923 resultados para Quantile regressions


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Nested by linear cointegration first provided in Granger (1981), the definition of nonlinear cointegration is presented in this paper. Sequentially, a nonlinear cointegrated economic system is introduced. What we mainly study is testing no nonlinear cointegration against nonlinear cointegration by residual-based test, which is ready for detecting stochastic trend in nonlinear autoregression models. We construct cointegrating regression along with smooth transition components from smooth transition autoregression model. Some properties are analyzed and discussed during the estimation procedure for cointegrating regression, including description of transition variable. Autoregression of order one is considered as the model of estimated residuals for residual-based test, from which the teststatistic is obtained. Critical values and asymptotic distribution of the test statistic that we request for different cointegrating regressions with different sample sizes are derived based on Monte Carlo simulation. The proposed theoretical methods and models are illustrated by an empirical example, comparing the results with linear cointegration application in Hamilton (1994). It is concluded that there exists nonlinear cointegration in our system in the final results.

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This is a note about proxy variables and instruments for identification of structural parameters in regression models. We have experienced that in the econometric textbooks these two issues are treated separately, although in practice these two concepts are very often combined. Usually, proxy variables are inserted in instrument variable regressions with the motivation they are exogenous. Implicitly meaning they are exogenous in a reduced form model and not in a structural model. Actually if these variables are exogenous they should be redundant in the structural model, e.g. IQ as a proxy for ability. Valid proxies reduce unexplained variation and increases the efficiency of the estimator of the structural parameter of interest. This is especially important in situations when the instrument is weak. With a simple example we demonstrate what is required of a proxy and an instrument when they are combined. It turns out that when a researcher has a valid instrument the requirements on the proxy variable is weaker than if no such instrument exists

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This paper generalizes the HEGY-type test to detect seasonal unit roots in data at any frequency, based on the seasonal unit root tests in univariate time series by Hylleberg, Engle, Granger and Yoo (1990). We introduce the seasonal unit roots at first, and then derive the mechanism of the HEGY-type test for data with any frequency. Thereafter we provide the asymptotic distributions of our test statistics when different test regressions are employed. We find that the F-statistics for testing conjugation unit roots have the same asymptotic distributions. Then we compute the finite-sample and asymptotic critical values for daily and hourly data by a Monte Carlo method. The power and size properties of our test for hourly data is investigated, and we find that including lag augmentations in auxiliary regression without lag elimination have the smallest size distortion and tests with seasonal dummies included in auxiliary regression have more power than the tests without seasonal dummies. At last we apply the our test to hourly wind power production data in Sweden and shows there are no seasonal unit roots in the series.

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This thesis consists of a summary and five self-contained papers addressing dynamics of firms in the Swedish wholesale trade sector. Paper [1] focuses upon determinants of new firm formation in the Swedish wholesale trade sector, using two definitions of firms’ relevant markets, markets defined as administrative areas, and markets based on a cost minimizing behavior of retailers. The paper shows that new entering firms tend to avoid regions with already high concentration of other firms in the same branch of wholesaling, while right-of-the-center local government and quality of the infrastructure have positive impacts upon entry of new firms. The signs of the estimated coefficients remain the same regardless which definition of relevant market is used, while the size of the coefficients is generally higher once relevant markets delineated on the cost-minimizing assumption of retailers are used. Paper [2] analyses determinant of firm relocation, distinguishing between the role of the factors in in-migration municipalities and out-migration municipalities. The results of the analysis indicate that firm-specific factors, such as profits, age and size of the firm are negatively related to the firm’s decision to relocate. Furthermore, firms seems to be avoiding municipalities with already high concentration of firms operating in the same industrial branch of wholesaling and also to be more reluctant to leave municipalities governed by right-of-the- center parties. Lastly, firms seem to avoid moving to municipalities characterized with high population density. Paper [3] addresses determinants of firm growth, adopting OLS and a quantile regression technique. The results of this paper indicate that very little of the firm growth can be explained by the firm-, industry- and region-specific factors, controlled for in the estimated models. Instead, the firm growth seems to be driven by internal characteristics of firms, factors difficult to capture in conventional statistics. This result supports Penrose’s (1959) suggestion that internal resources such as firm culture, brand loyalty, entrepreneurial skills, and so on, are important determinants of firm growth rates. Paper [4] formulates a forecasting model for firm entry into local markets and tests this model using data from the Swedish wholesale industry. The empirical analysis is based on directly estimating the profit function of wholesale firms and identification of low- and high-return local markets. The results indicate that 19 of 30 estimated models have more net entry in high-return municipalities, but the estimated parameters is only statistically significant at conventional level in one of our estimated models, and then with unexpected negative sign. Paper [5] studies effects of firm relocation on firm profits of relocating firms, employing a difference-in-difference propensity score matching. Using propensity score matching, the pre-relocalization differences between relocating and non-relocating firms are balanced, while the difference-in-difference estimator controls for all time-invariant unobserved heterogeneity among firms. The results suggest that firms that relocate increase their profits significantly, in comparison to what the profits would be had the firms not relocated. This effect is estimated to vary between 3 to 11 percentage points, depending on the length of the analyzed period. 

