IDEAS home Printed from https://ideas.repec.org/p/hhs/vxcafo/2009_007.html
   My bibliography  Save this paper

Wavelet Improvement of the Over-rejection of Unit root test under GARCH errors

Author

Listed:
  • Li, Yushu

    () (Centre for Labour Market Policy Research (CAFO))

  • Shukur, Ghazi

    () (Centre for Labour Market Policy Research (CAFO))

Abstract

In this paper, we use the wavelet technique to improve the over-rejection problem of the traditional Dickey-Fuller test for unit root when the data suffers from GARCH (1,1) effect. The logic is based on that the wavelet spectrum decomposition can separate out information of different frequencies in the data series. We prove that the asymptotic distribution of our test is similar to the traditional Dickey-Fuller(1979 and 1981) type of tests. The small sample distribution of the new test is assessed by means of Monte Carlo simulation. An empirical example with data on immigration to Sweden during the period 1950 to 2000 is used to illustrate the test. The results reveal that using the traditional Dickey-Fuller type of test, the unit root is rejected while our wavelet improved test shows the opposite result.

Suggested Citation

  • Li, Yushu & Shukur, Ghazi, 2009. "Wavelet Improvement of the Over-rejection of Unit root test under GARCH errors," CAFO Working Papers 2009:7, Linnaeus University, Centre for Labour Market Policy Research (CAFO), School of Business and Economics.
  • Handle: RePEc:hhs:vxcafo:2009_007
    as

    Download full text from publisher

    File URL: http://www.vxu.se/ehv/filer/forskning/cafo/wps/Nek_wp7_09.pdf
    Download Restriction: no

    References listed on IDEAS

    as
    1. Dickey, David A & Fuller, Wayne A, 1981. "Likelihood Ratio Statistics for Autoregressive Time Series with a Unit Root," Econometrica, Econometric Society, vol. 49(4), pages 1057-1072, June.
    2. Ling, Shiqing & Li, W.K., 2003. "Asymptotic Inference For Unit Root Processes With Garch(1,1) Errors," Econometric Theory, Cambridge University Press, vol. 19(04), pages 541-564, August.
    3. Seo, Byeongseon, 1999. "Distribution theory for unit root tests with conditional heteroskedasticity1," Journal of Econometrics, Elsevier, vol. 91(1), pages 113-144, July.
    Full references (including those not matched with items on IDEAS)

    More about this item

    Keywords

    Dickey-Fuller test; GARCH (1:1); Wavelet spectrum decomposition; MODWT;

    JEL classification:

    • C15 - Mathematical and Quantitative Methods - - Econometric and Statistical Methods and Methodology: General - - - Statistical Simulation Methods: General
    • C52 - Mathematical and Quantitative Methods - - Econometric Modeling - - - Model Evaluation, Validation, and Selection

    NEP fields

    This paper has been announced in the following NEP Reports:

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:hhs:vxcafo:2009_007. See general information about how to correct material in RePEc.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Andreas MÃ¥ngs). General contact details of provider: http://edirc.repec.org/data/cafovse.html .

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service hosted by the Research Division of the Federal Reserve Bank of St. Louis . RePEc uses bibliographic data supplied by the respective publishers.