Purchasing Power Parity in Three Transition Economies

This paper uses cointegration analysis on monthly data over April 1994-December 2000 to test the relevance theory of Purchasing Power Parity (PPP) for two advanced transition economies (Poland and the Czech Republic) and one lagging transition economy (Romania). PPP is not rejected between the lagging reformer and developed market economies, but is rejected between the advanced reformers and the developed economies. However, PPP is not rejected between the two advanced transition economies, though it is rejected between the lagging and advanced transition economies. The evolution of the real exchange rates over 1994-2000 suggest that a significant explanation for these findings is the central role of the exchange rate in the disinflation strategies of Poland and the Czech Republic in the early part of this period, in contrast to the managed float followed by Romania throughout the period.     

Nonlinear adjustment,purchasing power parity and the role of nominal exchange rates and prices

Although the literature on purchasing power parity (PPP) is rich in controversy, the relative contribution of prices and nominal exchange rates to real exchange rate movements which restore PPP disequilibria has rarely been put under any close scrutiny. This paper as a first step applies a cointegrated VAR framework to test for stationary real exchange rates and linear adjustments in prices and nominal exchange rates. As a second step, ESTR error correction models are fitted to test whether nonlinear error correctional behaviour characterizes the data. The results clearly indicate that the nominal exchange rate is responsible for the nonlinear mean reverting behaviour in real exchange rates and also mainly drives overall adjustment. Applying dynamic stochastic simulations based on the estimated models, this study also confirms recent results that the half-life times of real exchange rate shocks are significantly smaller than the consensus benchmark of 3–5 years.     

The Yen Real Exchange Rate may be Stationary after all: Evidence from Non‐linear Unit‐root Tests*

The empirical literature that tests for purchasing power parity (PPP) by focusing on the stationarity of real exchange rates has so far provided, at best, mixed results. The behaviour of the yen real exchange rate has most stubbornly challenged the PPP hypothesis and deepened this puzzle. This paper contributes to this discussion by providing new evidence on the stationarity of bilateral yen real exchange rates. We employ a non‐linear version of the augmented Dickey–Fuller test, based on an exponentially smooth‐transition autoregressive model (ESTAR) that enhances the power of the tests against mean‐reverting non‐linear alternative hypotheses. Our results suggest that the bilateral yen real exchange rates against the other G7 and Asian currencies were mean reverting during the post‐Bretton Woods era. Thus, the real yen behaviour may not be so different after all but simply perceived to be so because of the use of a restrictive alternative hypothesis in previous tests.     

Further Evidence on PPP Adjustment Speeds: the Case of Effective Real Exchange Rates and the EMS*

Two different approaches intend to resolve the ‘puzzling’ slow convergence to purchasing power parity (PPP) reported in the literature [see Rogoff (1996) , Journal of Economic Literature, Vol. 34.] On the one hand, there are models that consider a non‐linear adjustment of real exchange rate to PPP induced by transaction costs. Such costs imply the presence of a certain transaction band where adjustment is too costly to be undertaken. On the other hand, there are models that relax the ‘classical’ PPP assumption of constant equilibrium real exchange rates. A prominent theory put together by Balassa (1964, Journal of Political Economy, Vol. 72) and Samuelson (1964 Review of Economics and Statistics, Vol. 46) , the BS effect, suggests that a non‐constant real exchange rate equilibrium is induced by different productivity growth rates between countries. This paper reconciles those two approaches by considering an exponential smooth transition‐in‐deviation non‐linear adjustment mechanism towards non‐constant equilibrium real exchange rates within the EMS (European Monetary System) and effective rates. The equilibrium is proxied, in a theoretically appealing manner, using deterministic trends and the relative price of non‐tradables to proxy for BS effects. The empirical results provide further support for the hypothesis that real exchange rates are well described by symmetric, nonlinear processes. Furthermore, the half‐life of shocks in such models is found to be dramatically shorter than that obtained in linear models.     

