technique of multiple linear regression on data in panel. Estimates were made by the method of ordinary least squares with model of fixed effects. About 116 companies were selected to participate in this research. The period considered is from 2003 to 2007. The variables and hypotheses tested in this study were built based on theories of capital structure and in empirical researches. Results indicate that the variables, such as risk, size, and composition of assets and firms growth influence their indebtedness. The profitability variable was not relevant to the composition of indebtedness of the companies analyzed. However, analyzing only the long-term debt, comes to the conclusion that the relevant variables are the size of firms and, especially, the composition of its assets (tangibility).This sense, the smaller the size of the undertaking or the greater the representation of fixed assets in total assets, the greater its propensity to long-term debt. Furthermore, this research could not identify a predominant theory to explain the capital structure of Brazilian
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This research work aims to discuss the gender issue concerning entrepreneurship in European Union countries in a period of nine years, from 2007 to 2015, identifying the factors which drive individuals to be entrepreneurs. The study mainly concentrates on identifying and quantifying the personal, social, political and economic features which are motivating individuals, especially women, to be entrepreneurs, as well as the main difficulties they feel during the process of business creation. In order to explore the entrepreneurial activity across a set of developed countries the econometric methodology of panel data (in particular the fixed effects and random effects models) is applied to a data set of entrepreneurial statistical indicators calculated and made available by the Global Entrepreneurship Monitor. The results show that the knowledge of other start-up entrepreneurs, a desired career choice, the governmental support and the existence of public policies that promote entrepreneurship (specially within the framework of small and medium sized firms) and the transfer of R&D are factors influencing negatively on the rate of female entrepreneurship. None of the observed variables are barriers for male entrepreneurs. The perceived capabilities and opportunities, the entrepreneurial intention, the policies to lower taxes and bureaucracy and the social and cultural norms are identified drives for women for engaging in a process of running their own ventures. These findings offer a set of valid knowledge to understand which measures could be implemented or should be changed and improved at a political and managerial level for stimulating entrepreneurship, especially for women.
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Rational choice models argue that income inequality leads to a higher expected utility of crime and thus generates incentives to engage in illegal activities. Yet, the results of empirical studies do not provide strong support for this theory; in fact, Neumayer provides apparently strong evidence that income inequality is not a significant determinant of violent property crime rates when a representative sample is used and country specific fixed effects are controlled for. An important limitation of this and other empirical studies on the subject is that they only consider proportional income differences, even though in rational choice models absolute difference in legal and illegal incomes determine the expected utility of crime. Using the same methodology and data as Neumayer, but using absolute inequality measures rather than proportional ones, this paper finds that absolute income inequality is a statistically significant determinant of robbery and violent theft rates. This result is robust to changes in sample size and to different absolute inequality measures, which not only implies that inequality is an important correlate of violent property crime rates but also suggests that absolute measures are preferable when the impact of inequality on property crime is studied.
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Dissertação (mestrado)—UnB/UFPB/UFRN, Programa MultiInstitucional e Inter-Regional de Pós-Graduação em Ciências Contábeis, 2016.
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Agroforestry has large potential for carbon (C) sequestration while providing many economical, social, and ecological benefits via its diversified products. Airborne lidar is considered as the most accurate technology for mapping aboveground biomass (AGB) over landscape levels. However, little research in the past has been done to study AGB of agroforestry systems using airborne lidar data. Focusing on an agroforestry system in the Brazilian Amazon, this study first predicted plot-level AGB using fixed-effects regression models that assumed the regression coefficients to be constants. The model prediction errors were then analyzed from the perspectives of tree DBH (diameter at breast height)?height relationships and plot-level wood density, which suggested the need for stratifying agroforestry fields to improve plot-level AGB modeling. We separated teak plantations from other agroforestry types and predicted AGB using mixed-effects models that can incorporate the variation of AGB-height relationship across agroforestry types. We found that, at the plot scale, mixed-effects models led to better model prediction performance (based on leave-one-out cross-validation) than the fixed-effects models, with the coefficient of determination (R2) increasing from 0.38 to 0.64. At the landscape level, the difference between AGB densities from the two types of models was ~10% on average and up to ~30% at the pixel level. This study suggested the importance of stratification based on tree AGB allometry and the utility of mixed-effects models in modeling and mapping AGB of agroforestry systems.
