Purchasing power parity in ASEAN-5 countries: revisit with cross-sectional dependence and structural breaks

This paper re-examines the purchasing power parity (PPP) hypothesis for a panel of ASEAN-5 countries. The panel unit root and cointegration tests, which incorporate cross-sectional dependence and multiple structural breaks, are innovatively used for testing the PPP hypothesis. We could not find evidence that supports the existence of a long-run equilibrium between the relative price ratio and the nominal exchange rate for the whole period. Nevertheless, there is evidence of a cointegrating relationship for the post-crisis period. Our finding implies that a flexible exchange rate regime is suitable for the individual ASEAN countries.     

Getting PPP right: Identifying mean-reverting real exchange rates in panels

Recent advances in testing for the validity of Purchasing Power Parity (PPP) focus on the time series properties of real exchange rates in panel frameworks. One weakness of such tests, however, is that they fail to inform the researcher as to which cross-section units are stationary. As a consequence, a reservation for PPP analyses based on such tests is that a small number of real exchange rates in a given panel may drive the results. In this paper we examine the PPP hypothesis focusing on the stationarity of the real exchange rates in up to 25 OECD countries. We introduce a methodology that when applied to a set of established panel unit-root tests, allows the identification of the real exchange rates that are stationary. Our results reveal evidence of mean-reversion that is significantly stronger as compared to that obtained by the existing literature, strengthening the case for PPP.     

Testing PPP Hypotheses between Japan and the Six G7 Countries

The paper examines the purchasing power parity(PPP) theory of the foreign exchange rate of the yenagainst the currencies of the six G7 countries. We usethe error-corrected five-dimensional vectorautoregressive (VAR) model with structural changes inthe trend function. The data cover the period of thepost-Breton–Woods floating exchange rate system. Theresults reveal that the PPP relation alone determinesthe exchange rates for the USA, France, Germany, andItaly, while a linear combination of PPP and uncoveredinterest rate parity (UIP) relations determines that for Canada. Ina model without trend breaks, the PPP relations holdonly for Germany, which indicates that a correctspecification of the sampling distribution of data isimportant. The one-step prediction based on the errorcorrection model (ECM) outperforms the random walkmodel. The ECM is useful to predict the out-of-samplebehaviors of the exchange rates.     

购买力平价理论的实证检验法综述

本文介绍了自 2 0世纪 70年代以来开放经济理论的基石———购买力平价及实际汇率的相关实证检验方法。以发达国家双边汇率作为样本数据进行检验 ,发现在样本期间足够长、样本数量足够多的情况下 ,PPP假设成立。此外 ,由于实际汇率对PPP的均值复归呈现出显著的非线性特征 ,今后的研究方向应当是建立非线性汇率动态模型。     

Searching for evidence of long-run PPP from a post-Bretton Woods panel: separating the wheat from the chaff

This paper reexamines the issue of long-run PPP using multiple panel tests in the framework of confirmatory analysis. Application of six panel tests under competing null hypotheses to the real exchange rates of 21 industrial countries yields seemingly contradictory evidence on the parity during the post-Bretton Woods period. Regardless of numeraire currency, four I(1) panel tests unanimously reject the null hypothesis in favor of long-run PPP, whereas two I(0) panel tests lend little support to the parity at conventional significance levels. Confirmatory analysis suggests that this puzzling result can be explained either by nonlinear dynamics of the real exchange rates or by a mixture of I(0) and I(1) series in the panel. Monte Carlo experiments indicate that potential mix of I(0) and I(1) series is more relevant to the empirical finding. The use of a sequential classification method sorts out six real exchange rates which exhibit most persistent deviations from long-run equilibrium. Systematic behavior of these series can be characterized better by country specific factors than by observable macroeconomic variables.     

A structural time series test of the monetary model of exchange rates under the German hyperinflation

In this paper some structural time series evidence is presented for the monetary model of exchange rates under the German hyperinflation. The results show that the money supply and the expected rate of change of the exchange rate played a dominant role in the determination of the exchange rate of the mark against the US dollar. The results also support the property of proportionality between the exchange rate and the money supply. Furthermore, evidence is found for the validity of the constituent components of the monetary model, PPP and the quantity theory.     

A test of purchasing power parity for emerging economies

The concept of purchasing power parity (PPP) is examined here for its applicability to the soft currencies of a large group of emerging/developing economies. PPP is tested through the use of the technique of cointegration. Based on data covering the period of 1975–1997, cointegration tests of price indices and exchange rates are conducted for 27 countries (against the U. S.). The results provide relatively strong evidence (for 14 countries) in favor of the long-term applicability of PPP as a cointegration concept. Further tests on real exchange rates indicate that the symmetry and proportionality conditions implied by PPP are rejected in all but one case. The latter tests also show that departures from long-term exchange values can last for several years and that a priori restrictions imposed on the cointegrating vector can lead to a false rejection of the PPP concept.     

