Short Memory and the PPP-puzzle
AbstractThe so-called purchasing-power parity (PPP) puzzle takes one of two forms. In its first form, early tests of the PPP-hypothesis failed to reject unit roots in real exchange rates, thus rejecting the hypothesis of PPP holding in the long term. In the more recent literature, the literature on the PPP puzzle focused on stochastic real exchange rate models that allow long term PPP to hold. However, early estimates of such models suggested that the real exchange rates converge to their long-term PPP levels at a very slow rate (usually expressed as a half-life of 3~5 years), c.f. Rogoff (1996). Attempts to solve the second form of the PPP-puzzle have been forthcoming in recent years, mostly by using non-linear stochastic models of real exchange rates. However, despite the introduction of non-linearities, the literature has continued to focus on the notion of "half-life" as a measure of persistence. We argue the half-life measure is only appropriate in linear settings, failing to capture the richness of non-linear dynamics introduced in the more recent literature. We propose operational measures of persistence in such non-linear models, which we label short-memory in distribution (SMD, which is similar to the notion of -mixing), and short-memory in mean (SMM, c.f. Granger (1995)). We show that focusing on a simple notion such as "half-life" can be very misleading. In particular, we show that it is possible to match desired "half-lives" for any of the most popular non-linear models recently proposed in the literature. However, we show that those models imply very different persistent properties for the same half-life. We conclude that depending on the models and criteria selected for investigating the PPP puzzle, the puzzle may be in the eye of the beholder.
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PPP-puzzle; half-life; SMD; SMM; phi-mixing; persistence measure; cross-validation; non-parametric times series analysis; Markov models;
Find related papers by JEL classification:
- C1 - Mathematical and Quantitative Methods - - Econometric and Statistical Methods and Methodology: General
- F0 - International Economics - - General
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- Quah, Danny, 1993.
"Empirical cross-section dynamics in economic growth,"
European Economic Review,
Elsevier, vol. 37(2-3), pages 426-434, April.
- Danny Quah, 1992. "Empirical cross-section dynamics in economic growth," Discussion Paper / Institute for Empirical Macroeconomics 75, Federal Reserve Bank of Minneapolis.
- Danny Quah, 1992. "Empirical Cross-Section Dynamics in Economic Growth," FMG Discussion Papers dp154, Financial Markets Group.
- Domowitz, Ian & El-Gamal, Mahmoud A., 1993.
"A Consistent Test of Stationary Ergodicity,"
794, California Institute of Technology, Division of the Humanities and Social Sciences.
- Kenneth A. Froot & Kenneth Rogoff, 1994.
"Perspectives on PPP and Long-Run Real Exchange Rates,"
NBER Working Papers
4952, National Bureau of Economic Research, Inc.
- Froot, Kenneth A. & Rogoff, Kenneth, 1995. "Perspectives on PPP and long-run real exchange rates," Handbook of International Economics, in: G. M. Grossman & K. Rogoff (ed.), Handbook of International Economics, edition 1, volume 3, chapter 32, pages 1647-1688 Elsevier.
- Ken Froot & Kenneth Rogoff, . "Perspectives on PPP and Long-Run Real Exchange Rates," Working Paper 32027, Harvard University OpenScholar.
- Mototsugu Shintani, 2002.
"A Nonparametric Measure of Convergence Toward Purchasing Power Parity,"
Vanderbilt University Department of Economics Working Papers
0219, Vanderbilt University Department of Economics, revised Jul 2004.
- Mototsugu Shintani, 2006. "A nonparametric measure of convergence towards purchasing power parity," Journal of Applied Econometrics, John Wiley & Sons, Ltd., vol. 21(5), pages 589-604.
- Mototsugu Shintani, 2003. "A Nonparametric Measure of Convergence Toward Purchasing Power Parity," Levine's Working Paper Archive 506439000000000172, David K. Levine.
- Michael, Panos & Nobay, A Robert & Peel, David A, 1997.
"Transactions Costs and Nonlinear Adjustment in Real Exchange Rates: An Empirical Investigation,"
Journal of Political Economy,
University of Chicago Press, vol. 105(4), pages 862-79, August.
- Tom Doan, . "RATS programs to replicate Michael-Nobay-Peel ESTAR models," Statistical Software Components RTZ00113, Boston College Department of Economics.
- Sarno, Lucio & Taylor, Mark P, 1997.
"The Behaviour of Real Exchange Rates During the Post-Bretton Woods Period,"
CEPR Discussion Papers
1730, C.E.P.R. Discussion Papers.
- Taylor, Mark P. & Sarno, Lucio, 1998. "The behavior of real exchange rates during the post-Bretton Woods period," Journal of International Economics, Elsevier, vol. 46(2), pages 281-312, December.
- Day, Richard H. & Pianigiani, Giulio, 1991. "Statistical Dynamics and Economics," Working Paper Series 293, Research Institute of Industrial Economics.
