Abstract: Grandmont (1985) found that the parameter space of the most classical dynamic general-equilibrium macroeconomic models are stratified into an infinite number of subsets supporting an infinite number of different kinds of dynamics, from monotonic stability at one extreme to chaos at the...

The paper deals with the detection and measurement of the level of persistence on aggregate private consumption in Portugal, USA, European Union and EuroZone as well as on some categories of aggregate consumption in Portugal. By the use of a non-parametric methodology applied to monthly data...

The paper concerns the design of nonparametric low-pass filters that have the property of reproducing a polynomial of a given degree. Two approaches are considered. The first is locally weighted polynomial regression (LWPR), which leads to linear filters depending on three parameters: the...

A class of semiparametric fractional autoregressive GARCH models (SEMIFAR-GARCH), which includes deterministic trends, difference stationarity and stationarity with short- and long-range dependence, and heteroskedastic model errors, is very powerful for modelling financial time series. This...

In studying the scale invariance of an empirical time series a twofold problem arises: it is necessary to test the series for self-similarity and, once passed such a test, the goal becomes to estimate the parameter H0 of self-similarity. The estimation is therefore correct only if the sequence...

We introduce a two-step procedure for more efficient nonparametric prediction of a strictly stationary process admitting an ARMA representation. The procedure is based on the estimation of the ARMA representation, followed by a nonparametric regression where the ARMA residuals are used as...

Atheoretical regression trees (ART) are applied to detect changes in the mean of a stationary long memory time series when location and number are unknown. It is shown that the BIC, which is almost always used as a pruning method, does not operate well in the long memory framework. A new method...

The detection and measurement of the level of persistence on aggregate and disaggregate private consumption in Italy, Norway and United Kingdom is the main focus of the paper. Using a non-parametric methodology applied to annual data it is concluded that that one cannot reject the presence of a...

The detection and measurement of the level of persistence on aggregate and disaggregate private consumption in Italy, Norway and United Kingdom are the main focus of the paper. Using a non-parametric methodology it is concluded that we cannot reject the presence of a significant degree of...

I describe preliminary results for seasonal decomposition procedure using a modified Hodrick-Prescott (Leser) filter. The procedure is simpler to implement compared to two currently most popular seasonal decomposition procedures - X-11 filters developed by the U.S. Census Bureau and SEATS...