In this paper we investigate whether the dynamic properties of the U.S. business cycle have changed in the last fifty years. For this purpose we develop a flexible business cycle indicator that is constructed from a moderate set of macroeconomic time series. The coincident economic indicator is...

We use an intensity-based framework to study the relation between macroeconomic fundamentals and cycles in defaults and rating activity. Using Standard and Poor's U.S. corporate rating transition and default data over the period 1980-2005, we directly estimate the default and rating cycle from...

This discussion paper led to a publication in the <I>Electronic Journal of Statistics</I> (2014). Vol. 8, pages 1088-1112.<P> We characterize the dynamic properties of Generalized Autoregressive Score (GAS) processes by identifying regions of the parameter space that imply stationarity and ergodicity. We...</p></i>

Although the main interest in the modelling of electricity prices is often on volatility aspects, we argue that stochastic heteroskedastic behaviour in prices can only be modelled correctly when the conditional mean of the time series is properly modelled. In this paper we consider different...

The Commonwealth of Virginia abolished parole and reformed sentencing for all felony of-fenders committed on or after January 1, 1995. We examine the impact of this legislationon reported crime rates using different time series approaches. In particular, structuraltime series models are...

This discussion paper resulted in a publication in <I>Computational Statistics & Data Analysis</I> (2006). Vol. 51, issue 2, pages 885-903.<P> We explore a periodic analysis in the context of unobserved components time series models that decompose time series into components of interest such as trend and...</p></i>

We propose a new Markov switching model with time varying probabilities for the transitions. The novelty of our model is that the transition probabilities evolve over time by means of an observation driven model. The innovation of the time varying probability is generated by the score of the...

This discussion paper led to a publication in the <I>International Journal of Forecasting</I> (2013). Vol. 29, pages 676-694.<P> We extend the class of dynamic factor yield curve models for the inclusion of macro-economic factors. We benefit from recent developments in the dynamic factor literature for...</p></i>

We introduce a dynamic statistical model for Skellam distributed random variables. The Skellam distribution can be obtained by taking differences between two Poisson distributed random variables. We treat cases where observations are measured over time and where possible serial correlation is...