While theory of autoregressive conditional heteroskedasticity (ARCH) models is well understood for strictly stationary processes, some recent interest has focused on the nonstationary case. In the classical model including a positive intercept parameter, the volatility process diverges to...

A novel procedure is applied to test for switches between hysteresis and the natural rate theory over more than a century of UK and USA unemployment data. For both the countries we see a period conforming to hysteresis starting in the early 1920s for the UK and 1930 for USA.

This paper studies issues related to the estimation of a structural change in the persistence of a univariate time series. The break is such that the process has a unit root [i.e., is I(1)] in the pre-break regime but reverts to a stationary [i.e., I(0)] process in the post-break regime or vice...

We show that the use of generalized least squares (GLS-)detrending procedures with bound-specific non-centrality parameter leads to important empirical power gains compared to using the ordinary least squares (OLS-)detrending method when testing the null hypothesis of unit root for bounded...

We study the stationarity of consumption–income ratio (APC) in OECD countries. To that end, we use three different bootstrapping techniques to construct the 90% confidence intervals. The results show that the APC is non-stationary in most of the countries.

We suggest a new unit-root test with a Fourier function in the deterministic term in a Dickey–Fuller type regression framework. Our suggested test can complement the Fourier LM and DF-GLS unit root tests. They have good size and power properties.

We present empirical evidence regarding the structure of unemployment in the US disaggregated by race, ethnicity, and gender. Popp’s (2008) unit-root test reveals that the dynamics of unemployment for all groups is characterized by the hysteresis hypothesis except for Hispanic Males.

We examine the performance of nonlinear instrumental variable (NIV) unit root tests using various recursive detrending methods. We find that the NIV unit root tests using the recursive detrending method of Chang (2002) are the most powerful. They are more powerful than OLS based DF tests.