Trade concentration, openness, and deviations from purchasing power parity

Economists have often explained deviations from PPP in terms of random relative price changes. While all countries are subject to such real shock, empirical studies indicate that PPP seems to hold closer for some countries than others. This paper emphasizes two major reasons why we should expect systematic differences across countries in deviations from PPP: (a) the concentration of trade and (b) openness. The more diversified trade, the less susceptible the country to random shocks affecting individual goods, so that shifts in the PPP ratio are lower. The more open the economy, the greater the weight of traded goods in the overall price indices, so that if exchange rates are determined by traded goods prices, yet empirical tests of PPP use national price indices, PPP should hold better in more open economies.     

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.     

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.     

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.     

Testing for long-run PPP in a system context: Evidence for the US,Germany and Japan

This paper extends the current literature on PPP by re-examining the validity of the PPP hypothesis for the three key currencies of the recent floating exchange rate period, in a multilateral framework. We argue that PPP testing is more adequate in a system context, which takes into account the dynamic interactions of exchange rates and prices of more than two economies, simultaneously. In the system analysis framework, some form of causality among the variables under consideration is also assessed empirically with the aid of weak exogeneity tests. The results illustrate the importance of the multilateral testing. Positive evidence for PPP is found: long-run PPP is supported for the US and Germany but also for the US and Japan, in contrast to evidence of earlier empirical studies. In addition, causality is found running from the US prices to the exchange rates and German and Japanese prices.     

Nominal exchange rate volatility,relative price volatility,and the real exchange rate

We model real exchange rate, nominal exchange rate, and relative price volatility using real and nominal factors. We analyze these volatility measures across developing and industrialized countries. We find that the inclusion of nominal factors achieves a sizable reduction in the real exchange rate volatility spread between developing and industrialized countries. In addition, we find that nominal factors matter to real exchange rate volatility in the short run and the long run, and that for developing countries, a higher share of real exchange rate volatility stems from relative price volatility.     

Price level convergence and regional Phillips curves in the US and EMU

We use panel estimates of regional Phillips curves of the hybrid New Keynesian type to study price level convergence within the US and EMU. Regional inflation rates tend to eliminate PPP deviations in both monetary unions, with average half-lives around 3½ years. The start of EMU did not greatly affect PPP reversion in the euro area. Where changes in nominal exchange rates accounted for the bulk of the adjustment process before 1999, this role was largely taken over by regional inflation differences since. Notwithstanding clear evidence of forward-lookingness in the US, inflation persistence is substantial in both monetary unions.     

Emerging floaters: Pass-throughs and (some) new commodity currencies

In spite of early skepticism on the merits of floating exchange rate regimes in emerging markets, 8 of the 25 largest countries in this group have now had a floating exchange rate regime for more than a decade. Using parsimonious VAR specifications covering the period of floating exchange rates, this study computes the dynamics of exchange rate pass-throughs to consumer price indices. We find that pass-throughs have typically been moderate even though emerging floaters have seen considerable nominal and real exchange rate volatilities. Previous studies that set out to estimate exchange rate pass-throughs ignored changes in policy regimes, making them vulnerable to the Lucas critique. We find that, within the group of emerging floaters, estimated pass-throughs are higher for countries with greater nominal exchange rate volatilities and that trade more homogeneous goods. These findings are consistent with the pass-through model of Floden and Wilander (2006) and earlier findings by Campa and Goldberg (2005), respectively. Furthermore, we find that the Indonesian Rupiah, the Thai Baht and possibly the Mexican Peso are commodity currencies, in the sense that their real exchange rates are cointegrated with international commodity prices.     

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.     

The Long‐Run Fisher Effect: Can It Be Tested?

In this paper, I provide a plausible explanation as to why past studies have been unable to find support for the long-run Fisher effect. My argument is that exogenous shocks to the inflation rates in industrialized economies have not produced the permanent change to inflation necessary for testing the Fisher effect. Instead of finding a nonstationary, unit-root process for inflation like previous Fisher effect studies, here each country's inflation rate is found to follow a mean-reverting, fractionally integrated, long-memory process. Applying a bivariate, maximum likelihood estimator to a multivariate, fractionally integrated model of inflation and nominal interest, I find that the estimated inflation rates in 17 developed countries are highly persistent, fractionally integrated, mean-reverting processes with order of integration parameters significantly less than one. Since a permanent change to inflation has not occurred, a test of whether a permanent change to inflation affects the nominal interest rate one-for-one will be uninformative as to the truth or fallacy of the Fisher effect hypothesis.     

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.     

A re-examination on dissecting the purchasing power parity puzzle

The purpose of this paper is to examine the source of a real exchange-rate adjustment based on the impulse-response function constructed from local projections when the true data-generating process (DGP) is unknown. This work extends the local-projection method proposed by Jordà [2005. Estimation and inference of impulse responses by local projections. American Economic Review 95, 161-182] to allow for variables that are I(1) and exhibit cointegration. Our paper shows that nominal exchange-rate adjustments dominate in the reversion toward PPP regardless of a nominal exchange-rate shock or a price shock. It is also shown that the half-life of real exchange rates is close to that of nominal exchange rates. Since these results are consistent with those of Cheung et al. [Cheung, Y.W., Lai, K.S., Bergman, M., 2004. Dissecting the PPP puzzle: the unconventional roles of nominal exchange rate and price adjustments. Journal of International Economics 64, 135-150], we therefore conclude that their main findings are robust to possible misspecifications in the true DGP.     

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.     

The forward rate unbiasedness hypothesis reexamined: evidence from a new test

Under conditions of risk neutrality and rational expectations in the foreign exchange market, there should be a one-to-one relationship between the forward rate and the corresponding future spot rate. However, cointegration-based tests of the unbiasedness hypothesis of the forward rate have produced mixed findings. In order to exploit significant cross-sectional dependencies, we test the unbiasedness hypothesis using a new multivariate (panel) unit-root test, the Johansen likelihood ratio (JLR) test, which offers important methodological advantages over alternative standard panel unit-root tests. When applied to a data set of eight major currencies in the post-Bretton Woods era, the JLR test provides strong and robust evidence in support of a unitary cointegrating vector between forward and corresponding future spot rates. However, the orthogonality condition is satisfied only for three major currencies.     

Real Rates, Expected Inflation, and Inflation Risk Premia

This paper studies the term structure of real rates, expected inflation, and inflation risk premia. The analysis is based on new estimates of the real term structure derived from the prices of index-linked and nominal debt in the U.K. I find strong evidence to reject both the Fisher Hypothesis and versions of the Expectations Hypothesis for real rates. The estimates also imply the presence of time-varying inflation risk premia throughout the term structure.     

Real exchange rates under alternative nominal exchange-rate systems

The paper develops an equilibrium model of the determination of exchange rates, the relative price of nontraded goods, and the current account. The focus is on the effects of various real and nominal disturbances and the conditions under which the nominal exchange-rate system is neutral with respect to real variables in the economy. The model demonstrates an assymetry in the roles of trade and nontraded goods in affecting exchange rates. An econometric investigation of the raltion between the exchange-rate system and the variability of real exchange rates provides some evidence against the neutrality hypothesis.     

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。