Asymptotic behaviour of tests for a unit root against an explosive alternative

We compare the asymptotic local power of upper-tail unit root tests against an explosive alternative based on ordinary least squares (OLS) and quasi-differenced (QD) demeaning/detrending. We find that under an asymptotically negligible initialisation, the QD-based tests are near asymptotically effic...

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Main Authors: Harvey, David I., Leybourne, Stephen J.
Format: Article
Published: Elsevier 2014
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Online Access:https://eprints.nottingham.ac.uk/32668/
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author Harvey, David I.
Leybourne, Stephen J.
author_facet Harvey, David I.
Leybourne, Stephen J.
author_sort Harvey, David I.
building Nottingham Research Data Repository
collection Online Access
description We compare the asymptotic local power of upper-tail unit root tests against an explosive alternative based on ordinary least squares (OLS) and quasi-differenced (QD) demeaning/detrending. We find that under an asymptotically negligible initialisation, the QD-based tests are near asymptotically efficient and generally offer superior power to OLS-based approaches; however, the power gains are much more modest than in the lower-tail testing context. We also find that asymptotically non-negligible initial conditions do not affect the power ranking in the same way as they do for lower-tail tests, with the QD-based tests retaining a power advantage in such cases.
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spelling nottingham-326682020-05-04T20:15:44Z https://eprints.nottingham.ac.uk/32668/ Asymptotic behaviour of tests for a unit root against an explosive alternative Harvey, David I. Leybourne, Stephen J. We compare the asymptotic local power of upper-tail unit root tests against an explosive alternative based on ordinary least squares (OLS) and quasi-differenced (QD) demeaning/detrending. We find that under an asymptotically negligible initialisation, the QD-based tests are near asymptotically efficient and generally offer superior power to OLS-based approaches; however, the power gains are much more modest than in the lower-tail testing context. We also find that asymptotically non-negligible initial conditions do not affect the power ranking in the same way as they do for lower-tail tests, with the QD-based tests retaining a power advantage in such cases. Elsevier 2014-01 Article PeerReviewed Harvey, David I. and Leybourne, Stephen J. (2014) Asymptotic behaviour of tests for a unit root against an explosive alternative. Economics Letters, 122 (1). pp. 64-68. ISSN 0165-1765 Unit root testing; Explosive autoregression; Asymptotic power; Initial condition http://www.sciencedirect.com/science/article/pii/S016517651300493X doi:10.1016/j.econlet.2013.11.006 doi:10.1016/j.econlet.2013.11.006
spellingShingle Unit root testing; Explosive autoregression; Asymptotic power; Initial condition
Harvey, David I.
Leybourne, Stephen J.
Asymptotic behaviour of tests for a unit root against an explosive alternative
title Asymptotic behaviour of tests for a unit root against an explosive alternative
title_full Asymptotic behaviour of tests for a unit root against an explosive alternative
title_fullStr Asymptotic behaviour of tests for a unit root against an explosive alternative
title_full_unstemmed Asymptotic behaviour of tests for a unit root against an explosive alternative
title_short Asymptotic behaviour of tests for a unit root against an explosive alternative
title_sort asymptotic behaviour of tests for a unit root against an explosive alternative
topic Unit root testing; Explosive autoregression; Asymptotic power; Initial condition
url https://eprints.nottingham.ac.uk/32668/
https://eprints.nottingham.ac.uk/32668/
https://eprints.nottingham.ac.uk/32668/