Time-specific disturbances and cross-sectional dependency in a small-sample heterogeneous panel data unit root test

In their seminal work, Im et al. (1997 Im, KS, Pesaran, MH and Shin, Y. 1997. Testing for unit roots in heterogeneous panels. 1997. Working paper, Department of Applied Economics, University of Cambridge. Mimeographed [Google Scholar], 2003 Im, KS, Pesaran, MH and Shin, Y. 2003. Testing for unit roots in heterogeneous panels. Journal of Econometrics, 115: 53–74. [Crossref], [Web of Science ®] , [Google Scholar]) suggested that time series for several cross-sectional units could be used to increase the power of the Dickey--Fuller unit root test. They argued that when cross-sectional correlation is a problem that can be modelled by a time-specific factor, demeaning across the cross-sectional units can solve the problem. In this study, this proposition is proven valid, but it is also shown that previously supplied standardizing moments are inappropriate when the number of cross-sections are small, causing size to differ from the significance level. To correct this size distortion, the current paper supplies response surface parameters that can be used to obtain moments that are valid when a time-specific factor suffices for modelling cross-sectional correlation in the heterogeneous panel data unit root framework. The correct size of the panel data unit root test comes at the cost of a somewhat lower power against a stationary alternative.     

Towards solving the PPP puzzle: evidence from 113 countries

Several different approaches have been followed by researchers to test the validity of Purchasing Power Parity (PPP). Since the introduction of the unit-root tests, researchers have applied a battery of these tests to determine whether the real exchange rates are stationary. If the answer is in the affirmative, PPP is validated. While application of the standard augmented Dickey–Fuller test has not provided much support for PPP, a test that incorporates nonlinearity in the rates has. Under both tests, however, the null of nonstationary is tested against the alternative of stationarity. In this article, when we switch the null with the alternative and apply Kwiatkowski et al. (1992 Kwiatkowski, D, Phillips, PCB, Schmidt, P and Shin, Y. 1992. Testing the null hypothesis of stationarity against the alternative of a unit root. Journal of Econometrics, 54: 159–78. [Crossref], [Web of Science ®] , [Google Scholar]) test, we provide relatively more support for the theory, getting closer and closer towards solving the PPP puzzle.     

Unit roots and purchasing power parity: another kick at the can

Lopez et al. (2005 Lopez, C, Murray, C and Papell, D. 2005. State of the art unit root tests and purchasing power parity. Journal of Money, Credit and Banking, 37: 361–9. [Crossref], [Web of Science ®] , [Google Scholar]) demonstrated that single-equation unit-root tests cannot provide conclusive evidence of whether real exchange rates are stationary because inference depends critically on the lag-lengths used to construct the test statistics, a result reinforced by a recent work by Sweeney (2006 Sweeney, D. 2006. Mean reversion in nominal G-10 exchange rates. Journal of Financial and Quantitative Analysis, 41: 685–708. [Crossref], [Web of Science ®] , [Google Scholar]). The purpose of this article is to revisit the issue, first demonstrating the necessary conditions under which this approach of testing for Purchasing Power Parity (PPP) is appropriate.     

Sustainability of external debt: further evidence from non-linear framework

This study investigates sustainability of external debt under a two-step non-linear framework. The first step uses a general linearity test proposed by Harvey and Leybourne (2007 Harvey, David I. and Leybourne, Stephen J. 2007. Testing for time series linearity. Econometric Journal, 10: 149–165. [Crossref], [Web of Science ®] , [Google Scholar]) to determine the linearity property of external debt. The second step applies a non-linear ADF unit root test proposed by Kapetanios, Shin, and Snell (2003 Kapetanios, G., Y. Shin, and A. Snell. 2003. Testing for a unit root in the nonlinear STAR. Journal of Econometrics 112: 359–79.  [Google Scholar]) on the non-liner processes and the linear ADF test on the linear processes to examine the sustainability of external debt. The analysis of 36 debt and 55 current account ratios identifies strong evidence of non-linearity and sustainability. The results indicate superior performance of the non-linear unit root test over the ADF test in determining the stationary property of the data.     

