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.     

Do shale gas and oil productions move in convergence? An investigation using unit root tests with structural breaks

This paper investigates the long-run trends of shale gas and shale oil productions by applying univariate and panel Lagrange Multiplier (LM), GARCH-based, and PANICCA unit root tests to discover the mean-reverting behaviors. We employ monthly data from January 2007 to December 2016 of shale gas withdrawals and shale oil productions in the U.S. The empirical results both on specific state/oil well and panel data show that most structural breaks emerge around 2007–2011, during which shale energy was massively produced in the U.S. and the global financial crisis and energy shock occurred. Our results also indicate that most external shocks are transitory and the trends soon converge, and that cross-state/well factors have greater potential as temporary shocks than the state-specific/well-particular components. For robust analysis, we conduct additional LM tests of natural gas and crude oil productions for a comparison with the unconventional shale energy. The unit root test of Narayan and Popp (2010) on shale gas and shale oil productions help us to find more stationary evidence. Overall, we present powerful findings of the mean-reversion property and propose critical implications for authorities and market participants.     

Is there a unit root in the inflation rate? New evidence from panel data models with multiple structural breaks

In this article, we examine whether or not the inflation rate for 17 OECD countries can be modelled as a stationary process. We find that (1) conventional univariate unit root tests without any structural breaks generally reveal that the inflation rate contains a unit root; (2) the KPSS univariate test with multiple structural breaks reveals that for 10 out of 17 countries inflation is stationary; and (3) the KPSS panel unit root test reveals strong evidence for stationarity of the inflation rate for panels consisting of countries which were declared nonstationary by univariate tests.     

Do Malaysian house prices follow a random walk? Evidence from univariate and panel LM unit root tests with one and two structural breaks

In this article we apply univariate and panel Lagrange Multiplier (LM) unit root tests with one and twostructural breaks proposed by Lee and Strazicich (2003, 2004) and Im et al. (2005) to examine housing prices for five different housing price indices (all housing, detached housing, semi-detached housing, terrace housing and high-rise housing) in 14 states of Malaysia to test whether housing prices exhibit a random walk. Our main finding from the univariate LM unit root tests is that for the vast majority of states housing prices follow a stationary process about a segmented trend. The results of the panel LM unit root tests provide overwhelming evidence that house prices are segmented trend reverting.