Real exchange rate behaviour: evidence from black markets

The behaviour of real exchange rates (relative to the US dollar) is examined using monthly data obtained from the black markets for foreign exchange of eight Asian developing countries. The data span is 31 years. The black market real exchange rates do not show excess volatility during the recent float which is in sharp contrast to the results reported elsewhere. Unit root tests in heterogeneous panels and variance ratio tests confirm their stationarity. Thus, we find support for PPP but not for the ‘survivorship’ bias (Froot and Rogoff, 1995 ). There is little evidence of segmented trends. Issues raised by Rogoff ( 1996 )—of whether PPP would hold across countries with differing growth experience—and Lothian and Taylor ( 1996 )—of whether the degree of relative price volatility may bias results in favour of mean reverting real exchange rates—are addressed. Copyright © 2000 John Wiley & Sons, Ltd.     

On the Empirical Failure of Purchasing Power Parity Tests

Empirical research on the validity of the purchasing power parity (PPP) condition is generally based on real exchange rates built using the consumer price index (CPI), but fails to provide clear support to PPP. In this paper we show theoretically that, even if the law of one price (LOP) holds for traded goods, CPI‐based real exchange rates are not mean reverting, and are neither stationary nor integrated. Therefore, both unit root and stationarity tests should reject their null. Our theoretical results are validated both by simulations and an empirical application. Copyright © 2014 John Wiley & Sons, Ltd.     

PURCHASING POWER PARITY FOR DEVELOPING AND DEVELOPED COUNTRIES. WHAT CAN WE LEARN FROM NON‐STATIONARY PANEL DATA MODELS?

Abstract.  The aim of this paper is to apply recently developed panel cointegration techniques proposed by Pedroni ( Oxford Bulletin of Economics and Statistics 61 (1999): Supplement, 653–670; Econometric Theory 20 (2004): 597–625) and generalized by Banerjee and Carrion-i-Silvestre (Working Paper 591, European Central Bank, February 2006) to examine the robustness of the PPP concept for a sample of 80 developed and developing countries. We find that strong PPP is verified for OECD countries and weak PPP for Middle East and North African countries. However, in African, Asian, Latin American and Central and Eastern European countries, PPP does not seem relevant to characterize the long-run behavior of the real exchange rate. Further investigations indicate that the nature of the exchange rate regime does not condition the validity of PPP, which is more easily accepted in countries with high rather than low inflation.     

Is PPP sensitive to time-varying trade weights in constructing real effective exchange rates?

While the use of real effective exchange rates in stationarity tests of purchasing power parity (PPP) avoids the problems created using bilateral rates, these rates are often constructed using trade shares that are fixed at a single base year. This method fails to take into account the fact that trade shares can change drastically in parts of the world that are undergoing dramatic transformations. In this study, we apply linear as well as nonlinear stationarity tests to 52 currencies’ real effective rates, which were constructed using time-varying weights. Incorporating a time trend, we are also able to assess whether breakdowns in PPP are due to productivity differentials. We find that while nonlinear tests provide more evidence of “productivity bias” than do linear tests, they do not provide much more evidence of PPP. A comparison to a previous study that used fixed-weight data shows that there is somewhat more evidence of productivity bias using the new dataset, especially in Eastern Europe and Asia. We can conclude that PPP and a key cause of its breakdown are somewhat sensitive to the use of time-varying weights in these stationarity tests.     

Evidence on purchasing power parity from univariate models: the case of smooth transition trend‐stationarity

Recent research has found that trend‐break unit root tests derived from univariate linear models do not support the hypothesis of long‐run purchasing power parity (PPP) for US dollar real exchange rates. In this paper univariate smooth transition models are utilized to develop unit root tests that allow under the alternative hypothesis for stationarity around a gradually changing deterministic trend function. These tests reveal statistically significant evidence against the null hypothesis of a unit root for the real exchange rates of a number of countries against the US dollar. However, restrictions consistent with long‐run PPP are rejected for some of the countries for which a rejection of the unit root hypothesis is obtained. Copyright © 2005 John Wiley & Sons, Ltd.     

