Nonlinear Mean Reversion across National Stock Markets: Evidence from Emerging Asian Markets

This paper seeks empirical evidence of nonlinear mean-reversion in relative national stock price indices for Emerging Asian countries. It is well known that conventional linear unit root tests suffer from low power against the stationary nonlinear alternative. Implementing the nonlinear unit root tests proposed by Kapetanios et al. (2003 Kapetanios, G., Shin, Y. and Snell, A. 2003. Testing for a unit root in the nonlinear STAR framework. Journal of Econometrics, 112: 359–379. [Crossref], [Web of Science ®] , [Google Scholar]) and Cerrato et al. (2009 Cerrato, M., de Peretti, C., Larsson, R. and Sarantis, N. 2009. “A nonlinear panel unit root test under cross section dependence”. Working Papers 28, Department of Economics, University of Glasgow [Google Scholar]) for the relative stock prices of Emerging Asian markets, we find strong evidence of nonlinear mean reversion, whereas linear tests fail to reject the unit root null for most cases. We also report some evidence that stock markets in China and Taiwan are highly localized.     

Does the Law of One Price Hold within the EU? A Panel Analysis

This paper empirically tests the law of one price by applying unit root tests to three panels consisting of data on 90 consumer price indices for the EU-25, the EU-15 and the 10 new EU member countries that joined the EU in 2004. The four major findings of this paper are: (1) panel unit root tests find evidence of price convergence for about 70% of all product groups, (2) the results are sensitive to the choice of the numeraire country implying that any conclusions must be based on all bilateral combinations, (3) the average half life across all product groups is 2.0 years, (4) the overall evidence for the law of one price is weaker in the 10 new EU member countries than in the EU-15.

Panel asymmetric nonlinear unit root test and PPP in Africa

This study revisits purchasing power parity (PPP) theory for 20 African countries using panel asymmetric nonlinear unit root test proposed by Emirmahmutoglu and Omay (2014), through the sequential panel selection method of Chortareas and Kapetanios (2009). While standard panel unit root tests fail to support the PPP, the empirical results from panel asymmetric nonlinear unit root test do support the PPP. However, additional tests reveal that support in all 20 African countries is mostly due to stationarity of the real effective exchange rates of Ghana and Rwanda where the adjustment process towards equilibrium is nonlinear and asymmetric.     

Testing uncovered interest rate parity using LIBOR

We test uncovered interest rate parity (UIP) using London InterBank Offered Rate (LIBOR) interest rates for a wide range of maturities. In contrast to other markets, LIBOR markets have minimal frictions. Whereas most previous studies reject UIP, we find that UIP holds for several short-term LIBOR maturities using block bootstrap panel unit root tests suggested by Palm et al. (2011) and cointegration techniques by Westerlund (2007). Furthermore, the estimation results suggest that the speed of adjustment to the long-run equilibrium marginally differs across the maturity of the underlying instrument, thus supporting the efficient market hypothesis.     

Panel LM unit root tests with level and trend shifts

This paper considers a Lagrange multiplier (LM) based panel unit root test that allows for heterogeneous structural breaks in both the intercepts and slopes of a series. We note that many popular time series variables are likely to exhibit changing means and/or trends over time. Given that the usual tests will depend on the nuisance parameters indicating the locations of the trend breaks, we adopt a transformation procedure that makes our new panel unit root tests invariant to the nuisance parameters. To illustrate the importance of the power gain provided by our test, we examine the convergence hypothesis using relative ratios of per capita health care expenditures in 20 OECD countries. Our results provide evidence that the convergence hypothesis is supported.     

PPP: Further evidence from Japanese regional data

This paper empirically analyzes Purchasing Power Parity (PPP) among Japanese municipalities from 1990 to 2003. Using panel unit root tests including one that considers cross-sectional dependence in the data (e.g., [Moon, H. R. and Perron, B. (2004). Testing for a unit root in panels with dynamic factors. Journal of Econometrics, 112, 81–126.]), we find evidence in favor of PPP, confirming the stationarity of relative prices in Japan and thus the long-run co-movement of municipal prices. Furthermore, the half-life of a shock is found to be about 2 years, which is faster than that of the international PPP. As in the European and US studies, short-term deviations from PPP can be explained by income differentials and distance between cities.     