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This paper examines the impact of socioeconomic factors on eighth grade achievement test scores in the face of federal and state initiatives for educational reform in Maine. We use student-level data over a five year period to provide a framework for understanding the policy implications of these initiatives. We model performance on standardized tests using a seemingly unrelated regressions approach and then determine the likelihood of meeting the standards defined by the adequate yearly progress requirements of the No Child Left Behind Act and Maine Learning Results initiatives. Our results indicate that the key factors influencing a student’s test scores include the education of a student’s parents, special services received for learning disabilities, and alternative measures of academic achievement.

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Este trabalho avalia a evolução da produtividade industrial brasileira — utilizando um painel de 16 setores da indústria de transformação no período 1985/97 — e o papel da abertura econômica neste processo. Os resultados mostram que a produtividade da indústria brasileira, seja ela medida pelo conceito de produtividade total dos fatores (PTF) ou de produtividade do trabalho, passou por duas fases distintas: de 1985 a 1990, há um processo de estagnação e de 1990 a 1997, a indústria passa a apresentar significativas taxas de crescimento. A abertura comercial, caracterizada por menores tarifas nominais e menores taxas de proteção efetiva, exerce um efeito positivo sobre o aumento da produtividade. Em todas as regressões do modelo — em que se utilizam técnicas de estimação em painéis — não se pode rejeitar a hipótese de que aumentos nas barreiras comerciais implicam menores taxas de crescimento da produtividade do trabalho e da PTF. Este resultado confirma a evidência internacional de que países mais abertos crescem mais rápido e desestimularia a adoção de políticas de restrição comercial como estratégia de desenvolvimento e de proteção à indústria nacional.

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Our main goal in this paper was to measure how e¢ cient is risk sharing between countries. In order to do so, we have used a international risk sharIn this paper we re-analyze the question of the U.S. public debt sustainability by using a quantile autoregression model. This modeling allows for testing whether the behavior of U.S. public debt is asymmetric or not. Our results provide evidence of a band of sustainability. Outside this band, the U.S. public debt is unsustainable. We also nd scal policy to be adequate in the sense that occasional episodes in which the public debt moves out of the band do not pose a threat to long run sustainability.

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The study aims to assess the empirical adherence of the permanent income theory and the consumption smoothing view in Latin America. Two present value models are considered, one describing household behavior and the other open economy macroeconomics. Following the methodology developed in Campbell and Schiller (1987), Bivariate Vector Autoregressions are estimated for the saving ratio and the real growth rate of income concerning the household behavior model and for the current account and the change in national cash ‡ow regarding the open economy model. The countries in the sample are considered separately in the estimation process (individual system estimation) as well as jointly (joint system estimation). Ordinary Least Squares (OLS) and Seemingly Unrelated Regressions (SURE) estimates of the coe¢cients are generated. Wald Tests are then conducted to verify if the VAR coe¢cient estimates are in conformity with those predicted by the theory. While the empirical results are sensitive to the estimation method and discount factors used, there is only weak evidence in favor of the permanent income theory and consumption smoothing view in the group of countries analyzed.

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Esta dissertação visa investigar a estrutura de custos do setor aéreo doméstico brasileiro. A fim de realizar essa investigação com maior detalhamento, faz-se, respectivamente, nos capítulos 1 e 2, descrições histórica e econômica desse setor. Essa investigação permitirá dar uma resposta a polêmica sobre a quantidade de empresas que esse setor comporta; além disso, fornecerá indicações de políticas públicas, para que se possa fazer uma melhor avaliação de possíveis mudanças no comportamento das empresas aéreas existentes.