Real exchange rate,stationarity, and economic fundamentals

Using monthly data for the US/UK real exchange rate over the period 1921–2002, we find evidence that the mean reverting tendency of the real exchange rate is stochastic, and regime-dependent. There is one regime over which PPP holds as a long-run equilibrium relation, i.e. a stationary PPP regime, and another regime over which PPP does not hold, i.e. a non-stationary PPP regime. The transition from the non-stationary to the stationary regime is found to be affected by the real interest rate differential, and by the volatility of the nominal exchange rate. The real output differential does not appear to affect the transition probability.     

Long-run dynamics of exchange rates: A multi-frequency investigation

The empirical observation that purchasing power parity (PPP) holds in the long run but not in the short run has enjoyed a near-consensus status in international finance literature. However, a similar degree of agreement has not been reached with respect to the exact horizon of this “long run” aspect. To shed light on this matter, a novel approach is adopted in this paper to combine conventional time series methodology with insights from multi-frequency analyses. In particular, we simultaneously explore price-exchange-rate dynamics not only through time, but also at various horizons via a wavelet decomposition. Unit root tests applied to wavelet-based decomposed real exchange rates indicates that PPP holds at horizons consistent with the literature. With respect to the predictive value of our approach, we show that our decomposed measures provide guidance to future movements of real change rates. Additionally, we find that nominal exchange-rate dynamics are dominated by activities corresponding to low frequencies. Results from this study thus enable researchers and practitioners to establish an exchange-rate modelling framework with increased efficiency.     

Testing the purchasing power parity through I(2) cointegration techniques

This paper contributes to the empirical literature on the purchasing power parity (PPP) over the post‐Bretton Woods period by providing a time‐series based interpretation of the controversial evidence characterizing the dynamics of real exchange rates. It is shown that the persistence of deviations from the PPP between a set of European countries and the United States may be empirically attributed to the presence of I(2) stochastic trends in prices using Consumer Price Indices. Interestingly, the slow adjustment towards the equilibrium can be modelled through ‘integral‐proportional’ equilibrium correction models and this evidence can be partly reconciled with theories where the inflation rate reduces the markup of profit‐maximizing firms acting on imperfectly competitive markets. Copyright © 2005 John Wiley & Sons, Ltd.     

HOW PUZZLING IS THE PPP PUZZLE? AN ALTERNATIVE HALF‐LIFE MEASURE OF CONVERGENCE TO PPP

Evidence of lengthy half‐lives for real exchange rates in the presence of a high degree of exchange rate volatility has been considered as one of the most puzzling empirical regularities in international macroeconomics. This paper suggests that the measure of half‐life used in the literature might be problematic and proposes alternative measures with desirable properties. Their focus on the cumulative effects of the shocks distinguishes them from the measures used in the literature. An empirical analysis of bilateral US dollar real exchange rates employing the alternative half‐life measure produces results consistent with theory and indicates that the PPP puzzle is less pronounced than initially thought. Copyright © 2012 John Wiley & Sons, Ltd.     

Purchasing power parity as a long-run relation

Dickey–Fuller and Stock–Watson tests of purchasing power parity (PPP) as a long-run proposition are provided within the cointegration framework proposed by Granger. Since different countries use different weights to construct price indices, the traditional constraint that the coefficients on the price indices should be unity in the log-linear PPP relation is relaxed. The absence of a general PPP relation cannot be rejected. At most, a PPP relation is indicated in five out of fifteen country pairs that are examined. Even if a long-run PPP relation exists, it is not found to be useful in predicting future nominal exchange rates, which is consistent with efficient speculative markets.     