The Error-in-Rejection Probability of meta-analytic panel tests

The puzzling Monte Carlo finding that the size distortion of meta-analytic panel unit root tests increases with the number of panel series is explained as the cumulative effect of arbitrarily small size distortions in the time series tests composing the panel test.     

Inflation-targeting and real interest rate parity: A bias correction approach

This paper investigates whether inflation-targeting influences real interest rate parity (RIP) by a bias correction approach under cross-sectional dependence. The recursive mean adjustment (RMA) method proposed by So and Shin (1999) and Shin and So (2001) is employed to correct the downward bias in the panel unit root tests and in the half-life estimates of real interest rate differentials for traded and non-traded goods. The empirical findings differ depending on whether we apply the RMA. More importantly, the empirical results show that as more homogeneous economies become involved in terms of inflation-targeting regime, stronger mean reversion and much a tighter confidence interval are present. Thus, inflation-targeting plays an important role in providing favorable evidence for long-run RIP.     

Are CO2 Emission Levels Converging Among Industrial Countries?

Time paths of carbon dioxide emissions intwenty-one industrial countries are examinedfrom 1960–1997 to test for stochastic andconditional convergence. Both panel unit roottests and cross-section regressions areperformed. Overall, we find significantevidence that CO₂ emissions haveconverged.     

BOOTSTRAPPING COVARIATE UNIT ROOT TESTS: AN APPLICATION TO INFLATION RATES

This paper proposes a bootstrap procedure for the covariate point optimal tests (CP_T) of Elliott and Jansson. Although the covariate tests enjoy large power gains over the traditional univariate unit root tests, our simulations show that they still suffer from severe size distortions at finite samples. Through simulations, we demonstrate the superiority of the bootstrap procedure in the sense that it can yield desirable size and power properties for the CP_T tests when the Akaike's information criterion is used. Moreover, we show the empirical relevance of the bootstrap tests by applying them to inflation in the G‐10 countries, and then obtain strong evidence against the unit root hypothesis for most countries at the 5% significance level.     

Testing for Convergence in Carbon Dioxide Emissions Using a Century of Panel Data

This paper tests the convergence in per-capita carbon dioxide emissions for a collection of developed and developing countries using data spanning the period 1870–2002. For this purpose, three recently developed panel unit root tests that permit for dependence among the individual countries are employed. The results lend strong support in favor of convergence for the panel as a whole. Estimates of the speed of this convergence is also provided.      

Data-dependent selection of the lag truncation parameter in unit root tests of the Phillips-Perron type

The Andrews (Econometrica, 1991, 59, 817–858) plug-in method of heteroscedastic and autocovariance consistent covariance matrix estimation is used to construct estimators of the long-run variance parameter for use in Phillips-Perron unit root tests. This allows the lag truncation parameter to be data dependent. Monte Carlo size and power estimates are obtained suggesting that this apparently natural approach does not provide significant improvements in test performance.     

An empirical test of purchasing power parity in selected developing countries: a panel data approach

Abstract

This paper examines the empirical validity of Purchasing Power Parity (PPP) for certain large developing economies by using a panel unit root methodology. The test results show that a long run real exchange rate depreciation trend exists in certain developing countries. Without considering this depreciation trend, it is hard to verify the stationarity and to explain the existence of the extremely long half-lives of the real exchange rates. When a linear time trend is included in the tests, the results tend to support the stationarity of the underlying real exchange rate processes, and the half-lives are significantly shorter and their range can be explained by transitory disturbances.     

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.First version received: November 2001/Final version received : October 2003     

Quantile unit root test and the PPP in Africa

In this study, we apply the Quantile unit root test and revisit the Purchasing Power Parity (PPP) in 20 African countries using real effective exchange rates over the period 1971Q1 to 2012Q4. While traditional unit root tests fail to reject unit root hypothesis in most of the countries, results from Quantile unit root test reject unit root null hypothesis in Ghana, Mauritius, Niger, South Africa, and Togo, providing support for the PPP at least in these five countries. We further estimate the half-life based on Quantile autoregressive (QAR) model to be about 4.57–7.96 quarters (1–2 year).     