Trend stationary of inflation rates: evidence from LM unit root testing with a long span of historical data

The article applies the LM univariate unit root test recently developed by Lee and Strazicich (2003 Lee, J and Strazicich, MC. 2003. Minimum Lagrange multiplier unit root test with two structural breaks. The Review of Economics and Statistics, 85: 1082–9. [Crossref], [Web of Science ®] , [Google Scholar], 2004 Lee, J and Strazicich, MC. 2004. Minimum LM unit root test with one structural break, Department of Economics, University of Central Florida. Working Paper Series [Google Scholar]) to re-examine the validity of trend stationary in the inflation rates of 11 OECD and Asian countries using a longer span of historical data. Our empirical findings are favourable to the trend stationary of the inflation rates when we control the structural breaks in series, and therefore they point to the absence of hyperinflation in the majority of the countries. The results indicate that shocks to inflation rates are temporary and soon converge, with the inflation rates being trend stationary. Hence, most structural breaks in the inflation rate occur around the Great Depression, World War I, World War II, and energy shock periods. For the convergence effect, we repeat the unit root tests utilized above for smaller sub-samples so as to provide a robust analysis. The outcomes show that by selecting a longer data span, we can catch more powerful convergent evidence. Overall, some policy implications are obtained in this article.     

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.     

Further investigation of the uncertain trend in US GDP

The presence of deterministic or stochastic trend in US GDP has been a continuing debate in the literature of macroeconomics. Ben-David and Papell (1995 Ben-David, D and Papell, DH. 1995. The great wars, the great crash, and steady growth: some new evidence about an old stylized. Journal of Monetary Economics, 36: 453–75. [Crossref], [Web of Science ®] , [Google Scholar]) found evidence in favour of trend stationarity using the secular sample of Maddison (1991 Maddison, A. 1991. Dynamics Forces in Capitalist Development: A Long-Run Comparative View, Oxford: Oxford University Press.  [Google Scholar]). More recently, Murray and Nelson (2000 Murray, CJ and Nelson, CR. 2000. The uncertain trend in U.S. GDP. Journal of Monetary Economics, 46: 79–95. [Crossref], [Web of Science ®] , [Google Scholar]) correctly criticized this finding arguing that the Maddision data are plagued with additive outliers (AO), which bias inference towards stationarity. Hence, they propose to set the secular sample aside and conduct inference using a more homogeneous but shorter time-span post-WWII sample. In this article we re-visit the Maddison data by employing a test that is robust against AO's. Our results suggest the US GDP can be modelled as trend stationary process     

Does PPP hold in African countries? Further evidence based on a highly dynamic non-linear (logistic) unit root test

With a view to investigating whether the purchasing power parity (PPP) theory holds true for selected African countries during the January 1980–December 2003 period, we employ a rigorous, highly dynamic non-linear (logistic) unit root test, as first advanced by Leybourne et al. (1998 Leybourne, S, Newbold, P and Vougas, D. 1998. Unit roots and smooth transitions. Journal of Time Series Analysis, 19: 83–97. [Crossref] , [Google Scholar]), which is considerably more powerful than those tests traditionally used. Compared with the rejection of the null of the unit root process for only one of the 22 countries under study when we use the traditional ADF, PP, KPSS, NP and the DF-GLS unit root tests, with the Leybourne et al. (1998 Leybourne, S, Newbold, P and Vougas, D. 1998. Unit roots and smooth transitions. Journal of Time Series Analysis, 19: 83–97. [Crossref] , [Google Scholar]) test, we strongly reject the null of the unit root process for a surprising six of the 22 countries. These empirical results clearly indicate that PPP holds true for these six countries, namely the Central African Republic, the Côte d’Ivoire, Kenya, Madagascar, Uganda and Lesotho.     

Convergence in household credit demand across euro area countries: evidence from panel data

This article contributes to the literature on the convergence of financial systems in the euro area by estimating household credit demand in individual countries. Using the ARDL framework advocated notably by Pesaran et al. (1999 Pesaran, MH, Shin, Y and Smith, RP. 1999. Pooled mean group estimation of dynamic heterogeneous panels. Journal of the American Statistical Association, 94: 621–34. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]), the article provides evidence on the convergence of long-run credit demand determinants (interest rates, investment and house prices) in the largest euro area countries, while short run-dynamics remain heterogenous across countries. The article also demonstrates that the equation uncovers demand rather than supply behaviour.     

