Testing the Purchasing Power Parity Hypothesis for the New Member and Candidate Countries of the European Union: Evidence from Lagrange Multiplier Unit Root Tests with Structural Breaks

This paper investigates the validity of purchasing power parity (PPP) for the eleven Central and East European transition countries and three market economy countries, Cyprus, Malta, and Turkey. Unlike previous studies on PPP, this study uses Lagrange multiplier (LM) unit root tests that incorporate structural breaks in the data series. The findings indicate that in cases of one and two structural breaks, for a U.S. dollar-based real exchange rate series, there is little evidence supporting the validity of PPP. For a deutsche mark-based real exchange rate series, for the cases of both one and two breaks, there is evidence of stationarity of real exchange rates for eight sample countries, which is consistent with PPP. The results also indicate that the estimated half-life of a shock to the real exchange rate ranges from 1.25 (15.05 months) to 2.72 (32.72 months) years across countries. The empirical findings may provide direction for policy makers to coordinate monetary policies for the process of European monetary integration.     

Long-run PPP in a system context: No favorable evidence after all for the U.S., Germany, and Japan

In a cointegration analysis of PPP in five-variable system for Germany, Japan, and the U.S., Sideris [Sideris, D., 2006. Testing for long-run PPP in a system context: evidence for the U.S., Germany and Japan. Journal of International Financial Markets, Institutions and Money 16, 143–154] reports three cointegration vectors and concludes that they are consistent with some form of PPP for all three exchange rates. The present paper reconsiders Sideris's three-country analysis with special attention to the specification of deterministic terms in the cointegration testing. In addition, the passage of time since the Sideris paper allows the data set to be extended. The present paper also applies the Johansen approach and longer data set to traditional two-country models for the same exchange rates. In no case is any evidence in favor of PPP found.     

Purchasing power parity, unit roots, and dynamic structure

Recent studies of purchasing power parity (PPP) account for the possible presence of unit roots in nominal exchange rates and relative price indices by applying standard unit-root tests to real exchange rates, which are ratios of nominal exchange rates and relative price indices. These studies occasionally find evidence of PPP, but as a whole, the evidence is not definitive. Standard unit-root tests impose a restrictive dynamic structure between nominal exchange rates and relative price indices. I specify and estimate a generalized dynamic structure. I reject the dynamic restrictions implicit in standard unit-root tests of PPP, and find stronger evidence of PPP than do most other recent studies.     

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.     

人民币购买力平价成立吗?——基于人民币兑欧元的多样本协整分析

选取人民币兑非主权国家货币——欧元的名义汇率,中国CPI指数及欧元区调和HICP指数的数据,以欧元正式成为欧元区唯一合法货币的起点2002年7月到2018年12月为样本,依据影响中欧汇率的重要节点事件对样本进行分段与结合,对人民币兑欧元购买力平价(PPP)成立与否进行协整检验。实证结论有:人民币汇率形成制度改革及欧元平稳运行后的(2005年8月—2018年12月)人民币兑欧元购买力平价协整检验成立;非主权国家货币欧元同样适用经典的购买力平价理论;2008年金融危机是影响汇率市场的重要节点事件,但长期不影响人民币兑欧元购买力平价成立;对PPP冲击影响最大的首先是汇率本身,其次依次是欧元区HICP、中国CPI。因此,购买力平价在一定程度上能够解释人民币兑欧元汇率,对中欧经贸往来有一定的指导作用。     

The Roles of Nominal Exchange Rate and Relative Price Adjustments in PPP Reversion

This paper investigates the roles of the nominal exchange rate and relative prices in restoring purchasing power parity (PPP) by estimating their dynamics with a bivariate threshold vector error correction model. Our empirical results suggest a threshold cointegrating relationship between the nominal exchange rate and relative prices. However, these two variables play different roles in restoring PPP. The nominal exchange rate adjusts to restore PPP only outside the threshold band. Within the band, PPP is restored mainly through adjustments in relative prices.     

Purchasing power parity: Modeling and testing mean reversion

A model of mean reversion of exchange rates to purchasing power parity is developed and tested where exchange rates are assumed to follow a mean reverting elastic random walk toward a stochastic PPP rate. The model recognizes the possibility that mean reversion towards PPP may be nonlinear which allows greater flexibility in the adjustment process. Regression equations consistent with the theoretical model are derived. The model is tested using long- and short-term data for six countries. While the results are generally consistent with the findings of previous studies, evidence is presented which demonstrates that the mean reversion process is not linear for some countries.     

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.     

Post Bretton Woods deviations from purchasing power parity in G7 exchange rates—an empirical exploration

Exchange rates have deviated substantially and idiosyncratically from purchasing power parity (PPP) since the breakdown of Bretton Woods. In this paper, a model incorporating both traditional PPP and financial market variables is constructed and tested on the US dollar's six G7 exchange rates during the floating rate era. Empirical tests show that the model's common set of variables—with consistent signs—can explain the divergent behavior of G7 exchange rates during 1973.2–90.2. Idiosyncracies are reflected in different subsets of the model's variables entering significantly into each exchange rate's regression; the existence of stable relationships is demonstrated by the equations' co-integration.     

