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 an article in the <I>Oxford Bulletin of Economics and Statistics</I> (2008). Vol. 70 issue 1, pages 23-51.<P> This paper investigates business cycle relations among different economies in theEuro area. Cyclical dynamics are explicitly modelled as part of a time series...</p></i>

This discussion paper resulted in a publication in the <I>Journal of the Royal Statistical Society Series C</I> (2009). Vol. 58, pages 427-448.<I> Unobserved components time series models decompose a time series into a trend, a season, a cycle, an irregular disturbance, and possibly other components....</i></i>

This discussion paper resulted in an article in the <I>Journal of Financial Econometrics</I> (2012). Vol. 10, pages 354-389.<p> This paper considers spot variance path estimation from datasets of intraday high frequency asset prices in the presence of diurnal variance patterns, jumps, leverage effects and...</p></i>

This discussion paper led to an article in the <I>Journal of Time Series Analysis</I> (2010). Vol. 31, pages 407-414.<P> State space models with nonstationary processes and fixed regression effects require a state vector with diffuse initial conditions. Different likelihood functions can be adopted for...</p></i>

To gain insights in the current status of the economy, macroeconomic time series are often decomposed into trend, cycle and irregular components. This can be done by nonparametric band-pass filtering methods in the frequency domain or by model-based decompositions based on autoregressive moving...

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...

A growing number of empirical studies provides evidence that dynamic properties of macroeconomic time series have been changing over time. Model-based procedures for the measurement of business cycles should therefore allow model parameters to adapt over time. In this paper the time dependencies...

The multivariate analysis of a panel of economic and financial time series with mixed frequencies is a challenging problem. The standard solution is to analyze the mix of monthly and quarterly time series jointly by means of a multivariate dynamic model with a monthly time index: artificial...