The problem of estimating unknown observational variances in multivariate dynamic linear models is considered. Conjugate procedures are possible for univariate models and also for special very restrictive common components models but they are not generally applicable. However, for clarity of operati
Covariance estimation for multivariate conditionally Gaussian dynamic linear models
β Scribed by K. Triantafyllopoulos
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 245 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0277-6693
- DOI
- 10.1002/for.1039
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β¦ Synopsis
Abstract
In multivariate time series, estimation of the covariance matrix of observation innovations plays an important role in forecasting as it enables computation of standardized forecast error vectors as well as the computation of confidence bounds of forecasts. We develop an online, nonβiterative Bayesian algorithm for estimation and forecasting. It is empirically found that, for a range of simulated time series, the proposed covariance estimator has good performance converging to the true values of the unknown observation covariance matrix. Over a simulated time series, the new method approximates the correct estimates, produced by a nonβsequential Monte Carlo simulation procedure, which is used here as the gold standard. The special, but important, vector autoregressive (VAR) and timeβvarying VAR models are illustrated by considering London metal exchange data consisting of spot prices of aluminium, copper, lead and zinc.βCopyright Β© 2007 John Wiley & Sons, Ltd.
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