Structural changes and regional disparity in China's inflation: a revisit

The study re-examined the time series properties and regional disparities in Chinese inflation by extending the work of Chong, Zhang, and Feng (2011 Chong, Tai-Leeung, Terence, Ning Zhang and Feng, Qu. 2011. Structural Changes and Regional Disparity in China's Inflation. Economics Bulletien, 31(1): 572–583.  [Google Scholar]). For this purpose we employed the Lagrange Multiplier (LM) unit root test with one structural break and two structural breaks suggested by Lee and Strazicich (2003 Lee, Junsoo, Mark, C. and Strazicich. 2003. Minimum LM Unit Root Test with Two Structural Breaks. Review of Economics and Statistics, 85(4): 1082–1089. [Crossref], [Web of Science ®] , [Google Scholar], 2004 Lee, J. and Strazicich, M. 2004. Minimum LM unit root test with one structural break. Working Paper 04–17, Boone, North Carolina: Department of Economics, Appalachian State University.  [Google Scholar]) and a recently developed ADF type unit root test with two structural breaks of Narayan and Popp (2010 Narayan, Paresh Kumar and Stephan Popp. 2010. A New Unit root test with Two Structural Breaks in Level and Slope at Unknown Time. Journal of Applied Statistics, 37(9): 1425–1438. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]). We found that national, urban and rural series of the overall inflation series, clothing, and food, national series of education and residence and the rural series of residence and education are stationary. We also found regional disparity in Chinese inflation, but the disparities existed only in education inflation series.     

Within-groups wage inequality and schooling: further evidence for Portugal

This article provides further evidence on the positive impact of schooling on within-groups wage dispersion in Portugal, using data on male workers from the 2001 wave of the European Community Household Panel. The issue of schooling endogeneity is taken into account by using the latest available instrumental-variable technique for quantile regression, i.e. the control-function estimator due to Lee (2007 Lee, S. 2007. Endogeneity in quantile regresssion models: a control function approach. Journal of Econometrics, 141: 1131–58. [Crossref], [Web of Science ®] , [Google Scholar]). The findings are compared with earlier results based on different techniques, i.e. the instrumental-variable estimator due to Arias et al. (2001 Arias, O, Hallock, KF and Sosa-Escudero, W. 2001. Individual heterogeneity in the returns to schooling: instrumental variables quantile regression using twins data. Empirical Economics, 26: 7–40. [Crossref] , [Google Scholar]) and the standard exogeneity-based estimator due to Koenker and Bassett (1978 Koenker, R and Bassett, G. 1978. Regression quantiles. Econometrica, 46: 33–50. [Crossref], [Web of Science ®] , [Google Scholar]).     

Immiserizing Growth and the Metzler Paradox in the Ricardian Model

Conditions for the occurrence of immiserizing growth and the Metzler paradox are analysed in the Ricardian model when consumers in the foreign country have Leontief preferences while consumers in the home country have Cobb-Douglas preferences. By using specific functional forms, the conditions for the occurrence of the two paradoxes are defined in terms of the exogenous parameters of the model rather than endogenous variables such as the foreign import demand elasticity in the conditions of Bhagwati (1958) Bhagwati, J. N. 1958. Immiserizing growth: a geometrical note. Review of Economic Studies, 25: 201–205. [Crossref], [Web of Science ®] , [Google Scholar] and Metzler (1949a Metzler, L. A. 1949a. Tariffs, the terms of trade and the distribution of national income. Journal of Political Economy, 57: 1–29. [Crossref], [Web of Science ®] , [Google Scholar], b Metzler, L. A. 1949b. Tariffs, international demand, and domestic prices. Journal of Political Economy, 57: 345–351. [Crossref], [Web of Science ®] , [Google Scholar]). It is shown that the simultaneous occurrence of both paradoxical results is possible for some parameter values.     

