Template-Type: ReDIF-Paper 1.0 Series: Tinbergen Institute Discussion Papers Creation-Date: 2010-02-03 Number: 10-017/4 Author-Name: Charles S. Bos Author-Email: cbos@feweb.vu.nl Author-Workplace-Name: VU University Amsterdam Author-Name: Siem Jan Koopman Author-Email: s.j.koopman@feweb.vu.nl Author-Workplace-Name: VU University Amsterdam Title: Models with Time-varying Mean and Variance: A Robust Analysis of U.S. Industrial Production Abstract: Many seasonal macroeconomic time series are subject to changes in their means and variances over a long time horizon. In this paper we propose a general treatment for the modelling of time-varying features in economic time series. We show that time series models with mean and variance functions depending on dynamic stochastic processes can be sufficiently robust against changes in their dynamic properties. We further show that the implementation of the treatment is relatively straightforward. An illustration is given for monthly U.S. Industrial Production. The empirical results including estimates of time-varying means and variances are discussed in detail. Classification-JEL: C22, C51, C53, E23 Keywords: Common stochastic variance, Kalman filter, State space model, unobserved components time series model File-Url: https://papers.tinbergen.nl/10017.pdf File-Format: application/pdf File-Size: 316441 bytes Handle: RePEc:tin:wpaper:20100017