Are house prices in South Africa really nonstationary? Evidence from SPSM-based panel KSS test with a Fourier function

This study applies the sequential panel selection method (SPSM) to investigate the time-series properties of provincial house prices for entire, large, medium and small middle-segments of South Africa. Quarterly time-series data were collected from nine provinces in South Africa for different house-size categories over the period of 1978.Q1 to 2012.Q4. Whereas other panel-based unit-root tests are joint tests of a unit root for all members of a panel and are incapable of determining the mix of integrated of order zero (I(0)) series and integrated of order one (I(1)) series in a panel setting, the SPSM proposed by Chortareas and Kapetanios (2009) can clearly identify how many and which series in the panel are stationary processes by classifying a whole panel into a group of stationary and nonstationary series. The empirical results from several panel-based, as well as standard pure time-series, unit-root tests, indicate that house prices for the nine provinces studied here are either stationary or nonstationary. However, results from the SPSM using the panel version of the Kapetanios et al. (KSS, 2003) test with a Fourier function unequivocally indicate that house prices are stationary for the nine provinces under study. Our test results have important economic and policy implications for South Africa.     

Does real U.K. GDP have a unit root? Evidence from a multi-century perspective

ABSTRACT

We employ linear and nonlinear unit-root tests to examine the stationarity of five multi-century historical U.K. series of real output compiled by the Bank of England. Three series span 1270 to 2016 and two series span 1700 to 2016. These datasets represent the longest span of historical real output data available and, thus, provide the environment for which unit-root tests are most powerful. A key feature of our test is its simultaneous allowance for two types of nonlinearity: time-dependent (structural breaks) nonlinearity and state-dependent (asymmetric adjustment) nonlinearity. The key finding of the test, contrary to what other more popular nonlinear unit-root tests suggest, provides strong evidence that the main structure of the five series is a stationary process characterized by an asymmetric nonlinear adjustment and a permanent break affecting both the intercept and the trend. A major policy implication of this finding is fiscal and/or monetary stabilization policies have only temporary effects on the output levels of the United Kingdom.     

Unemployment by Gender: Evidence from EU Countries

This paper applies panel unit-root tests that allow for structural breaks and cross-sectional dependence to examine the validity of hysteresis in gender unemployment rates and gender unemployment gap for a panel of 15 European countries. Addressing breaks, there is evidence to reject the null hypothesis of hysteresis for the unemployment rates and unemployment gap series. Allowing for both cross-sectional dependence and heterogeneous structural breaks, this result is reverted, and we fail to reject the null hypothesis of unit root.     

Non-parametric tests of real exchange rates in the post-Bretton Woods era

This paper examines the mean-reverting property of real exchange rates. Earlier studies have generally not been able to reject the null hypothesis of a unit-root in real exchange rates, especially for the post-Bretton Woods floating period. The results imply that long-run purchasing power parity does not hold. More recent studies, especially those using panel unit-root tests or nonlinear time series models, have found more favorable results, however. But the results from these recent studies are far from conclusive. Consistent individual country time series evidence that supports long-run purchasing power parity continues to be scarce. In this paper, we test for long memory using (Lo’s in Econometrica 59:1279–1313, 1991) the modified rescaled range test, and the rescaled variance test of Giraitis et al. (J Econ 112:265–294, 2003a). Our testing procedure provides a non-parametric alternative to the parametric tests commonly used in this literature. Our data set consists of monthly observations from April 1973 to April 2001 of the G-6 countries (excluding the US) in the OECD. Using the modified rescaled range test, we find only 2 cases out of 15 where the null hypothesis of a unit-root with short-term dependence could be rejected in favor of the alternative hypothesis of long-term dependence and none using the rescaled variance test. Our results therefore do not provide strong empirical support for the stationarity of real exchange rates.     

A wavelet-based panel unit-root test in the presence of an unknown structural break and cross-sectional dependency,with an application of purchasing power parity theory in developing countries

This article introduces two different non-parametric wavelet-based panel unit-root tests in the presence of unknown structural breaks and cross-sectional dependencies in the data. These tests are compared with a previously suggested non-parametric wavelet test, the parameteric Im-Pesaran and Shin (IPS) test and a Wald type of test. The results from the Monte Carlo simulations clearly show that the new wavelet-ratio tests are superior to the traditional tests both in terms of size and power in panel unit-root tests because of its robustness to cross-section dependency and structural breaks. Based on an empirical Central American panel application, we can, in contrast to previous research (where bias due to structural breaks is simply disregarded), find strong, clear-cut support for purchasing power parity (PPP) in this developing region.     

