Full-text resources of CEJSH and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl

Results found: 4

first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  model comparison
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Publication available in full text mode
Content available

On Some Simulation Procedures for Comparing Nonparametric Methods of Regression

100%
Trzęsiok J., University of Economics in Katowice D. o. M.
Acta Universitatis Lodziensis. Folia Oeconomica
|
2013
|
vol. 286
EN
Nonparametric methods of regression form a large group of varied and rapidly growing methods. In many situations we have a problem with comparing these methods in order to select one of them to solve the regression problem. We present the simulation procedure for comparing the performance of several competing algorithms of nonparametric regression. This procedure has two stages. In the first one, the ranking of nonparametric models of regression is created. In the second stage, statistical test procedures can be used to test the significance of differences in the performances of models presented in the ranking. The procedure is applied to regression benchmark studies based on real world data.
PL
W artykule przedstawiono symulacyjną procedurę badawczą pozwalającą na porównywanie różnych nieparametrycznych modeli regresji, jak i wybór najlepszego z nich. Zaproponowana procedura przebiega dwuetapowo. W pierwszym etapie tworzony jest ranking modeli regresji, pod względem dokładności predykcji, mierzonej za pomocą błędu średniokwadratowego obliczonego metodą sprawdzania krzyżowego ( MSECV ). Drugi etap analizy ma na celu zbadanie istotności różnic pomiędzy uzyskanymi wartościami MSECV , a tym samym skorygowanie otrzymanych rankingów. Do testowania istotności wspomnianych różnic wykorzystano nieparametryczną statystykę testującą zaproponowaną przez Hothorna. Opisaną procedurę badawczą zastosowano w badaniu empirycznym, dla zbiorów danych standardowo wykorzystywanych do analizowania własności różnych metod regresji.
2

Structural Differences and Asymmetric Shocks between the Czech Economy and the Euro Area 12

75%
Slanicay M.
Review of Economic Perspectives
|
2011
|
vol. 11
|
issue 3
168-192
EN
The goal of this paper is to determine whether there exist asymmetric shocks and structural differences between the Czech economy and the Euro Area 12. A New Keynesian DSGE model of a small open economy is used for this purpose. Asymmetric shocks and structural differences are examined in two ways. At first, I examine asymmetry of shocks and sources of structural differences, using model comparison based on the Bayes factor. I do not find substantial evidence in favor of heterogeneity in household preferences. I find slight differences in price and wage formation and substantial difference in interest rate smoothing. However, the main differences are in timing, persistence and volatility of structural shocks. I also investigate impact of structural differences and differences in persistence and volatility of structural shocks on the behavior of both economies, using analysis of impulse-response functions. I find no substantial differences in responses of the main variables to preference shocks. On the other hand, I find much larger volatility and persistence of domestic technology shocks. This contributes to the fact that responses of domestic variables to technology shocks are much larger, and display more gradual and hump-shaped pattern than responses of foreign variables. I also find that responses of foreign variables to labour supply shocks are much more gradual and sluggish than responses of domestic variables. As regards monetary shocks, I find that there is almost no response of foreign inflation to foreign monetary shock while response of domestic inflation to domestic monetary shock displays substantial decline followed by gradual recovery. Responses of foreign variables to cost-push shocks are larger and more volatile than responses of domestic variables.
3

Habit Formation, Price Indexation and Wage Indexation in the DSGE Model: Specification, Estimation and Model Fit

75%
Slanicay M., Vašíček O.
Review of Economic Perspectives
|
2011
|
vol. 11
|
issue 2
71-91
EN
In order to determine which specification provides better fit of the data, this paper presents several specifications of a closed economy DSGE model with nominal rigidities. The goal of this paper is to find out whether some characteristics widely used in New Keynesian DSGE models, such as habit formation in consumption, price indexation and wage indexation, provide better fit of the macroeconomic data. Model specifications are estimated on the data of the US economy and Euro Area 12 economy, using Bayesian techniques, particularly the Metropolis-Hastings algorithm (using Dynare toolbox for Matlab). The data fit measure is a Bayes factor calculated from marginal likelihoods, acquired from Bayesian estimation. Results suggest that including habit formation in consumption significantly improves the empirical data fit of the model, whereas including partial price indexation and partial wage indexation does not improve the empirical data fit of the model. Variants with full price indexation and full wage indexation were the worst ones concerning their data fit.
4
Publication available in full text mode
Content available

Bayesian Analysis of Dynamic Conditional Correlation Using Bivariate GARCH Models

75%
Osiewalski J., Pipień M., Cracow University of Economics D. o. E.
Acta Universitatis Lodziensis. Folia Oeconomica
|
2005
|
vol. 192
EN
Multivariate ARCH-typc specifications provide a theoretically promising framework for analyses of correlation among financial instruments because they can model time-varying conditional covariance matrices. However, general VechGARCH models are too heavily parameterized and, thus, impractical for more than 2- or 3-dimensional vector lime series. A simple t-BEKK(l.l) specification seems a good compromise between parsimony and generality. Unfortunately, Bollerslev’s constant conditional correlation (CCC) model cannot be nested within VECH or BEKK GARCH structures. Recently, Engle (2002) proposed a parsimoniously parameterized generalization of the CCC model; this dynamic conditional correlation (DCC) specification may outperform many older multivariate GARCH models. In this paper we consider Bayesian analysis of the conditional correlation coefficient within different bivariate GARCH models, which are compared using Bayes factors and posterior odds. For daily growth rales of PLN/USD and PLN/DEM (6.02.1996-28.12.2001) we show that the t-BEKK(l, 1) specification fits the bivariate series much better than DCC models, but the posterior means of conditional correlation coefficients obtained within different models are very highly correlated.
PL
Wielowymiarowe specyfikacje ty^pu ARCH stanowią teoretycznie obiecujące ramy dla analiz skorelowania instrumentów finansowych, ponieważ umożliwiają modelowanie zmiennych w czasie macierzy warunkowych kowariancji. Jednak ogólne modele VechGARCH mają zbyt wiele parametrów, są więc niepraktyczne w przypadku więcej niż 2- lub 3-wymiarowych wektorowych szeregów czasowych. Prosta specyfikacja t-BEKK(1,1) wydaje się dobrym kompromisem pomiędzy oszczędnością parametryzacji i ogólnością modelu. Niestety model stałych korelacji warunkowych (CCC) Boilersleva nie jest szczególnym przypadkiem struktur VECH czy BEKK. Ostatnio Englc (2002) zaproponował oszczędnie sparametryzowane uogólnienie modelu CCC; ta specyfikacja o dynamicznej korelacji warunkowej (DCC) może zdominować wiele starszych wielowymiarowych modeli GARCH. W artykule rozważamy bayesowską analizę warunkowego współczynnika korelacji w ramach różnych dwuwymiarowych modeli GARCH, które są porównywane przy użyciu czynników Bayesa i ilorazów szans a posteriori. Dla dziennych stóp zmian kursów PLN/USD i PLN/DEM (6.02.1996 - 28.12.2001) wykazuje się, że specyfikacja t-BEKK(l.l) opisuje dwuwymiarowy szereg czasowy znacznie lepiej niż modele DCC. Jednak wartości oczekiwane a posteriori warunkowych współczynników korelacji, uzyskane w ramach różnych modeli, są bardzo silnie skorelowane.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.