The main failure of ARIMA modelling as used in practice are the limiting constraints imposed by differencing to achieve stationarity. The use of fractional differencing opens up a much wider and realistic behaviour for the trend and seasonal components than traditional integer differencing. This pap
Time series forecasting using robust regression
โ Scribed by Hans Levenbach
- Publisher
- John Wiley and Sons
- Year
- 1982
- Tongue
- English
- Weight
- 710 KB
- Volume
- 1
- Category
- Article
- ISSN
- 0277-6693
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
The method of ordinary least squares (OLS) and generalizations of it have been the mainstay of most forecasting methodologies for many years. It is wellโknown, however, that outliers or unusual values can have a large influence on leastโsquares estimators. Users of automatic forecasting packages, in particular, need to be aware of the influence that outlying data values can have on statistical analyses and forecasting results. Robust methods are available to modify leastโsquares procedures so that outliers have much less influence on the final estimates; yet these formal methods have not found their way into general forecasting procedures. This paper provides a case study in which classical leastโsquareโestimation procedures are complemented with a robust alternative to enhance statistical fit criteria and improve forecasting performance. The study suggests that much can be gained in understanding the nature of outliers and their influence on forecasting performance by performing a robust regression in addition to OLS.
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