In this study, we propose a new unit root test procedure that allows for both gradual structural break and asymmetric nonlinear adjustment towards the equilibrium level. Small-sample properties of the new test are examined through Monte-Carlo simulations. The simulation results suggest that the...

We develop unit root tests that allow under the alternative hypothesis for a smooth transition between deterministic linear trends, around which stationary asymmetric adjustment may occur by employing exponential smooth transition auto-regressive (ESTAR) models The small sample properties of the...