Bond market co-movements,expected inflation and the GBP-USD equilibrium real exchange rate

Since the end of the fixed rates in 1973 and after the European Monetary System (EMS) sterling dismissal in 1992, the value of the pound has undergone large cyclical fluctuations on average. Of particular interest to policy makers is the understanding of whether such movements are consistent with the lack or not of a correction mechanism to some long-run equilibrium. The purpose of the present study is to understand those dynamics, how the external value of the British sterling (GBP) relative to the US dollar (USD) evolved during the recent floating experiences, and what have been the driving forces. In this paper we assume the real exchange rate to be determined by forces relating to the goods and capital market in a general equilibrium framework. This entails testing the purchasing power parity (PPP) and the uncovered interest parity (UIP) together. In doing so, we model inflation expectations explicitly. Our findings have two important implications, both for monetary policy. First, we show that some of the observed changes in the bilateral real exchange rate cannot be solely attributed to changes in inflation rates, but, also to capital markets. Secondly, we find a weaker behavior of the US bond rate on international markets, possibly explained by the special US dollar status of World reserve currency.     

Temporal aggregation of an ESTAR process: some implications for purchasing power parity adjustment

Nonlinear models of deviations from PPP have recently provided an important, theoretically well motivated, contribution to the PPP puzzle. Most of these studies use temporally aggregated data to empirically estimate the nonlinear models. As noted by Taylor ( 2001 ), if the true DGP is nonlinear, the temporally aggregated data could exhibit misleading properties regarding the adjustment speeds. We examine the effects of different levels of temporal aggregation on estimates of ESTAR models of real exchange rates. Copyright © 2006 John Wiley & Sons, Ltd.     

Disaggregate productivity comparisons: sectoral convergence in OECD countries

International comparisons of productivity have used exchange rates or purchasing power parity (PPP) to make output comparable across countries. While aggregate PPP holds well in the long run, sectoral deviations are persistent. It raises the need for a currency conversion factor at the same level of aggregation as the output that is compared. Mapping prices from household expenditure surveys into the industrial classification of sectors and adjusting for taxes and international trade, I obtain an expenditure-based sector-specific PPP. Using detailed price data for up to 8 years between 1970 and 1999, I test whether the sectoral PPPs adequately capture differential changes in relative prices between countries. They work well for agriculture and the majority of industrial sectors, but not for most service sectors and for manufacturing sectors that produce differentiated products. Using the most appropriate conversion factor for each industry, productivity convergence is found to be taking place in all but a few industries for a group of 14 OECD countries. The latter results are robust to the base year used for the currency conversion.     

人民币汇率购买力平价的实证检验——基于中国加入SDR后的视角

2005年7月开始的人民币汇率形成机制改革使人民币均衡汇率的确定逐渐具有了市场基础。2015年11月人民币加入SOR对我国汇率市场化程度提出了新要求。在这种背景下，使用2005—2015年数据测算购买力平价理论在我国人民币与其他国家货币双边汇率决定中的有效性，同时测算对购买力平价偏离的半衰期，结果表明：人民币与印度卢比、韩元和南非兰特的双边汇率支持弱购买力平价成立，但半衰期存在差别；强购买力平价没有得到支持。     

An examination of the forward prediction error of U.S. dollar exchange rates and how they are related to bid-ask spreads,purchasing power parity disequilibria,and forward premium asymmetry

Using a panel data approach, we find statistically significant evidence that bid-ask spreads and deviations from purchasing power parity (PPP) are related to the forward prediction error of ten major U.S. dollar exchange rates over the post Plaza Accord period. Previous literature suggests that bid-ask spreads proxy for liquidity risk and deviations from PPP are a source of time-varying risk premiums. Additionally, the paper provides evidence that the forward discount bias is asymmetric with respect to the sign of the forward premium as well as to an undervalued and overvalued U.S. dollar.     

Real exchange rate persistence and the excess return puzzle: The case of Switzerland versus the US

The PPP puzzle refers to the wide swings of nominal exchange rates around their long‐run equilibrium values whereas the excess return puzzle represents the persistent deviation of the domestic‐foreign interest rate differential from the expected change in the nominal exchange rate. Using the I(2) cointegrated VAR model, much of the excess return puzzle disappears when an uncertainty premium in the foreign exchange market, proxied by the persistent PPP gap, is introduced. Self‐reinforcing feedback mechanisms seem to cause the persistence in the Swiss‐US parity conditions. These results support imperfect knowledge based expectations rather than so‐called “rational expectations”.