925 resultados para Panel cointegration


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Presented at the Society's annual meeting in Hartford, Conn., July 6, 1967, by Andrew A. Melgard, Charles E. Tosch and Frank Cummings.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Includes bibliographical references (p. [69]-[76]).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cover title.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Vol. 2 has imprint: Ann Arbor, Institute for Social Research, University of Michigan.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

"Greg J. Duncan and James N. Morgan are the principal researchers."

Relevância:

20.00% 20.00%

Publicador:

Resumo:

En este trabajo se ofrece evidencia de los efectos positivos de la descentralización fiscal en el crecimiento económico regional en Colombia desde la promulgación de la Constitución Política de 1991. La estrategia empírica incluyó la elección de un estimador adecuado para el enfoque de panel de datos, el estimador “promedio del grupo aumentado” (amg, por sus siglas en inglés), que permitió agregar factores determinantes no observados, sugeridos por la literatura, a los factores explicativos de largo plazo tradicionales. La estrategia se complementó con ejercicios que brindaron apoyo a los resultados de i) modelos de corte transversal para diferentes períodos y diversas variables de control, ii) una prueba de la hipótesis de complementariedad entre los bienes públicos suministrados por diferentes jurisdicciones (efectos indirectos), y iii) una evaluación de la convergencia incondicional en las diferencias de ingreso regionales.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The multibody dynamics of a satellite in circular orbit, modeled as a central body with two hinge-connected deployable solar panel arrays, is investigated. Typically, the solar panel arrays are deployed in orbit using preloaded torsional springs at the hinges in a near symmetrical accordion manner, to minimize the shock loads at the hinges. There are five degrees of freedom of the interconnected rigid bodies, composed of coupled attitude motions (pitch, yaw and roll) of the central body plus relative rotations of the solar panel arrays. The dynamical equations of motion of the satellite system are derived using Kane's equations. These are then used to investigate the dynamic behavior of the system during solar panel deployment via the 7-8th-order Runge-Kutta integration algorithms and results are compared with approximate analytical solutions. Chaotic attitude motions of the completely deployed satellite in circular orbit under the influence of the gravity-gradient torques are subsequently investigated analytically using Melnikov's method and confirmed via numerical integration. The Hamiltonian equations in terms of Deprit's variables are used to facilitate the analysis. (C) 2003 Published by Elsevier Ltd.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Category-management models serve to assist in the development of plans for pricing and promotions of individual brands. Techniques to solve the models can have problems of accuracy and interpretability because they are susceptible to spurious regression problems due to nonstationary time-series data. Improperly stated nonstationary systems can reduce the accuracy of the forecasts and undermine the interpretation of the results. This is problematic because recent studies indicate that sales are often a nonstationary time-series. Newly developed correction techniques can account for nonstationarity by incorporating error-correction terms into the model when using a Bayesian Vector Error-Correction Model. The benefit of using such a technique is that shocks to control variates can be separated into permanent and temporary effects and allow cointegration of series for analysis purposes. Analysis of a brand data set indicates that this is important even at the brand level. Thus, additional information is generated that allows a decision maker to examine controllable variables in terms of whether they influence sales over a short or long duration. Only products that are nonstationary in sales volume can be manipulated for long-term profit gain, and promotions must be cointegrated with brand sales volume. The brand data set is used to explore the capabilities and interpretation of cointegration.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: To investigate whether the recently developed (statistically derived) "ASsessment in Ankylosing Spondylitis Working Group" improvement criteria (ASAS-IC) for ankylosing spondylitis (AS) reflect clinically relevant improvement according to the opinion of an expert panel. Methods: The ASAS-IC consist of four domains: physical function, spinal pain, patient global assessment, and inflammation. Scores on these four domains of 55 patients with AS, who had participated in a non-steroidal anti-inflammatory drug efficacy trial, were presented to an international expert panel (consisting of patients with AS and members of the ASAS Working Group) in a three round Delphi exercise. The number of (non-) responders according to the ASAS-IC was compared with the final-consensus of the experts. The most important domains in the opinion of the experts were identified, and also selected with discriminant analysis. A number of provisional criteria sets that best represented the consensus of the experts were defined. Using other datasets, these clinically derived criteria sets as well as the statistically derived ASAS-IC were then tested for discriminative properties and for agreement with the end of trial efficacy by patient and doctor. Results: Forty experts completed the three Delphi rounds. The experts considered twice as many patients to be responders than the ASAS-IC (42 v 21). Overall agreement between experts and ASAS-IC was 62%. Spinal pain was considered the most important domain by most experts and was also selected as such by discriminant analysis. Provisional criteria sets with an agreement of greater than or equal to 80% compared with the consensus of the experts showed high placebo response rates (27-42%), in contrast with the ASAS-IC with a predefined placebo response rate of 25%. All criteria sets and the ASAS-IC discriminated well between active and placebo treatment (chi(2) = 36-45; p < 0.001). Compared with the end of trial efficacy assessment, the provisional criteria sets showed an agreement of 71-82%, sensitivity of 67-83%, and specificity of 81-88%. The ASAS-IC showed an agreement of 70%, sensitivity of 62%, and specificity of 89%. Conclusion: The ASAS-IC are strict in defining response, are highly specific, and consequently show lower sensitivity than the clinically derived criteria sets. However, those patients who are considered as responders by applying the ASAS-IC are acknowledged as such by the expert panel as well as by. patients' and doctors' judgments, and are therefore likely to be true responders.