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Based on the Heckscher-Ohlin-Vanek model, this paper investigates relative factor abundance in Brazil, as revealed by its international trade. We study two different time periods: one characterized by high trade barriers (1980 to 1985) and the trade liberalization period (1990 to 1995). Two alternative methodologies are used: the estimation of factor intensity regressions on net exports and the direct computation of factor content in net exports. In the factor intensity regression, we incorporate technological changes that might have occurred over time, and those turned out to be significant. Both methods yield the same results: the Brazilian international trade reveals relative abundance in capital, land and unskilled labor, and scarcity in skilled labor, with qualitatively equivalent results for the two time periods studied.

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in this anicle we measure the impact of public sector capital and investment on economic growth. Initially, traditional growth accounting regressions are run for a cross-country data set. A simple endogenous growth model is then constructed in order to take into account the determinants of labor, private capital and public capital. In both cases, public capital is a separate argument of the production function. An additional data-set constructed with quarterly American data was used in the estimations of the growth mode!. The results indicate lhat public capital and public investment play a significant role in determining growth rates and have a significant impact on capital and labor returns. Furthermore, the impact of public investment on productivity growth was found to be positive and always significant for bolh samples. Hence. in a fully optimizing modelo we confmn previous results in the literature that lhe failure of public investment to keep pace with output growlh during the Seventies and Eighties may have played a major role in the slowdown of lhe productivity growth in the period. Anolher main outcome concems the output elasticity wilh respect to public capital. The coefficiem estimates are always positive and significant but magnitudes depend on each of lhe two data set used.

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In this paper we re-analyze the question of the U.S. public debt sustainability by using a quantile autoregression model. This modeling allows for testing whether the behavior of U.S. public debt is asymmetric or not. Our results provide evidence of a band of sustainability. Outside this band, the U.S. public debt is unsustainable. We also find fiscal policy to be adequate in the sense that occasional episodes in which the public debt moves out of the band do not pose a threat to long run sustainability.

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In this paper, we compare four different Value-at-Risk (V aR) methodologies through Monte Carlo experiments. Our results indicate that the method based on quantile regression with ARCH effect dominates other methods that require distributional assumption. In particular, we show that the non-robust methodologies have higher probability to predict V aRs with too many violations. We illustrate our findings with an empirical exercise in which we estimate V aR for returns of S˜ao Paulo stock exchange index, IBOVESPA, during periods of market turmoil. Our results indicate that the robust method based on quantile regression presents the least number of violations.

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O presente trabalho tem por objetivo abordar o tema microcrédito e analisar sua experiência mais bem sucedida no Brasil, o CrediAMIGO, do Banco do Nordeste. Há uma descrição do programa e uma análise quantitativa de sua atuação, que será feita a partir de uma base de dados composta pelas pesquisas Ecinf de 1997 e 2003, utilizando regressões logísticas e o método de diferenças em diferenças. Em termos substantivos concluímos que há experiência de microcrédito na região mais pobre do Brasil, baseada em aval solidário, proporcionando aumento no acesso a crédito superior ao resto do país.

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Nível de renda e estado de saúde são variáveis correlacionadas tanto pelo fato de aumentos da primeira propiciarem maior acesso a bens e serviços que se refletem em melborias no estado de saúde das pessoas, como pelos ganhos de produtividade e de renda propiciadas por melborias da saúde do trabalhador. Esse artigo estuda os impactos da renda na saúde no Brasil, tendo como instrtrnlento para lidar com o problema de simultaneidade, as mudanças observadas em políticas de transferência de renda aos idosos de baixa renda. A estratégia usada foi comparar o estado de saúde de pessoas idosas de baixa renda - sem contar o efeito dos benefícios - antes e depois do incremento exógeno do recebimento de novos programas de transferência de renda. Utilizamos um estimador de diferenças em diferenças baseado em regressões logísticas. Os dados foram extraídos de suplementos especiais de saúde de pesquisas domiciliares do IBGE (PNAD 1998 e 2003). O trabalbo demonstra uma melbora diferenciada do estado de saúde de pessoas idosas de baixa renda