Testing Purchasing Power Parity Research Articles

Asymmetry dynamics in real exchange rates: New results on East Asian currencies

This paper provides new evidence on the purchasing power parity (PPP) hypothesis in six East Asian countries. Based on nonlinear unit root tests, we discovered that the results are broadly consistent with the fact that real exchange rates (RERs) follow a nonlinear mean reversion process. We presented new evidence that the adjustment towards the PPP parity is asymmetric (LSTAR process) above and below the equilibrium value in all but one case — the Malaysian ringgit (MYR). The empirical results suggest that it is important that the conventional tests of PPP be amended to take account of asymmetries in the adjustment process in RERs.

Are PPP tests erratically behaved? Some panel evidence

This paper examines whether, in addition to standard unit root and cointegration tests, panel approaches also produce test statistics behaving erratically when applied to tests for Purchasing Power Parity (PPP). We show that if appropriate tests (which are robust to cross‐sectional dependence) are used, any evidence of erratic behaviour disappears, and empirical support is found for PPP.

Why Panel Tests of Purchasing Power Parity Should Allow for Heterogeneous Mean Reversion

Recent studies of purchasing power parity (PPP) use panel tests that fail to take into account heterogeneity in the speed of mean reversion across real exchange rates. In contrast to several other severe restrictions of panel models and tests of PPP, the assumption of homogeneous mean reversion is still widely used and its consequences are virtually unexplored. This paper analyzes the properties of homogeneous and heterogeneous panel unit root testing methodologies. Using Monte Carlo simulation, we uncover important adverse properties of the panel approach that relies on homogeneous estimation and testing. More specifically, power functions are low and assume irregular shapes. Furthermore, homogeneous estimates of the mean reversion parameters exhibit potentially large biases. These properties can lead to misleading inferences on the validity of PPP. Our findings highlight the importance of allowing for heterogeneous estimation when testing for a unit root in panels of real exchange rates.

Pairwise Tests of Purchasing Power Parity

Given nominal exchange rates and price data on N + 1 countries indexed by i = 0,1,2,…, N, the standard procedure for testing purchasing power parity (PPP) is to apply unit root or stationarity tests to N real exchange rates all measured relative to a base country, 0, often taken to be the U.S. Such a procedure is sensitive to the choice of base country, ignores the information in all the other cross-rates and is subject to a high degree of cross-section dependence which has adverse effects on estimation and inference. In this article, we conduct a variety of unit root tests on all possible N(N + 1)/2 real rates between pairs of the N + 1 countries and estimate the proportion of the pairs that are stationary. This proportion can be consistently estimated even in the presence of cross-section dependence. We estimate this proportion using quarterly data on the real exchange rate for 50 countries over the period 1957–2001. The main substantive conclusion is that to reject the null of no adjustment to PPP requires sufficiently large disequilibria to move the real rate out of the band of inaction set by trade costs. In such cases, one can reject the null of no adjustment to PPP up to 90% of the time as compared to around 40% in the whole sample using a linear alternative and almost 60% using a nonlinear alternative.

Non-normality, heteroscedasticity and recursive unit root tests of PPP: solving the PPP puzzle?

In this article, we carry out unit root tests on real exchange rates recursively as in Caporale et al. (2003), but, following Arghyrou and Gregoriou (2007), we adjust the residuals for non-normality and heteroscedasticity using a wild bootstrap method. The results are striking: this correction sharply increases the rejection percentages of the unit root null and attenuates the erratic behaviour of the t-statistic, providing evidence in favour of purchasing power parity (PPP) and suggesting that such a correction might at least go some way towards solving the ‘PPP puzzle’.

Testing Purchasing Power Parity for the New EU Members and Turkey: A Panel Cointegration Analysis with Disaggregated CPI

This study applies multivariate panel cointegration technique to evaluate purchasing power parity (PPP) hypothesis by using consumer price sub-indices of new EU member transition economies and Turkey. We aim not only to compare the parameter estimates across the sectors of an economy but also across the economies at different EU transition stages. We find that failure to get evidence for cointegration to support PPP can be attributed to the inclusion of non-tradable goods in the aggregated data. Inclusion of Turkey into the group of transition countries strengthens the test results in favor of weak form PPP. That verifies the significance of the extent of trade relationship as one of the requisite for the PPP hypothesis to hold.

