This paper considers a multivariate extension of the test for neglected nonlinearity proposed by Tsay (1986) that uses principal components to overcome the problem of dimensionality that is common with tests of this type. Monte Carlo experiments reveal that the modified multivariate test...

This paper evaluates Czech economic development during 2001 and is supplemented by the predictions of basic economic indicators for 2002 and 2003. This article is divided in several parts. In the beginning we focus on economic growth, including a marginal analysis of GDP and industrial...

This paper evaluates Czech economic development during 2001 and is supplemented by the predictions of basic economic indicators for 2002 and 2003. This article is divided in to several specific parts. In the beginning we focus on economic growth, including a marginal analysis of GDP and...

This paper considers regression-based test criteria for the hypothesis of conditional variance nonstationary in the logarithmic family of GARCH processes. The tests are based on teh ARMA representations that appropriate nonlinear transformations of GARCH-type processes admit. Simulation...

This paper explores the possibility of evaluating the adequacy of Markov-switching time series models by comparing selected functionals (such as the spectral density function and moving empirical moments) obtained from the data with those of the fitted model using a bootstrap algorithm. The...

This paper explores the interactions between cross-sectional aggregation and persistence of volatility shocks. We derive the ARMA-GARCH representation that linear aggregates of ARMA processes with GARCH errors admit, and establish conditions under which persistence in volatility of the aggregate...

This paper investigates the presence of target-zone nonlinearities in the Pound Sterling/Deutsche Mark exchange rate for the period of the UK European Exchange Rate Mechanism (ERM) membership, using data with frequency of every two days. Tests against general nonlinear specifications as well as...