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PPP May not Hold Afterall: A Further Investigation

Author

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  • Serena Ng

    (Department of Economics, Johns Hopkins University)

  • Pierre Perron

    (Department of Economics, Boston University)

Abstract

In a recent paper, Engel, C. (1999) presents monte-carlo evidence to suggest that unit root tests cannot detect a non-stationary component in the real exchange rate even when this component accounts for almost half of its longhorizon forecast error variance. This hidden non-stationary component led to the conclusion that long run purchasing power parity might not hold afterall. In this note, we first point out some conceptual difficulties with the statistic being used to measure the size of the non-stationary component, and then argue that it bears no systematic relationship with rejection rates in unit root tests. The problems stem from near observational equivalence of the simulated model in not one, but two dimensions. We then discuss the steps a practitioner can take to minimize Type I error in cases when the non-stationary component is hard to detect. Real exchange rate data for 19 countries are examined and estimates are obtained for the duration of the real exchange rate shocks.

Suggested Citation

  • Serena Ng & Pierre Perron, 2002. "PPP May not Hold Afterall: A Further Investigation," CEMA Working Papers 83, China Economics and Management Academy, Central University of Finance and Economics.
    • Handle: RePEc:cuf:wpaper:83
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    References listed on IDEAS

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    Citations

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    Cited by:

    1. Lee, Hwa-Taek & Yoon, Gawon, 2007. "Does Purchasing Power Parity Hold Sometimes? Regime Switching in Real Exchange Rates," Economics Working Papers 2007-24, Christian-Albrechts-University of Kiel, Department of Economics.
    2. Maican, Florin G. & Sweeney, Richard J., 2013. "Real exchange rate adjustment in European transition countries," Journal of Banking & Finance, Elsevier, vol. 37(3), pages 907-926.
    3. Hong, Seung Hyun & Phillips, Peter C. B., 2010. "Testing Linearity in Cointegrating Relations With an Application to Purchasing Power Parity," Journal of Business & Economic Statistics, American Statistical Association, vol. 28(1), pages 96-114.
    4. Franses, Ph.H.B.F. & van Dijk, D.J.C., 2002. "A simple test for PPP among traded goods," Econometric Institute Research Papers EI 2002-02, Erasmus University Rotterdam, Erasmus School of Economics (ESE), Econometric Institute.
    5. De-Chih Liu, 2011. "Hysteresis Hypothesis in Job Creation and Destruction: Evidence from the U.S," Annals of Economics and Finance, Society for AEF, vol. 12(2), pages 389-409, November.
    6. Jaramillo Franco, Miguel & Serván Lozano, Sergio, 2012. "Modeling exchange rate dynamics in Peru: A cointegration approach using the UIP and PPP," MPRA Paper 70772, University Library of Munich, Germany.
    7. Alan M. Taylor, 2002. "A Century Of Purchasing-Power Parity," The Review of Economics and Statistics, MIT Press, vol. 84(1), pages 139-150, February.
    8. Mazzotta, Stefano, 2008. "How important is asymmetric covariance for the risk premium of international assets?," Journal of Banking & Finance, Elsevier, vol. 32(8), pages 1636-1647, August.
    9. Frederic Bec & Melika Ben Salem & Marine Carrasco, 2004. "Tests for Unit-Root versus Threshold Specification With an Application to the Purchasing Power Parity Relationship," Journal of Business & Economic Statistics, American Statistical Association, vol. 22, pages 382-395, October.
    10. Emmanuel Anoruo & Habtu Braha, 2008. "Housing and Stock Market Returns: An Application of GARCH Enhanced VECM," The IUP Journal of Financial Economics, IUP Publications, vol. 0(2), pages 30-40, June.
    11. de Andrade, Joaquim Pinto & Divino, Jose Angelo, 2005. "Monetary policy of the Bank of Japan--inflation target versus exchange rate target," Japan and the World Economy, Elsevier, vol. 17(2), pages 189-208, April.
    12. Gawon Yoon, 2003. "The time series behaviour of Brazilian inflation rate: new evidence from unit root tests with good size and power," Applied Economics Letters, Taylor & Francis Journals, vol. 10(10), pages 627-631.
    13. Hwa-Taek Lee & Gawon Yoon, 2013. "Does purchasing power parity hold sometimes? Regime switching in real exchange rates," Applied Economics, Taylor & Francis Journals, vol. 45(16), pages 2279-2294, June.
    14. Mehmet Balcilar & Rangan Gupta & Charl Jooste, 2016. "Analyzing South Africa’s inflation persistence using an ARFIMA model with Markov-switching fractional differencing parameter," Journal of Developing Areas, Tennessee State University, College of Business, vol. 50(1), pages 47-57, January-M.
    15. David O. Cushman, 2008. "Real exchange rates may have nonlinear trends," International Journal of Finance & Economics, John Wiley & Sons, Ltd., vol. 13(2), pages 158-173.
    16. Christoph Fischer & Daniel Porath, 2010. "A reappraisal of the evidence on PPP: a systematic investigation into MA roots in panel unit root tests and their implications," Empirical Economics, Springer, vol. 39(3), pages 767-792, December.
    17. Sofiane H. Sekioua, 2004. "Real interest parity (RIP) over the 20th century: New evidence based on confidence intervals for the dominant root and half-lives of shocks," Money Macro and Finance (MMF) Research Group Conference 2004 91, Money Macro and Finance Research Group.

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    More about this item

    Keywords

    PPP; Monte-carlo; Unit root;
    All these keywords.

    JEL classification:

    • F30 - International Economics - - International Finance - - - General
    • F40 - International Economics - - Macroeconomic Aspects of International Trade and Finance - - - General
    • C2 - Mathematical and Quantitative Methods - - Single Equation Models; Single Variables
    • C3 - Mathematical and Quantitative Methods - - Multiple or Simultaneous Equation Models; Multiple Variables
    • C5 - Mathematical and Quantitative Methods - - Econometric Modeling

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