Equilibrium exchange rate determination and multiple structural changes

The large appreciation and depreciation of the US Dollar in the 1980s stimulated an important debate on the usefulness of unit root tests in the presence of structural breaks. In this paper, we propose a simple model to describe the evolution of the real exchange rate. We then propose a more general smooth transition (STR) function than has hitherto been employed, which is able to capture structural changes along the (long-run) equilibrium path, and show that this is consistent with our economic model. Our framework allows for a gradual adjustment between regimes and allows for under- and/or over-valued exchange rate adjustments. Using monthly and quarterly data for up to twenty OECD countries, we apply our methodology to investigate the univariate time series properties of CPI-based real exchange rates with both the U.S. Dollar and German Mark as the numeraire currencies. The empirical results show that, for more than half of the quarterly series, the evidence in favor of the stationarity of the real exchange rate was clearer in the sub-sample period post-1980.     

Real exchange rate adjustment in European transition countries

In single-equation tests, real exchange rates show mean reversion for nine of 10 Central and Eastern European transition countries for the period January 1993 to December 2005. Because of the shift from controlled to market economies and accompanying crises, failed policy regimes and changes in exchange rate regimes, unit root tests for transition countries often require allowance for structural changes. Accounting for structural breaks gives substantially faster mean-reversion speeds than those found for major industrialized countries. These fast adjustment speeds are plausible: Transition countries had perhaps 10 years to make unprecedented adjustments required for accession to the European Union. A number of papers have applied non-linear models to the Central and Eastern European countries. This paper investigates four non-linear models and compares them with piece-wise linear break models. The break models appear superior in detecting mean reversion for the Central and Eastern European transition countries.     

Long memory or structural breaks: can either explain nonstationary real exchange rates under the current float?

This paper considers two potential rationales for the apparent absence of mean reversion in real exchange rates in the post-Bretton Woods era. We allow for (i) fractional integration and (ii) a double mean shift in the real exchange rate process. These methods, applied to CPI-based rates for 17 countries and WPI-based rates for 12 countries, demonstrate that the unit-root hypothesis is robust against both fractional alternatives and structural breaks. This evidence suggests rejection of the doctrine of absolute long-run purchasing power parity during the post-Bretton Woods era.     

Random walk versus breaking trend in stock prices: Evidence from emerging markets

This paper investigates whether stock-price indexes of seventeen emerging markets can be characterized as random walk (unit root) or mean reversion processes. We implement a test that can account for structural breaks in the underlying series and is more powerful than standard tests. We find that for fourteen countries, stock prices exhibit structural breaks. Furthermore, for ten countries, the null hypothesis of a random walk can be rejected at the one or 5% significance level. Our results indicate that ignoring structural breaks that arise from the liberalization of emerging markets can lead to incorrect inference that these indices are characterized by random walks, and are consistent with the points made by Bekaert et al. [J. Int. Money Finan. 21 (2002) 295]. Our findings hold true regardless of whether stock indexes are denominated in US dollar terms, in local currencies terms, or in real terms.     

Nonlinear exchange rate predictability

We study whether the nonlinear behavior of the real exchange rate can help us account for the lack of predictability of the nominal exchange rate. We construct a smooth nonlinear error-correction model that allows us to test the hypotheses of nonlinear predictability of the nominal exchange rate and nonlinear behavior on the real exchange rate in the context of a fully specified cointegrated system. Using a panel of 19 countries and three numeraires, we find evidence of nonlinear predictability of the nominal exchange rate and of nonlinear mean reversion of the real exchange rate. Out-of-sample Theil’s U -statistics show a higher forecast precision of the nonlinear model than the one obtained with a random walk specification. Although the robustness of the out-of-sample results over different forecast windows is somewhat limited, we are able to obtain significant predictability gains—from a parsimonious structural model with PPP fundamentals—even at short-run horizons.     

Deviations from purchasing power parity under different exchange rate regimes: Do they revert and,if so,how?

We propose an empirical model for deviations from long-run purchasing power parity (PPP) that simultaneously accounts for three key features: (i) adjustment toward PPP may occur via nominal exchange rates and relative prices at different speeds; (ii) different exchange rate regimes may generate regime shifts in the structural dynamics of PPP deviations; (iii) nonlinear reversion toward PPP in response to shocks. This empirical framework encompasses and synthesizes much previous empirical research. Using over a century of data for the G5 countries, we provide evidence that long-run PPP holds, the relative importance of nominal exchange rates and prices in restoring PPP varies over time and across different exchange rate regimes, and reversion to PPP occurs nonlinearly, at a speed that is fairly consistent with the nominal rigidities suggested by conventional open economy models.     

Do real interest rates converge? Evidence from the European union

We test for real interest rate convergence in the EU25 area. Our contribution is twofold: first, we account for the previously overlooked effects of structural breaks on real interest rate differentials. Second, we test for convergence against the EMU average. For the majority of our sample countries we obtain evidence of convergence towards the latter. This, however, is a gradual process subject to structural breaks, typically falling close to the launch of the euro. Our findings have important implications relating to the single monetary policy and the progress new EU members have achieved towards joining the euro.     

