Finite-Sample Properties of the GLS-Based Dickey-Fuller Test in the Presence of Breaks in Innovation Variance

Using local-to-unity detrending, the GLS-based Dickey-Fuller test has been shown to possess higher power than other available unit root tests. As a result, application of this easily implemented test has increased in recent years. In the present study the finite-sample size and power of the GLS-base...

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Bibliographic Details
Main Author: Steven Cook
Format: Article
Language:English
Published: Austrian Statistical Society 2016-04-01
Series:Austrian Journal of Statistics
Online Access:http://www.ajs.or.at/index.php/ajs/article/view/444
Description
Summary:Using local-to-unity detrending, the GLS-based Dickey-Fuller test has been shown to possess higher power than other available unit root tests. As a result, application of this easily implemented test has increased in recent years. In the present study the finite-sample size and power of the GLS-based Dickey-Fuller test is examined in the presence of breaks in innovation variance under the null. In contrast to the original Dickey-Fuller test which has been shown to suffer severe distortion in such circumstances, the GLS-based test latter exhibits robustness to all but the most extreme breaks in variance. The results derived show the GLS-based test to be more robust to variance breaks than other modified Dickey-Fuller tests previously considered in the literature.
ISSN:1026-597X