NMR in Biomedicine has reached a major turning point. Truman Brown, who has held the North American Editorship since the Journal's foundation in 1987, has had to resign because of pressure of other work. Truman has been involved in every decision we have taken, and has contributed mightily to our su
A classifying procedure for signalling turning points
✍ Scribed by Lasse Koskinen; Lars-Erik Öller
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 368 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0277-6693
- DOI
- 10.1002/for.905
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
A Hidden Markov Model (HMM) is used to classify an out‐of‐sample observation vector into either of two regimes. This leads to a procedure for making probability forecasts for changes of regimes in a time series, i.e. for turning points. Instead of estimating past turning points using maximum likelihood, the model is estimated with respect to known past regimes. This makes it possible to perform feature extraction and estimation for different forecasting horizons. The inference aspect is emphasized by including a penalty for a wrong decision in the cost function. The method, here called a ‘Markov Bayesian Classifier (MBC)’, is tested by forecasting turning points in the Swedish and US economies, using leading data. Clear and early turning point signals are obtained, contrasting favourably with earlier HMM studies. Some theoretical arguments for this are given. Copyright © 2004 John Wiley & Sons, Ltd.
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