The impact of exchange rate deviations from relative PPP equilibrium on the U.S. demand for foreign equities

Applying fixed-effects panel data, this study investigates the impact of U.S. dollar exchange rate movements during different exchange rate states (overvaluation and undervaluation) on the monthly real gross and real net purchases of foreign equities by U.S. residents over the post-Plaza Accord period. The foreign equities come from 22 developed and 25 developing countries. Previous research has posited two alternative hypotheses regarding the relationship between exchange rates and foreign investment. These are the wealth effect and the profit-oriented effect. The evidence herein suggests that these two hypotheses coexist. We find robust evidence for a negative relationship between the exchange rate movements of an undervalued U.S. dollar and the demand for foreign equities. For developed countries, the wealth effect dominates the profit-oriented effect when the U.S. dollar is overvalued, while, for developing countries, the profit-oriented effect dominates the wealth effect. The results emphasize the importance of considering exchange rate states derived from a relative PPP equilibrium when analyzing U.S. allocations to foreign equities. The findings with respect to the macroeconomic control variables are mainly in agreement with the predictions of international financial theory. Some of the results, however, disappear or become inconclusive for the period after the bankruptcy of Lehman Brothers. This may be explained by the increased uncertainty in international financial markets following this unprecedented event. The findings are robust with respect to different constructed equilibrium exchange rates.     

Mean reversion in long-horizon real exchange rates: Evidence from Latin America

This paper examines mean reversion in real effective exchange rates in six leading Latin American economies during the XXth century using a new data set. A unit-root approach is complemented by an error-correction model including key fundamentals such as terms of trade, trade openness and relative productivities. Unit-root testing shows a very slow process of reversion – if any – to a constant mean in the original series, rejecting the strict PPP hypothesis; however, mean reversion is found after allowing for trends and structural breaks with a half-life average of 1½ years for the six countries. We also found reversion to a conditional mean defined by the co-integrating relationship with an average half-life of 2½ years. Our estimates, although lower than the 3–5 year range that motivated the Rogoff’s puzzle, still indicate the presence of important obstacles to the adjustment process that need further investigation.     

Burgernomics: the economics of the Big Mac standard

In the course of PPP research, much of the debate over the validity has been over the choice of an appropriate ‘basket’ for making purchasing power comparisons. The different compositions of goods and services in these baskets across countries have resulted in arguments against their usefulness for PPP purposes. This problem is augmented by the existence of productivity differentials in traded and non-traded goods across countries. Therefore we consider the use of the Big Mac as the international monetary standard as being a more palatable alternative: It is produced locally in over 80 countries around the world, with only minor changes in recipe and thus has the flavour of ‘the perfect universal commodity’. Our results indicate that the Big Mac Index is surprisingly accurate in tracking exchange rates over the long-term, which is consistent with previous PPP research findings. We subsequently enhance our PPP comparisons by taking into account the productivity differentials between countries and excluding non-traded goods from the Big Mac Index to derive the No-Frills Index.     

Cointegrated Periodically Collapsing Bubbles in the Exchange Rate of “BRICS”

We test the occurrence of periodically recurring rational bubbles in the exchange rate of each of the “BRICS” countries currency relative to the US dollar. The forward exchange rate is used as a proxy for the expected exchange rate, different Purchasing Parity Power (PPP)-based rules for the fundamental exchange rate are considered, and its initial value is endogenously determined. For the chosen model, the regime switching equation satisfactorily fits the data, confirming the presence of rational bubbles for all countries. The dynamics of the exchange rate series for each country is interpreted with the help of the estimated bubbles. The bubbles are compared across countries, found to be cointegrated, and this is interpreted as evidence of the international transmission of exchange rate shocks between these countries.     

Local persistence and the PPP hypothesis

This paper examines the statistical properties of the bilateral real exchange rates of the U.S. vs. France, Germany, and the U.K. during the Post-Bretton-Woods period, and draws implications on the Purchasing Power Parity (PPP) hypothesis. Contrary to traditional studies that consider only unit root and stationary processes to describe the real exchange rate behavior, this paper considers an in-between process, the locally persistent process. The empirical results demonstrate the following two findings: (1) Locally persistent processes describe the real exchange rate movements better than unit root and stationary processes, which implies that PPP reversion occurs and PPP holds in the long-run. (2) The confidence intervals for half-life deviations from PPP under local persistence tend to be narrower than those obtained by assuming the ADF and the local-to-unity models.     

A century of purchasing power parity confirmed: The role of nonlinearity

Taylor (2002) claims that Purchasing Power Parity (PPP) has held over the 20th century based on strong evidence of stationary for century-long real exchange rates for 20 countries. Lopez et al. (2005), however, found much weaker evidence of PPP with alternative lag selection methods. We reevaluate Taylor’s claim by implementing a recently developed nonlinear unit root test by Park and Shintani (2005). We find strong evidence of nonlinear mean-reversion in real exchange rates that confirms Taylor’s claim. We also find a possible misspecification problem in using the ESTAR model that may not be detected with Taylor-approximation based tests.