Price Level Convergence, Purchasing Power Parity and Multiple Structural Breaks in Panel Data Analysis: An Application to U.S. Cities

This article provides a methodological and empirical approach for assessing price level convergence and its relation to purchasing power parity (PPP) using annual price data for seventeen U.S. cities during the period 1918 to 2005. We suggest a new panel data procedure that can handle a wide range of PPP concepts in the presence of multiple structural breaks using all possible pairs of real exchange rates. Testing for PPP requires the definition of parametric restrictions (parity restrictions) across regimes. In general, we find more evidence for stationarity when the parity restriction is not imposed, while imposing parity restriction leads toward the rejection of the panel stationarity. Our results can be embedded in the view of the Balassa-Samuelson approach, but where the slope of the time trend is allowed to change in the long-run.

Purchasing Power Parity under Regime Shifts: An Application to Asian Countries*

This paper re‐examines the long‐run purchasing power parity (PPP) relationship for nine Asian countries relative to the USA and Japan during a period containing significant structural breaks. The relevance of considering structural breaks in PPP tests is demonstrated by utilizing the Johansen et al. (2000) procedure that allows for up to two pre‐determined structural breaks. Using conventional tests without considering breaks, one is able to reject the null of no cointegration for only four countries. The Johansen et al. procedure clearly demonstrates the importance of allowing for structural breaks and provides strong support for long‐run PPP for all the countries, regardless of the base country, except in the case of the Philippines vis‐à‐vis Japan. The Hansen–Johansen parameter constancy test indicates stability for all the countries except the Philippines relative to the USA and Malaysia relative to Japan.

Are Asian real exchange rates mean reverting? Evidence from univariate and panel LM unit root tests with one and two structural breaks

There are a number of studies that examine the purchasing power parity (PPP) hypothesis. The empirical findings from the extant literature for the PPP hypothesis are mixed. This article applies univariate and panel Lagrange Multiplier (LM) unit root tests with one and two structural breaks to real exchange rates for 15 Asian countries. The univariate LM unit root tests find evidence of PPP for two-thirds of the sample. The results from the panel LM unit root test support long-run PPP for the Asian countries in the sample. The results from the LM panel unit root tests differ from those of existing panel unit root tests of PPP for Asian countries that have not allowed for the existence of structural breaks.

Testing purchasing power parity hypothesis for transition economies

This study tests the PPP hypothesis for transition economies by using a panel approach. The results show that PPP holds for transition economies suggesting a half-life convergence of about one year. This study also compares the convergence rates for ‘less open’ and ‘more open’ transition countries. It is found that ‘more open’ transition economies converge faster than ‘less open’ transition economies.

Mean reversion and structural breaks in real exchange rates: South African evidence

The paper tests for mean reversion, that is, purchasing power parity (PPP), in the bilateral real exchange rate series of the South African rand against those of the dollar, the pound sterling, the euro and the yen, these being the currencies of the country's main trading partners. The relevance of considering structural breaks in PPP tests is demonstrated. Using standard unit root tests without considering structural breaks, one is unable to reject the null hypothesis of a unit root in the exchange rate series. The additive outlier model clearly demonstrates the importance of multiple sudden structural breaks and supports the stationarity of the rand's bilateral real exchange rates. As expected the innovative outlier model, which seeks to suggest gradual shifts, only identifies a limited number of breaks and does not support mean reversion.

Extracting Inflation from Stock Returns to Test Purchasing Power Parity

Extracting Inflation from Stock Returns to Test Purchasing Power Parity

Purchasing Power Parity and the Asian Financial Crisis

Purchasing power parity (PPP) literature is now vast with literally hundreds of papers offering tests for PPP across a large number of countries. However, despite all the elaborate techniques employed, very little explanation is given as to why PPP is so relevant in policy making. This article provides a basic understanding of PPP and shows why it is considered so important when making policy choices. The discussion also briefly examines how this relates to the Asian economies. Primarily, these economies have been subject to intense scrutiny following the 1997 crisis, particularly with regard to their choice of exchange rate regime and possible monetary unification. The findings of the paper suggests that the PPP has had mixed results in predicting current account difficulties and liquidity crises, such as that experienced in Asia. However, the paper also argues that it still can form an integral part of an ‘early warning system’ designed to foresee economic crisis within a country.

Testing for PPP: Should we use panel methods?

A common finding in the empirical literature on the validity of purchasing power parity (PPP) is that it holds when tested for in panel data, but not in univariate (i.e. country-specific) analysis. The usual explanation for this mismatch is that panel tests for unit roots are more powerful than their univariate counterparts. In this paper we suggest an alternative explanation. Existing panel methods assume that cross-unit cointegrating relationships, that would tie the units of the panel together, are not present. Using simulations, we show that if this important underlying assumption of panel unit root tests is violated, the empirical size of the tests is substantially higher than the nominal level, and the null hypothesis of a unit root is rejected too often even when it is true. More generally, this finding warns against the “automatic” use of panel methods for testing for unit roots in macroeconomic time series.

