The serial dependence of categorical data is commonly described using Markovian models. Such models are very flexible, but they can suffer from a huge number of parameters if the state space or the model order becomes large. To address the problem of a large number of model parameters, the class...

In regression we can delete outliers based upon a preliminary estimator and re-estimate the parameters by least squares based upon the retained observations. We study the properties of an iteratively defined sequence of estimators based on this idea. We relate the sequence to the Huber-skip...

This study reconsiders the common unit root/co-integration approach to test for the Fisher effect for the economies of the G7 countries. We first show that nominal interest and inflation rates are better represented as I(0) variables. Later, we use the Bai-Perron procedure to show the existence...

SURGAT is a RATS menu-driven program to help in the analysis of the seasonal component and the trend of a (quarterly, monthly or annual) time series. Once the series is selected, a set of simple transformations may be applied: log, regular difference, seasonal difference, regular+seasonal...

In regression we can delete outliers based upon a preliminary estimator and re-estimate the parameters by least squares based upon the retained observations. We study the properties of an iteratively defined sequence of estimators based on this idea. We relate the sequence to the Huber-skip...

This paper challenges the commonly used unit root/cointegration approach for testing the Fisher effect for the economies of the G7 countries. We first prove that nominal interest and inflation rate can be better represented as being broken trend stationary variables. Later, we use the Bai-Perron...

This paper studies the behavior of the HEGY statistics for quarterly data, for seasonal autoregressive unit roots, when the analyzed time series is deterministic seasonal stationary but exhibits a change in the seasonal pattern. As a by-product we analyze also the HEGY test for the nonseasonal...

We develop and discuss a parameterization of vector autoregressive moving average processes with arbitrary unit roots and (co)integration orders. The detailed analysis of the topological properties of the parameterization - based on the state space canonical form of Bauer and Wagner (2012) - is...