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A Comparative Study of Unit Root Tests with Panel Data and a New Simple Test

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Maddala, G. S., Wu, Shaowen·1999·Oxford Bulletin of Economics and Statistics

Abstract

The panel data unit root test suggested by Levin and Lin (LL) has been widely used in several applications, notably in papers on tests of the purchasing power parity hypothesis. This test is based on a very restrictive hypothesis which is rarely ever of interest in practice. The Im–Pesaran–Shin (IPS) test relaxes the restrictive assumption of the LL test. This paper argues that although the IPS test has been offered as a generalization of the LL test, it is best viewed as a test for summarizing the evidence from a number of independent tests of the sample hypothesis. This problem has a long statistical history going back to R. A. Fisher. This paper suggests the Fisher test as a panel data unit root test, compares it with the LL and IPS tests, and the Bonferroni bounds test which is valid for correlated tests. Overall, the evidence points to the Fisher test with bootstrap‐based critical values as the preferred choice. We also suggest the use of the Fisher test for testing stationarity as the null and also in testing for cointegration in panel data.

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Metadata

Authors
Maddala, G. S., & Wu, S.
Venue
Oxford Bulletin of Economics and Statistics
Publisher
Wiley
Published
1999-11
Volume
61
Issue
S1
Pages
631-652
ISSN
  • 0305-9049 (ISSN-L)
  • 1468-0084
OpenAlex
W1969230115
Cited by
7,460
References
2
FWCI
70.13
Type
journal article
Language
en
Open access
bronze

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CoChat. (2026). Citation check: A Comparative Study of Unit Root Tests with Panel Data and a New Simple Test. https://app.cochat.ai/papers/10.1111/1468-0084.0610s1631
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Maddala, G. S., & Wu, S. (1999). A Comparative Study of Unit Root Tests with Panel Data and a New Simple Test. Oxford Bulletin of Economics and Statistics. https://doi.org/10.1111/1468-0084.0610s1631

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