Estimation of SEs for heteroscedastic and cross-sectionally correlated data

This study develops SE estimators for heteroscedastic and cross-sectionally correlated data. The new estimators are a cross-sectional version of the White and Domowitz (1984 White, H and Domowitz, I. 1984. Nonlinear regression with dependent observations. Econometrica, 52: 143–61. [Crossref], [Web of Science ®] , [Google Scholar]) and Newey and West (1987 Newey, W and West, K. 1987. A simple positive semi-definite, heteroscedasticity and autocorrelation consistent covariance matrix. Econometrica, 55: 703–8. [Crossref], [Web of Science ®] , [Google Scholar]) estimators, and therefore, consistent in the presence of heteroscedasticity and cross correlation of unknown form. Unlike the estimators in the literature, these estimators can control for cross correlation even for single-period cross-sectional data.     

Financial development and economic growth nexus: a time-series evidence from India

This study examines the relationship between financial development and economic growth in India for the period 1951–52 to 1995–96. The long-run equilibrium and short-run dynamic models are estimated using financial interrelations ratio and new issue ratio as the measures of financial development, a la Goldsmith (1969 Goldsmith, RW. 1969. Financial Structure and Development, New Haven: Yale University Press.  [Google Scholar]). The Johansen (1991 Johansen, S. 1991. Estimation and hypothesis testing of cointegration vectors in Gaussian vector autoregressive models’. Econometrica, 59: 1551–80. [Crossref], [Web of Science ®] , [Google Scholar]) estimator rejects the null of zero cointegrating vector and shows the presence of long-run equilibrium relationship between financial development and economic growth. The error correction model, impulse response and variance decomposition analyses (Sims, 1980 Sims, CA. 1980. Macroeconomics and reality. Econometrica, 48: 1–48. [Crossref], [Web of Science ®] , [Google Scholar]), and the Toda and Yamamoto (1995 Toda, HY and Yamamoto, T. 1995. Statistical inference in vector autoregressions with possibly integrated processes. Journal of Econometrics, 66: 225–50. [Crossref], [Web of Science ®] , [Google Scholar]) estimator show the presence of bidirectional Granger-causality between financial development and economic growth. The presence of bidirectional Granger-causality suggested by these estimators points towards the possible problem of endogeneity and simultaneity bias in the growth models that examine the contemporaneous effect of financial development on economic growth. The economic reforms that started since July 1991 emphasized on the liberalization and development of financial sector to supplement the efforts aimed at achieving high economic growth in India.     

Salaried employment and earnings in Indonesia: new evidence on the selection bias

This article uses household survey data to estimate the determinants of earnings in Indonesia, a country where nonsalaried work is widespread and earnings data are available for salaried employees only. We deal with the selection bias by estimating a Full-Information Maximum Likelihood (FIML) system of equations, where selection into the labour market is modelled in a multinomial setting. We find that some estimated parameters of the earnings equation differ from a binomial selection procedure by Heckman (1979 Heckman, J. 1979. Sample selection bias as a specification error. Econometrica, 47: 153–61. [Crossref], [Web of Science ®] , [Google Scholar]), in particular for those variables with the strongest impact on the selection into the different labour-market statuses. However, the estimated returns to education are unaffected, even when we deal with the endogeneity of educational attainment following Duflo (2001 Duflo, E. 2001. Schooling and labour market consequences of school construction in Indonesia: evidence from an unusual policy experiment. American Economic Review, 91: 795–813. [Crossref], [Web of Science ®] , [Google Scholar]). Overall, our findings show that the choice of the selection rule affects the estimates of the earnings determinants in the Indonesian labour market.     

Will the skill-premium in the Netherlands rise in the next decades?

While the skill-premium has been rising sharply in the US and the UK for 20 years, the Dutch skill-premium decreased for much of that period and only started to rise in the early 90s. In this article, we investigate whether the Dutch skill-premium will rise in the next decades. To answer this question, we forecast the skill-premium using the Katz and Murphy (1992 Katz, L and Murphy, K. 1992. Changes in relative wages, 1963–1987: supply and demand factors. Quarterly Journal of Economics, 107: 35–78. [Crossref], [Web of Science ®] , [Google Scholar]) and the Krusell et al. (2000 Krusell, P, Ohanian, L, Ríos-Rull, J-V and Violante, G. 2000. Capital-skill complementarity and inequality: a macroeconomic analysis. Econometrica, 68: 1029–53. [Crossref], [Web of Science ®] , [Google Scholar]) models. The Katz and Murphy model (KM) explains demand shifts by skill-biased technological change in unobservable variables captured by a time trend. In contrast, the Krusell et al. model (KORV) explains demand shifts by (observable) changes in the capital stock under a capital-skill complementarity technology. The results show that while the KM model predicts that the skill-premium will have increased by 30% in 2020, based on realistic predictions of the stock of capital, the KORV model predicts that the skill-premium will remain between ?5 and +5% of its 1996 level.     