Natural Exchange Rate and Its Implications for the Purchasing Power Parity Puzzle

The notion of purchasing power parity has been an important building block in the theory of nominal and real exchange rates and for many theoretic models in international economics, leading to the purchasing power parity puzzle. The central issue of the puzzle is how to reconcile volatile short-term movements of real exchange rates (defined as nominal exchange rates adjusted for differences in national price levels) with very slow convergence to the parity condition. The main emphasis of this article is to show that the slow adjustment of the natural exchange rate is responsible for the well-known slow convergence of the real exchange rate to the long-run parity condition. The novel element of this article is to identify the relative importance between the financial channel and output gap channel of the purchasing power parity puzzle. The empirical findings of this article suggest that the financial channel is a dominant factor to explain persistent deviations of the real exchange rate from its long-run level.     

The Exchange Rate in the Presence of Transaction Costs: Implications for Tests of Purchasing Power Parity

With transaction costs for trading goods, the nominal exchange rate moves within a band around the nominal purchasing power parity (PPP) value. We model the behavior of the band and of the exchange rate within the band. The model explains why there are below-unity slope coefficients in regression tests of PPP, and why these increase toward unity under hyperinflation or with low-frequency data. Our results are independent of the presence of nontraded goods in the economy.     

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.     

Interest Rates and Exchange Rate Movements: Analyzing Short-term Investments in Long-term Bonds

Tests of the uncovered interest rate parity (UIP) are subject to various data problems when long-term interest rates are applied: due to the long investment period, time intervals for measuring exchange rate movements are usually overlapping and therefore not independent. This shortfall can be prevented by considering short-term investments in long-term bonds instead of investments to maturity. This article analyzes the explanatory power of long-term interest rates with regard to 1- and 3-month exchange rate movements by relating return differences from 1- and 3-month investments in domestic and foreign 10-year government bonds to nine different exchange rates. From a Swiss perspective, there is only weak support for an interrelation between return differences and the corresponding exchange rate movements, whereas from a US perspective, the resulting estimates are much more in line with UIP.The reader may for instance consider Engel (1996) and Froot and Thaler (1990).     

Temporal aggregation and purchasing power parity persistence

This paper uses a unique new monthly US-UK real exchange rate series for the January 1794-December 2009 period to reexamine the academic debate over purchasing power parity (PPP). The consensus view described by Rogoff (1996) is that PPP holds in the long-run, but short-run deviations are very persistent, with half-lives ranging from 3 to 5 years. Most of the literature using long time series relies on the annual data developed by Lee (1976) and Lothian and Taylor (1996), which were both constructed from underlying higher-frequency data sources. Estimates of purchasing power parity persistence using these series may therefore be subject to temporal aggregation bias. We find evidence of aggregation bias which indicates the half-life of PPP deviations has been overestimated in much of the previous literature. We also find that estimates of the half-lives are further reduced once we account for the Harrod (1933)-Balassa (1964)-Samuelson (1964) effect. The result of aggregation bias appears to be robust even when considering the case that real exchange rates exhibit nonlinear dynamics.     

A sequential purchasing power parity test for panels of large cross-sections and implications for investors

In this paper we use monthly time series data for not less than 64 countries and a new sequential approach to test for purchasing power parity (PPP). The results are strong in that the evidence in favor of PPP is very weak. In fact, for the US-dollar-based exchange rates the evidence is basically non-existent. In order to eliminate the effect of the base currency, we also apply the sequential PPP test to all pairs of exchange rates, and find similarly weak evidence of PPP. However, for those rates where evidence is found, using a technical trading rule, we find evidence of significant profits. The predictability of the stationary pairs is therefore important for investors.     

Is the relationship between prices and exchange rates homogeneous?

Empirical tests of purchasing power parity (PPP) are implicitly based on the conditions of symmetry and proportionality of the price coefficients. We investigate a separate condition, which we term homogeneity. Specifically, while there may be factors that drive a wedge between prices and exchange rates, when these factors are held constant we would expect a change in exchange rates to be associated with a proportional, or homogeneous, change in prices. To test for the existence of homogeneity in prices, we conduct two experiments. First, we apply a time-varying-coefficient procedure to nine euro-area countries as well as the euro area as a whole during the (monthly) sample period, 1999:M1 to 2011:M3. Second we apply the same procedure to the same group of countries, plus Canada, Japan and Mexico, over the longer period, 1957:M4 to 2011:M3. We find that averages of the price coefficients, corrected for specification biases, are uniformly homogeneous in the long run, providing strong support for PPP.     

人民币汇率的巴拉萨-萨缪尔森效应——基于弹性价格货币模型的分析

本文在汇率的弹性价格货币模型基础上,加入非贸易品与贸易品价格差异因素进行扩展,运用OLS回归方法分析了产出、货币供给、利率对1994-2005年人民币对美元汇率的影响。分析表明,弹性价格货币模型较好的解释了影响人民币对美元汇率的各个因素。贸易品非贸易品的价差显著影响着货币模型的购买力平价和名义汇率的偏离,但是BS效应并不存在。主要原因是作为政策手段的人民币汇率一直被低估,名义汇率低于贸易品购买力平价。     

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.     

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.     

Differential risk premiums and the UIP puzzle

We respecify the uncovered interest rate parity (UIP) conditions by inverting the market price of the risk (Sharpe ratio) formula. Our empirical model provides new insight indicating that violations to the UIP stem from the existence of a risk premium in the exchange rates and from observed market return differentials being a noisy statistic of the markets’ expected return differentials in our respecified model. Using an integrated macro‐micro structure framework for expected market return differentials improves our model fit and the validity of UIP.