The inflation rates may accelerate after all: panel evidence from 19 OECD economies

The stationarity of inflation has many important economic implications. Most panel-based empirical studies do not handle cross-sectional dependence, which will result in power distortion. This paper applies a nonlinear IV estimator to calculate the test statistic of panel unit root (Chang in J Econom 110:261–292, 2002), which accounts for general cross-sectional correlation. Using monthly inflation rates, two statistics proposed by Im et al. (J Econom 115:53–74, 2003) reject the unit root; however, the nonlinear IV statistic accepts the unit root. That is, the ignored cross-sectional correlation may lead to over-rejection of the unit root null. In a nutshell, unlike current literature, the inflation rates may accelerate after all.     

Do energy prices converge across Russian regions?

This paper tests for price convergence in Russian energy markets from January 2003 to October 2010. Monthly energy prices for four energy products (diesel, gasoline, electricity and coal) for 83 Russian regions are drawn from Russia's statistical agency Rosstat. The study contributes to the existing literature by using the Exponential Smooth Auto-Regressive Augmented Dickey–Fuller unit root test in a panel setup, which encompasses cross-section dependence. We find that there are no fully integrated national energy markets in Russia, possibly due to the peripheral position of diverging regions, unbalanced distribution of energy reserves and limited cross-border transmission capacity.     

On the joint Fourier–ESTAR testing of PPP

The purchasing power parity (PPP) is the hypothesis that the real exchange rate series are stationary. This study briefly reviews and applies six competing unit root test procedures to test PPP. Reflecting the existing literature, the results are mixed. The Kiliç test is the most favourable while the Kapetanios, Shin, and Snell (KSS) test is the least favourable to PPP and the standard ADF test lies in between. The same conclusion applies to the Fourier extensions of those three tests. The results support a recently suggested F-test for the significance of Fourier terms in unit root test equations.     

Unit Root Tests for Dependent Micropanels

This paper proposes a new test for the null hypothesis of panel unit roots for micropanels with short time dimensions (T) and large cross‐sections (N). There are several distinctive features of this test. First, the test is based on a panel AR(1) model allowing for cross‐sectional dependency, which is introduced by a factor structure of the initial condition. Second, the test employs the panel AR(1) model with AR(1) coefficients that are heterogeneous for finite N. Third, the test can be used both for the alternative hypothesis of stationarity and for that of explosive roots. Fourth, the test does not use the AR(1) coefficient estimator. The effectiveness of the test rests on the fact that the initial condition has permanent effects on the trajectory of a time series in the presence of a unit root. To measure the effects of the initial condition, the present paper employs cross‐sectional regressions using the first time‐series observations as a regressor and the last as a dependent variable. If there is a unit root in every individual time series, the coefficient of the regressor is equal to one. The t‐ratios for the coefficient are this paper's test statistics and have a standard normal distribution in the limit. The t‐ratios are based on the OLS estimator and the instrumental variables estimator that uses reshuffled regressors as instruments. The test proposed in this paper makes it possible to test for a unit root even at T = 2 as long as N is large. Simulation results show that test statistics have reasonable empirical size and power. The test is applied to college graduates' monthly real wage in South Korea. The number of time‐series observations for this data is only two. The null hypothesis of a unit root is rejected against the alternative of stationarity.     

Testing the purchasing power parity in panel data

This paper empirically tests the purchasing power parity (PPP) using panel unit root tests. We employ a battery of panel unit root tests: LM-bar statistic [Testing for unit roots in heterogeneous panels, Working paper, University of Cambridge] is employed to account for serially correlated errors. The statistic proposed by Breitung [Adv. Econom. 15 (2000) 161.] and the KPSS-based statistic of Hadri [Econ. J. 3 (2000) 148.] are also used. In addition, we also employ a SUR estimator to account for possible cross-sectional effect. Data of 45 economies from 1980 to 1999 are used to test the PPP hypothesis. We find that these estimators tend to get supportive results when the data frequency becomes lower, which substantially characterizes the long-run property of the PPP hypothesis.