Purchasing Power Parity Across States and Goods Within Australia*

Panel unit root tests show that intranational purchasing power parity cannot be rejected across major Australian cities from 1972:3 to 1999:1. The persistence of deviations in response to shocks is low, as measured by the estimated exact half‐life of between five and ten quarters. This is much lower than results for similar tests done on US cities, and for international purchasing power parity tests. The food CPI is largely responsible for the fast convergent results for city CPIs. Intranational purchasing power parity was rejected for the floating exchange rate period from 1984 to 1991 when inflation was high and not specifically targeted by the central bank.

PANEL COINTEGRATION: ASYMPTOTIC AND FINITE SAMPLE PROPERTIES OF POOLED TIME SERIES TESTS WITH AN APPLICATION TO THE PPP HYPOTHESIS

We examine properties of residual-based tests for the null of no cointegration for dynamic panels in which both the short-run dynamics and the long-run slope coefficients are permitted to be heterogeneous across individual members of the panel. The tests also allow for individual heterogeneous fixed effects and trend terms, and we consider both pooled within dimension tests and group mean between dimension tests. We derive limiting distributions for these and show that they are normal and free of nuisance parameters. We also provide Monte Carlo evidence to demonstrate their small sample size and power performance, and we illustrate their use in testing purchasing power parity for the post–Bretton Woods period.I thank Rich Clarida, Bob Cumby, Mahmoud El-Gamal, Heejoon Kang, Chiwha Kao, Andy Levin, Klaus Neusser, Masao Ogaki, David Papell, Pierre Perron, Abdel Senhadji, Jean-Pierre Urbain, Alan Taylor, and three anonymous referees for helpful comments on various earlier versions of this paper. The paper has also benefited from presentations at the 1994 North American Econometric Society Summer Meetings in Quebec City, the 1994 European Econometric Society Summer Meetings in Maastricht, and workshop seminars at the Board of Governors of the Federal Reserve, INSEE-CREST Paris, IUPUI, Ohio State, Purdue, Queens University Belfast, Rice University–University of Houston, and Southern Methodist University. Finally, I thank the following students who provided assistance in the earlier stages of the project: Younghan Kim, Rasmus Ruffer, and Lining Wan.

PPP tests in cointegrated panels: evidence from Asian developing countries

This study tests the relative version of purchasing power parity (PPP) for a set of ten Asian developing countries using a panel cointegration framework. A ‘between-dimension’ dynamic OLS estimator as proposed by Pedroni is employed. The test results overwhelmingly reject the PPP hypothesis.

Testing for Long-Run PPP in a System Context: Evidence for the Us, Germany and Japan

The present paper tests for the validity of long-run purchasing power parity (PPP) for the three key currencies of the recent floating exchange rate period, the US dollar, the German mark and the Japanese yen. The novelty of the paper is that the validity of the PPP conditions relating the economies of the US, Germany and Japan is tested in a system framework, which allows for possible interactions in the determination of the exchange rates and the prices of the three economies. Some form of causality among the variables of the system 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.

Paridade do poder de compra no Brasil: 1968 a 1994

Este artigo discute a relação entre os resultados dos testes para a validade da Paridade do Poder de Compra (PPC) no Brasil e fatos econômicos relevantes no período de 1968 a 1994. Este período se caracterizou por diversas alterações de política econômica, bem como das condições macroeconômicas da economia brasileira, que, por conseguinte, estão refletidas em mudanças nas propriedades estocásticas e na presença de quebras estruturais nas séries de índices de preços nacionais e taxa de câmbio nominal. Argumenta-se que a desconsideração destes problemas é a responsável pela obtenção de resultados contraditórios para os testes da versão absoluta da PPC. Por meio da realização de testes de raiz unitária com múltiplas quebras estruturais estas controvérsias são reavaliadas e produzidos novos resultados para a versão absoluta da PPC no Brasil, nesse período.

Extracting Inflation from Stock Returns to Test Purchasing Power Parity

Relative purchasing power parity (PPP) holds for pure price inflations, which affect prices of all goods and services by the same proportion, while leaving relative prices unchanged. Pure price inflations also affect nominal returns of all traded financial assets by exactly the same amount. Recognizing that relative PPP may not hold for the official inflation data constructed from commodity price indices because of relative price changes and other frictions that cause prices to be \sticky, we provide a novel method for extracting a proxy for realized pure price inflation from stock returns. We find strong support for relative PPP in the short run using the extracted inflation measures.