30 resultados para semi-empirical shell model
em Repositório digital da Fundação Getúlio Vargas - FGV
Resumo:
In this paper, we propose a class of ACD-type models that accommodates overdispersion, intermittent dynamics, multiple regimes, and sign and size asymmetries in financial durations. In particular, our functional coefficient autoregressive conditional duration (FC-ACD) model relies on a smooth-transition autoregressive specification. The motivation lies on the fact that the latter yields a universal approximation if one lets the number of regimes grows without bound. After establishing that the sufficient conditions for strict stationarity do not exclude explosive regimes, we address model identifiability as well as the existence, consistency, and asymptotic normality of the quasi-maximum likelihood (QML) estimator for the FC-ACD model with a fixed number of regimes. In addition, we also discuss how to consistently estimate using a sieve approach a semiparametric variant of the FC-ACD model that takes the number of regimes to infinity. An empirical illustration indicates that our functional coefficient model is flexible enough to model IBM price durations.
Resumo:
We study the effects of population size in the Peck-Shell analysis of bank runs. We find that a contract featuring equal-treatment for almost all depositors of the same type approximates the optimum. Because the approximation also satisfies Green-Lin incentive constraints, when the planner discloses positions in the queue, welfare in these alternative specifications are sandwiched. Disclosure, however, it is not needed since our approximating contract is not subject to runs.
Resumo:
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.
Resumo:
After more than forty years studying growth, there are two classes of growth models that have emerged: exogenous and endogenous growth models. Since both try to mimic the same set of long-run stylized facts, they are observationally equivalent in some respects. Our goals in this paper are twofold First, we discuss the time-series properties of growth models in a way that is useful for assessing their fit to the data. Second, we investigate whether these two models successfully conforms to U.S. post-war data. We use cointegration techniques to estimate and test long-run capital elasticities, exogeneity tests to investigate the exogeneity status of TFP, and Granger-causality tests to examine temporal precedence of TFP with respect to infrastructure expenditures. The empirical evidence is robust in confirming the existence of a unity long-run capital elasticity. The analysis of TFP reveals that it is not weakly exogenous in the exogenous growth model Granger-causality test results show unequivocally that there is no evidence that TFP for both models precede infrastructure expenditures not being preceded by it. On the contrary, we find some evidence that infras- tructure investment precedes TFP. Our estimated impact of infrastructure on TFP lay rougbly in the interval (0.19, 0.27).
Resumo:
Parametric term structure models have been successfully applied to innumerous problems in fixed income markets, including pricing, hedging, managing risk, as well as studying monetary policy implications. On their turn, dynamic term structure models, equipped with stronger economic structure, have been mainly adopted to price derivatives and explain empirical stylized facts. In this paper, we combine flavors of those two classes of models to test if no-arbitrage affects forecasting. We construct cross section (allowing arbitrages) and arbitrage-free versions of a parametric polynomial model to analyze how well they predict out-of-sample interest rates. Based on U.S. Treasury yield data, we find that no-arbitrage restrictions significantly improve forecasts. Arbitrage-free versions achieve overall smaller biases and Root Mean Square Errors for most maturities and forecasting horizons. Furthermore, a decomposition of forecasts into forward-rates and holding return premia indicates that the superior performance of no-arbitrage versions is due to a better identification of bond risk premium.
Resumo:
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.
Resumo:
The goal of this paper is to show the possibility of a non-monotone relation between coverage ans risk which has been considered in the literature of insurance models since the work of Rothschild and Stiglitz (1976). We present an insurance model where the insured agents have heterogeneity in risk aversion and in lenience (a prevention cost parameter). Risk aversion is described by a continuous parameter which is correlated with lenience and for the sake of simplicity, we assume perfect correlation. In the case of positive correlation, the more risk averse agent has higher cosr of prevention leading to a higher demand for coverage. Equivalently, the single crossing property (SCP) is valid and iplies a positive correlation between overage and risk in equilibrium. On the other hand, if the correlation between risk aversion and lenience is negative, not only may the SCP be broken, but also the monotonocity of contracts, i.e., the prediction that high (low) risk averse types choose full (partial) insurance. In both cases riskiness is monotonic in risk aversion, but in the last case there are some coverage levels associated with two different risks (low and high), which implies that the ex-ante (with respect to the risk aversion distribution) correlation between coverage and riskiness may have every sign (even though the ex-post correlation is always positive). Moreover, using another instrument (a proxy for riskiness), we give a testable implication to desentangle single crossing ans non single croosing under an ex-post zero correlation result: the monotonicity of coverage as a function os riskiness. Since by controlling for risk aversion (no asymmetric information), coverage is monotone function of riskiness, this also fives a test for asymmetric information. Finally, we relate this theoretical results to empirical tests in the recent literature, specially the Dionne, Gouruéroux and Vanasse (2001) work. In particular, they found an empirical evidence that seems to be compatible with asymmetric information and non single crossing in our framework. More generally, we build a hidden information model showing how omitted variables (asymmetric information) can bias the sign of the correlation of equilibrium variables conditioning on all observable variables. We show that this may be the case when the omitted variables have a non-monotonic relation with the observable ones. Moreover, because this non-dimensional does not capture this deature. Hence, our main results is to point out the importance of the SPC in testing predictions of the hidden information models.