A nonparametric revealed preference test of optimal intra-firm resource allocation

The collective rationality hypothesis initiated by Chiappori (1988a Chiappori, PA. 1988a. Rational household labor supply. Econometrica, 56: 63–89. [Crossref], [Web of Science ®] , [Google Scholar]) and applied by Seaton (1997 Seaton, JS. 1997. Neoclassical and collective rationality in household labour supply. Applied Economics Letters, 4: 529–33. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar], 2001) for a two-person household is used to distinguish the organizational behaviour of firms. Firms produce satisfaction to groups as traditional managerial and early behavioural theories of the firm of Williamson, Baumol and Marris suggest, as well as more modern principle agent models. Under certain conditions, intra-firm bargaining leads to a Pareto optimal outcome. What makes this work an important contribution is that it identifies a set of nonvacuous testable restrictions to empirically detect if firm-level data satisfy Pareto optimal behaviour for the main decision makers in the organization.     

Economic class and the distribution of income: a time-series analysis of the UK economy, 1955–2010

This paper contributes to our understanding of the determinants and dynamics of surplus-value using quarterly UK data, 1955–2010, and the Johansen (1988 Johansen, S. 1988. Statistical analysis of cointegrated vectors. Journal of Economic Dynamic and Control, 12: 231–54. [Crossref], [Web of Science ®] , [Google Scholar], 1991 Johansen, S. 1991. Estimation and hypothesis of cointegration vectors in Gaussian vector autoregressive models. Econometrica, 59: 1551–80. [Crossref], [Web of Science ®] , [Google Scholar]) cointegration and vector error correction model (VECM). A model is introduced to define this Marxian concept, before we explain distribution, paying attention to three forces that are traditionally seen as drivers of power in this struggle: (i) working class militancy; (ii) the size of the ‘reserve army’ of the unemployed; and (iii) political party. Our results demonstrate the ongoing relevance of Marxian economics in providing an alternative, robust and significant explanation of distribution in the post-war UK economy.     

Comparisons of robust tests for shifts in trend with an application to trend deviations of real exchange rates in the long run

We study the finite sample properties of tests for structural changes in the trend function of a time series that do not require knowledge of the degree of persistence in the noise component. The tests of interest are the quasi-Feasible Generalized Least Squares (FGLS) procedure by Perron and Yabu (2009b Perron, P and Yabu, T. 2009b. Testing for shifts in trend with an integrated or stationary noise component. Journal of Business and Economic Statistics, 27: 369–96. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) and the weighted average of the regression t-statistics by Harvey et al. (2009 Harvey, DI, Leybourne, SJ and Taylor, AMR. 2009. Simple, robust, and powerful tests of the breaking trend hypothesis. Econometric Theory, 25: 995–1029. [Crossref], [Web of Science ®] , [Google Scholar]), both of which have the same limit distribution whether the noise component is stationary or has a unit-root. We analyse the finite sample size and power properties of these tests under a variety of Data-Generating Processes (DGPs). The results show that the Perron–Yabu test has greater power overall. With respect to the size, the Harvey–Leybourne–Taylor test exhibits larger size distortions unless a moving-average component is present. Using the Perron and Yabu procedure to test for structural changes in the trend function of long-run real exchange rates with respect to the US dollar indicates that for 17 out of 19 countries, the series have experienced a shift in trend since the late nineteenth century.     

Ownership herding and informational herding

This article takes as its point of departure the herding model of Bikhchandani et al. (1992 Bikhchandani, S., Hirshleifer, D. and Welch, I. 1992. A theory of fads, fashion, custom, and cultural change as informational cascades. Journal of Political Economy, 100: 992–1026. [Crossref], [Web of Science ®] , [Google Scholar]). We extend earlier experimental evidence to distinguish between informational herding, as in the model, and ownership herding, an alternative explanation for observed behaviour.