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Dissertação de Mestrado, Finanças Empresariais, Faculdade de Economia, Universidade do Algarve, 2016
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Objective: To compare efficacy and safety of primaquine regimens currently used to prevent relapses by Plasmodium vivax. Methods: A systematic review was carried out to identify clinical trials evaluating efficacy and safety to prevent malaria recurrences by P. vivax of primaquine regimen 0.5 mg/kg/day for 7 or 14 days compared to standard regimen of 0.25 mg/kg/day for 14 days. Efficacy of primaquine according to cumulative incidence of recurrences after 28 days was determined. The overall relative risk with fixed-effects meta-analysis was estimated. Results: For the regimen 0.5 mg/kg/day/7 days were identified 7 studies, which showed an incidence of recurrence between 0% and 20% with follow-up 60-210 days; only 4 studies comparing with the standard regimen 0.25 mg/kg/day/14 days and no difference in recurrences between both regimens (RR= 0.977, 95% CI= 0.670 to 1.423) were found. 3 clinical trials using regimen 0.5 mg/kg/day/14 days with an incidence of recurrences between 1.8% and 18.0% during 330-365 days were identified; only one study comparing with the standard regimen (RR= 0.846, 95% CI= 0.484 to 1.477). High risk of bias and differences in handling of included studies were found. Conclusion: Available evidence is insufficient to determine whether currently PQ regimens used as alternative rather than standard treatment have better efficacy and safety in preventing relapse of P. vivax. Clinical trials are required to guide changes in treatment regimen of malaria vivax.
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Objective: To compare efficacy and safety of primaquine regimens currently used to prevent relapses by Plasmodium vivax. Methods: A systematic review was carried out to identify clinical trials evaluating efficacy and safety to prevent malaria recurrences by P. vivax of primaquine regimen 0.5 mg/kg/day for 7 or 14 days compared to standard regimen of 0.25 mg/kg/day for 14 days. Efficacy of primaquine according to cumulative incidence of recurrences after 28 days was determined. The overall relative risk with fixed-effects meta-analysis was estimated. Results: For the regimen 0.5 mg/kg/day/7 days were identified 7 studies, which showed an incidence of recurrence between 0% and 20% with follow-up 60-210 days; only 4 studies comparing with the standard regimen 0.25 mg/kg/day/14 days and no difference in recurrences between both regimens (RR= 0.977, 95% CI= 0.670 to 1.423) were found. 3 clinical trials using regimen 0.5 mg/kg/day/14 days with an incidence of recurrences between 1.8% and 18.0% during 330-365 days were identified; only one study comparing with the standard regimen (RR= 0.846, 95% CI= 0.484 to 1.477). High risk of bias and differences in handling of included studies were found. Conclusion: Available evidence is insufficient to determine whether currently PQ regimens used as alternative rather than standard treatment have better efficacy and safety in preventing relapse of P. vivax. Clinical trials are required to guide changes in treatment regimen of malaria vivax.
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Resumo: Registros de sobrevivência do nascimento ao desmame de 3846 crias de ovinos da raça Santa Inês foram analisados por modelos de reprodutor linear e não linear (modelo de limiar), para estimar componentes de variância e herdabilidade. Os modelos usados para sobrevivência, analisada como característica da cria, incluíram os efeitos fixos de sexo, da combinação tipo de nascimento-criação da cria e da idade da ovelha ao parto, efeito da covariável peso da cria ao nascer e efeitos aleatórios de reprodutor, da classe rebanho-ano-estação e do resíduo. Componentes de variância para o modelo linear foram estimados pelo método da máxima verossimilhança restrita (REML) e para o modelo não linear por uma aproximação da máxima verossimilhança marginal (MML), pelo programa CMMAT2. O coeficiente de herdabilidade (h2) estimado pelo modelo de limiar foi de 0,29, e pelo modelo linear, 0,14. A correlação de ordem de Spearman entre as capacidades de transmissão dos reprodutores, com base nos dois modelos foi de 0,96. As estimativas de h2 obtidas indicam a possibilidade de se obter, por seleção, ganho genético para sobrevivência. [Linear and nonlinear models in genetic analyses of lamb survival in the Santa Inês hair sheep breed]. Abstract: Records of 3,846 lambs survival from birth to weaning of Santa Inês hair sheep breed, were analyzed by linear and non linear sire models (threshold model) to estimate variance components and heritability (h2). The models that were used to analyze survival, considered in this study as a lamb trait, included the fixed effects of sex of the lamb, combination of type of birth-rearing of lamb, and age of ewe, birth weight of lamb as covariate, and random effects of sire, herd-year-season and residual. Variance components were obtained using restricted maximum likelihood (REML), in linear model and marginal maximum likelihood in threshold model through CMMAT2 program. Estimate of heritability (h2) obtained by threshold model was 0.29 and by linear model was 0.14. Rank correlation of Spearman, between sire solutions based on the two models was 0.96. The obtained estimates in this study indicate that it is possible to acquire genetic gain to survival by selection.