Resumo:
We estimate and test two alternative functional forms, which have been used in the growth literature, representing the aggregate production function for a panel of countries: the model of Mankiw, Romer and Weil (Quarterly Journal of Economics, 1992), and a mincerian formulation of schooling-returns to skills. Estimation is performed using instrumental-variable techniques, and both functional forms are confronted using a Box-Cox test, since human capital inputs enter in levels in the mincerian specification and in logs in the extended neoclassical growth model.
Resumo:
o objetivo desta pesquisa foi a identificação e a determinação dos principais elementos presentes no desenvolvimento de ações de responsabilidade social e programas de marketing social em unidades industriais de duas empresas, da iniciativa privada, localizadas em Curitiba: Bosch e Inepar. Na base teóricoempírica, foram analisados os aspectos referentes à gestão social sob o paradigma da Sociedade Pós-Industrial, à responsabilidade social e ao marketing social. Especificamente nestes dois últimos temas foi aprofundada a análise de suas bases de formação e a evolução de seus conceitos, bem como suas diferentes interpretações, tratamentos, usos e motivações para a efetivação de programas de cunho social. O método que caracteriza esta pesquisa é o de dois estudos de caso distintos. Os dados foram obtidos mediante pesquisa bibliográfica, análise de documentos internos e peças de comunicação externas, observação direta e por meio de entrevistas semi-estruturadas, realizadas com os dirigentes e funcionários das organizações estudadas, envolvidos na condução e organização de práticas sociais. A análise foi efetuada de forma descritivo-qualitativa. Os dados coletados revelaram a existência de consonâncias e dissonâncias entre a prática da responsabilidade social e do marketing social e o discurso apresentado pelas empresas. O objetivo maior do estudo foi ampliar o entendimento acerca da responsabilidade social e do marketing social praticado pela iniciativa privada, tendo como referência a visão de seus integrantes, dentro das atuais racionalidades econômica e social que estabelecem um novo modelo de relacionamento entre Estado, empresas e sociedade civil.
Resumo:
O estudo, fundamentado nas premissas teóricas sobre relações de trabalho, em especial de algumas variáveis que integram a categoria microssocial - organização do trabalho e condições de trabalho - aliadas às contribuições da Escola Dejouriana, que analisa os temas do prazer e do sofrimento vinculados ao trabalho, procura desvendar o processo de desgaste/prazer no trabalho dentro de um hospital universitário, trazido através do discurso dos trabalhadores de enfermagem ali atuantes, buscando captar suas realizações, dificuldades, alegrias, tramas e defesas, angústias, contradições, a luta pelo poder, as vivências subjetivas, os silêncios. A presente pesquisa de caráter exploratório, por meio de um roteiro com questões fechadas e entrevistas semi-estruturadas, envolvendo trinta e seis profissionais, representantes das categorias enfermeiro, técnico de enfermagem e auxiliar de enfermagem visou apreender a realidade laboral do Hospital Universitário de Juiz de Fora, tentando delinear os contextos de trabalho vividos como positivo ou negativos, denunciando pontos na convergência trabalhador-contexto de trabalho, a partir dos quais as mudanças devam ser impulsionadas, para que se possa criar novas.estratégias, dirimir conflitos e ampliar as possibilidades de auto-realização e prazer no trabalho. As categorias de análise definidas no estudo possibilitaram uma reflexão sobre os desafios e problemas que surgem da relação trabalhador/trabalho/instituição. O conhecimento dos fatores implicados na gênese do desgaste/prazer no trabalho de enfermagem abre espaço para que estes sejam gerenciados pelos trabalhadores em proveito de sua saúde e qualidade de vida. Em suma, temos que a trajetória da enfermagem de anjo de branco a profissional tem sido marcada por preconceitos, desgaste, sofrimento e luta por espaço laboral. Abandonando a posição de saber periférico e vulnerável, assistimos atualmente o esforço dos trabalhadores de enfermagem para a construção de uma nova imagem que contempla estratégias de revalorização do estatuto profissional, controle da formação, das carreiras e dos conteúdos do trabalho para que se tornem agentes privilegiados e ativos na melhoria das condições de saúde da comunidade e propulsoras de novas idéias para o avanço da gestão nas organizações hospitalares.