- Obstfeld, Maurice & Taylor, Alan M., 1997.
"Nonlinear Aspects of Goods-Market Arbitrage and Adjustment: Heckscher's Commodity Points Revisited,"
Journal of the Japanese and International Economies,
Elsevier, vol. 11(4), pages 441-479, December.
- Maurice Obstfeld and Alan M. Taylor., 1997. "Nonlinear Aspects of Goods-Market Arbitrage and Adjustment: Heckscher's Commodity Points Revisited," Center for International and Development Economics Research (CIDER) Working Papers C97-088, University of California at Berkeley.
- Obstfeld, Maurice & Taylor, Alan M, 1997. "Nonlinear Aspects of Goods-Market Arbitrage and Adjustment: Heckscher's Commodity Points Revisited," CEPR Discussion Papers 1672, C.E.P.R. Discussion Papers.
- Maurice Obstfeld & Alan M. Taylor, 1997. "Nonlinear Aspects of Goods-Market Arbitrage and Adjustment: Heckscher's Commodity Points Revisited," NBER Working Papers 6053, National Bureau of Economic Research, Inc.
- Papell, David H. & Theodoridis, Hristos, 1998. "Increasing evidence of purchasing power parity over the current float," Journal of International Money and Finance, Elsevier, vol. 17(1), pages 41-50, February.
- Michael R. Darby, 1983. "Movements in Purchasing Power Parity: The Short and Long Runs," NBER Chapters, in: The International Transmission of Inflation, pages 462-477 National Bureau of Economic Research, Inc.
- Sala-i-Martin, Xavier X, 1996.
"The Classical Approach to Convergence Analysis,"
Royal Economic Society, vol. 106(437), pages 1019-36, July.
- Sala-i-Martin, Xavier, 1995. "The Classical Approach to Convergence Analysis," CEPR Discussion Papers 1254, C.E.P.R. Discussion Papers.
- Xavier Sala-i-Martin, 1995. "The classical approach to convergence analysis," Economics Working Papers 117, Department of Economics and Business, Universitat Pompeu Fabra.
- Sala-i-martin, X., 1995. "The Classical Approach to Convergence Analysis," Papers 734, Yale - Economic Growth Center.
- Domowitz, Ian & El-Gamal, Mahmoud A., 2001.
"A consistent nonparametric test of ergodicity for time series with applications,"
Journal of Econometrics,
Elsevier, vol. 102(2), pages 365-398, June.
- Mankiw, N Gregory & Romer, David & Weil, David N, 1992.
"A Contribution to the Empirics of Economic Growth,"
The Quarterly Journal of Economics,
MIT Press, vol. 107(2), pages 407-37, May.
- Baum, Christopher F. & Barkoulas, John T. & Caglayan, Mustafa, 2001.
"Nonlinear adjustment to purchasing power parity in the post-Bretton Woods era,"
Journal of International Money and Finance,
Elsevier, vol. 20(3), pages 379-399, June.
- Christopher F. Baum & Mustafa Caglayan & John Barkoulas, 1998. "Nonlinear Adjustment to Purchasing Power Parity in the post-Bretton Woods Era," Boston College Working Papers in Economics 404., Boston College Department of Economics, revised 16 Nov 1999.
- White, Halbert & Domowitz, Ian, 1984. "Nonlinear Regression with Dependent Observations," Econometrica, Econometric Society, vol. 52(1), pages 143-61, January.
- Taylor, Mark P & Peel, David A & Sarno, Lucio, 2001.
"Nonlinear Mean-Reversion in Real Exchange Rates: Toward a Solution to the Purchasing Power Parity Puzzles,"
International Economic Review,
Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 42(4), pages 1015-42, November.
- Peel, David & Sarno, Lucio & Taylor, Mark P, 2001. "Nonlinear Mean-Reversion in Real Exchange Rates: Towards a Solution to the Purchasing Power Parity Puzzles," CEPR Discussion Papers 2658, C.E.P.R. Discussion Papers.
- Steven N. Durlauf, 1991.
"Nonergodic Economic Growth,"
NBER Working Papers
3719, National Bureau of Economic Research, Inc.
- Day, Richard H. & Pianigiani, Giulio, 1991. "Statistical dynamics and economics," Journal of Economic Behavior & Organization, Elsevier, vol. 16(1-2), pages 37-83, July.
- Lothian, James R & Taylor, Mark P, 1996. "Real Exchange Rate Behavior: The Recent Float from the Perspective of the Past Two Centuries," Journal of Political Economy, University of Chicago Press, vol. 104(3), pages 488-509, June.
- Papell, David H., 1997. "Searching for stationarity: Purchasing power parity under the current float," Journal of International Economics, Elsevier, vol. 43(3-4), pages 313-332, November.
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