In this paper,we propose a methodology for calculating a leading index of the economic activity based on a modification of Stock and Watson's (1989, 1991, 1992) approach. We use Kalman filter techniques for estimating the state space representation of the leading index model. The methodology is...

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>