Sustainability of current accounts: evidence from the quantile unit-root test

Regarding the stationarity of current accounts, previous studies used panel unit-root tests to improve the power of augmented Dickey–Fuller (ADF) test. This paper applies a quantile autoregression (QAR) approach to improve ADF test in the presence of outliers, and found that first, the stationarity was present in a QAR framework, rather than ADF test. Second, current accounts exhibited symmetric (e.g. Taiwan) and asymmetric patterns, which showed that positive shocks in larger quantiles induce current accounts to adjust towards a long-term equilibrium for Korea, Thailand, the Philippines and Singapore. Japan exhibited an asymmetric pattern in response to negative shocks in smaller quantiles.     

Time-Series Based Empirical Assessment of Random Urban Growth: New Evidence from France

Modern urban growth literature frequently uses unit-root tests in order to check the empirical relevance of Gibrat’s law of random growth. The contradictory nature of the test results provided by this literature is most likely linked to the low power of unit-root tests. To address this problem, we apply unit-root testing to a large-sized sample of high-quality French census data covering an exceptionally long time span of more than two centuries. We add subsequent cointegration tests in order to detect the possible presence of cointegrated random growth, which may reflect the fact that cities with a similar economic structure react fairly similarly to exogenous growth shocks. According to the test results, the random growth hypothesis cannot be rejected for a very large majority of the tested French cities; on the other hand, the null hypothesis of absence of cointegration cannot be rejected in more than 95% of the cases. Our findings therefore provide empirical support for non-cointegrated random growth.

     

Revisiting Purchasing Power Parity in OECD

This study revisits Purchasing Power Parity theory (PPP) in the 34 OECD countries during January 1994–August 2013. We use a new panel stationary test with both sharp breaks and smooth shifts, a novel approach to panel unit-root testing, proposed by Bahmani–Oskooee et al. (2014). The results indicate that the PPP holds in half of the 34 OECD countries. These results indicate the importance of proper modelling of both sharp breaks and smooth shifts in real effective exchange rate series of OECD countries.     

Does output have a unit root? New international evidence

In this paper unit-root tests for per capita output of 12 OECD countries are performed. Using traditional unit-root tests, it follows that the unit-root hypothesis cannot be rejected except for the US. However, following the approach of Perron (1989), which takes shifts in mean and/or trend into account, the null hypothesis of a unit-root can be rejected in most countries in our sample. In contrast to Perron, a method suggested by Christiano (1992)is used to determine the break date endogenously.     

Convergence in income inequality? evidence from panel unit root tests with structural breaks

This paper empirically tests whether there is evidence of convergence in income inequality, as predicted by several versions of the neoclassical growth model, using a large panel of annual data for the 48 contiguous states in the US over the 1916?C2005 period. By implementing the panel LM unit root test developed by Im et?al. (Oxford Bull Econ Stat 67:393?C419, 2005, Panel LM unit-root tests with trend shifts, Mimeo, 2010) that allows for the presence of structural breaks and heterogeneity in the panel, we find overwhelming evidence in support of convergence in income inequality. In addition, the results are robust to alternative inequality indicators used, different notions of stochastic convergence defined, and additional cross-sectional correlation considered.     

On real interest rate persistence: the role of breaks

The role of structural breaks in long spans of ex-post real interest rates for 10 industrialized countries is studied. First, the persistence of the real interest is assessed with newly proposed low-frequency tests of Müller and Watson (2008). Second, the test of Leybourne et al. (2007) for a change in persistence of a time series is applied to the real interest rate. The results show that real interest rates over the full sample period do not fit a covariance-stationary or unit-root model, nor a fractionally integrated, near-unit-root or local-level model. Instead, the persistence of real rates changes over time and there are periods when the real rate is covariance-stationary and other periods when it follows a unit-root process.     

Evidence of Wagner's law from Indian states

In this paper, we test for Wagner's law for 15 Indian states. We consider nine panels of states based on geography and level of economic development. Using panel unit-root, panel-cointegration, and panel-Granger causality analysis, we unravel strong evidence of Wagner's law. However, we find that the Wagner's law relationship is consumption rather than capital expenditure driven. This is a fresh revelation and our results are robust to different model specifications.     

Revisiting purchasing power parity for major OPEC countries: evidence based on nonlinear panel unit-root tests

In this study, we apply nonlinear panel unit-root test to assess the nonstationary properties of the real exchange rate for seven major Organization of the Petroleum Exporting Countries (OPEC). We find that nonlinear panel unit-root test has higher power than linear method suggested by Breuer et al. (2001 Breuer, J. B., McNown, R. and Wallace, M. S. 2001. Misleading inferences from panel unit-root tests with an illustration from purchasing power parity. Review of International Economics, 9: 482–93. [Crossref] , [Google Scholar]) if the true data generating process of exchange rate is in fact a stationary nonlinear process. We re-examine the validity of Purchasing Power Parity (PPP) from the panel nonlinear point of view and provide robust evidence clearly indicating that PPP holds true for four countries, namely Angola, Indonesia, Iran and Saudi Arabia. Our findings point out their exchange rate adjustment is mean reversion towards PPP equilibrium values in a nonlinear way.     