Resumo:
We study the joint determination of the lag length, the dimension of the cointegrating space and the rank of the matrix of short-run parameters of a vector autoregressive (VAR) model using model selection criteria. We consider model selection criteria which have data-dependent penalties as well as the traditional ones. We suggest a new two-step model selection procedure which is a hybrid of traditional criteria and criteria with data-dependant penalties and we prove its consistency. Our Monte Carlo simulations measure the improvements in forecasting accuracy that can arise from the joint determination of lag-length and rank using our proposed procedure, relative to an unrestricted VAR or a cointegrated VAR estimated by the commonly used procedure of selecting the lag-length only and then testing for cointegration. Two empirical applications forecasting Brazilian inflation and U.S. macroeconomic aggregates growth rates respectively show the usefulness of the model-selection strategy proposed here. The gains in different measures of forecasting accuracy are substantial, especially for short horizons.
Resumo:
This paper analyses the equilibrium structure of protection in Mercosul, developing empirical analyses based on the literature ensuing from the sequence of models set forth by Grossman and Helpman since 1994. Not only Mercosul’s common external tariff (CET) may be explained under a political economy perspective, but the existence of deviations, both at the level of the external tariffs and at that of the internal ones, make it interesting to contrast several structures under this approach. Different general equilibrium frameworks, in which governments are concerned with campaign contributions and with the welfare of the average voter, while organized special-interest groups care only about the welfare of their members, are used as the theoretical basis of the empirical tests. We build a single equation for explaining the CET and two fourequations systems (one equation for each member) for explaining deviations from the CET and from the internal free trade between members. The results (at the two-digit level) shed an interesting light on the sectoral dynamics of protection in each country; notably, Brazil seems to fit in better in the model framework, followed by Uruguay. In the case of the CET, and of deviations from it, the interaction between the domestic lobbies in the four countries plays a major role. There is also suggestion that the lobby structure that bid for deviations, be they internal or external, differs from the one which bid for the CET.
Resumo:
We estimate and test two alternative functional forms representing the aggregate production function for a panel of countries: the extended neoclassical growth model, and a mincerian formulation of schooling-returns to skills. Estimation is performed using instrumentalvariable techniques, and both functional forms are confronted using a Box-Cox test, since human capital inputs enter in levels in the mincerian specification and in logs in the extended neoclassical growth model. Our evidence rejects the extended neoclassical growth model in favor of the mincerian specification, with an estimated capital share of about 42%, a marginal return to education of about 7.5% per year, and an estimated productivity growth of about 1.4% per year. Differences in productivity cannot be disregarded as an explanation of why output per worker varies so much across countries: a variance decomposition exercise shows that productivity alone explains 54% of the variation in output per worker across countries.
Resumo:
When the joint assumption of optimal risk sharing and coincidence of beliefs is added to the collective model of Browning and Chiappori (1998) income pooling and symmetry of the pseudo-Hicksian matrix are shown to be restored. Because these are also the features of the unitary model usually rejected in empirical studies one may argue that these assumptions are at odds with evidence. We argue that this needs not be the case. The use of cross-section data to generate price and income variation is based Oil a definition of income pooling or symmetry suitable for testing the unitary model, but not the collective model with risk sharing. AIso, by relaxing assumptions on beliefs, we show that symmetry and income pooling is lost. However, with usual assumptions on existence of assignable goods, we show that beliefs are identifiable. More importantly, if di:fferences in beliefs are not too extreme, the risk sharing hypothesis is still testable.
Resumo:
We study the joint determination of the lag length, the dimension of the cointegrating space and the rank of the matrix of short-run parameters of a vector autoregressive (VAR) model using model selection criteria. We consider model selection criteria which have data-dependent penalties as well as the traditional ones. We suggest a new two-step model selection procedure which is a hybrid of traditional criteria and criteria with data-dependant penalties and we prove its consistency. Our Monte Carlo simulations measure the improvements in forecasting accuracy that can arise from the joint determination of lag-length and rank using our proposed procedure, relative to an unrestricted VAR or a cointegrated VAR estimated by the commonly used procedure of selecting the lag-length only and then testing for cointegration. Two empirical applications forecasting Brazilian in ation and U.S. macroeconomic aggregates growth rates respectively show the usefulness of the model-selection strategy proposed here. The gains in di¤erent measures of forecasting accuracy are substantial, especially for short horizons.