Oil Exports, Non-Oil GDP, and Investment in the GCC Countries

This paper studies the long-run and short-run relationships between oil exports, non-oil GDP, and investment in five major oil-exporting countries. Its goal is to verify the effect of natural resources exports on economic performance. It considers the effect of cross-sectional correlations and uses the corresponding panel unit-root tests to study the long-run characteristics of the data series. The results show that resources' exports have no long-run relationship with the macroeconomic variables. A VAR analysis is used to estimate the short-run dynamics and shows that the effect of oil exports on those variables depends on local policies.     

A REVISIT TO THE STATIONARITY OF OECD INFLATION: EVIDENCE FROM PANEL UNIT‐ROOT TESTS AND THE COVARIATE POINT OPTIMAL TEST*

This paper re‐examines the stationarity of inflation rates in 19 Organisation for Economic Cooperation and Development countries with the use of cross‐sectional information. We employ the panel unit‐root tests that allow for cross‐sectional dependency and the covariate point optimal test. These tests have high power in common due to the exploitation of cross‐sectional information, and they can assist mutually to draw a concrete conclusion on inflation dynamics for all series in the panel. Our empirical results show that allowing for cross‐sectional dependency rejects the null hypothesis that all series in the panel have a unit root, implying that there is at least one stationary series in the panel. With the help of the results of the covariate test, we can distinguish the panel into a group of stationary and a group of non‐stationary series. For robustness, the two groups of series are re‐confirmed by the panel tests. Our results reveal evidence of mean reversion in inflation for 15 of 19 countries, which is significantly stronger as compared to that obtained by the state‐of‐the‐art univariate unit‐root tests.     

Unemployment Hysteresis in Australian States and Territories: Evidence from Panel Data Unit Root Tests

This article tests for hysteresis by applying panel data unit root tests to quarterly unemployment rates for Australian states and territories between 1982:2 and 2002:1. Panel tests proposed by Levin and Lin (1992) using ordinary least squares and O'Connell (1998) using feasible generalised least squares (which assume that under the alternative hypothesis of stationarity, all labour markets revert to the natural rate at the same speed) provide evidence in support of the natural rate hypothesis. However, the panel test proposed by Im, Pesaran and Shin (1997), which does not assume that all cross‐sectional units converge towards the equilibrium value at the same speed under the alternative and is therefore less restrictive than the other two panel tests, finds evidence of hysteresis. Given the advantages of the Im et al. (1997) test over the other two panel tests the results can be interpreted as being consistent with the existence of hysteresis in unemployment     

A Nonparametric Test for I(0)

There is frequently interest in testing that a scalar or vector time series is I(0), possibly after first-differencing or other detrending, while the I(0) assumption is also taken for granted in autocorrelation-consistent variance estimation. We propose a test for I(0) against fractional alternatives. The test is nonparametric, and indeed makes no assumptions on spectral behaviour away from zero frequency. It seems likely to have good efficiency against fractional alternatives, relative to other nonparametric tests. The test is given large sample justification, subjected to a Monte Carlo analysis of finite sample behaviour, and applied to various empirical data series.     

Moran's I test of spatial panel data model — Based on bootstrap method

Under the condition of the finite sample or the unknown distributed error term, testing for spatial dependence in panel data models is an unresolved problem in spatial econometrics. In this paper, a fast double bootstrap (FDB) method is used to construct bootstrap Moran's I tests for Moran's I test in spatial panel data models, and Monte Carlo simulation experiments are used to prove the effectiveness from two aspects including size distortion and power. The experiment results show that, in asymptotic Moran's I test, there is serious size distortion, which could be rectified in bootstrap Moran's I test.     

Are US macroeconomic series difference stationary or trend-break stationary?

This article tests for the presence of a unit-root in all time series included in the extended Nelson–Plosser data set using the statistics devised by Zivot and Andrews, Perron and Murray and Zivot. It specifies the mixed model characterization of the trend-break stationary alternative that allows for a simultaneous break in both the intercept and slope of the trend-function. It rejects the unit-root null hypothesis for real GNP, nominal GNP, real per capita GNP, industrial production, employment, GNP deflator, nominal wages, interest rate and common stock prices. Use of appropriate critical values to assess the significance of the trend-function coefficients reveals that the slope-break should be included in real GNP, nominal GNP, real per capita GNP, nominal wages, interest rate and common stock prices. The results indicate that there is less evidence against the unit-root hypothesis with the extended Nelson–Plosser data compared to the original Nelson–Plosser data.     

New tests for stationarity and parity reversion: Evidence on New Zealand real exchange rates

The present paper discusses the stochastic stationarity of New Zealand exchange rates in light of new time series methods and new tests. The question of whether the real exchange rates have a unit root or are mean reverting is set in the general framework of fractionally integrated models. The estimates sustain the claim that New Zealand real exchange series are not stationary. However, it is shown that nonstationarity is compatible with parity reversion in the framework of fractional unit-root models.