In this paper we derive tests for parameter constancy when the data generating process is non-stationary against the hypothesis that the parameters of the model change smoothly over time. To obtain the asymptotic distributions of the tests we generalize many theoretical results, as well as new...

This research points to the serious problem of potentially misspecified alternative hypotheses when testing for unit roots in real exchange rates. We apply a popular unit root test against nonlinear ESTAR and develop a Markov Switching unit root test. The empirical power of these tests against...

This paper proposes a version of the DF-GLS test that incorporates up to two breaks in the intercept, namely the DF-GLSTB test. While the asymptotic properties of the DF-GLS test remain valid, the presence of changes in the intercept has an impact on the small sample properties of the test....

Methods of inference based on a unit root assumption in the data are typically not robust to even small deviations from this assumption. In this paper, we propose robust procedures for a residual-based test of cointegration when the data are generated by a near unit root process. A Bonferroni...

The random coefficient autoregressive model has been utilized for modeling financial time series because it possesses features that are often observed in financial time series. When the mean of the random autoregressive coefficient is one, it is called the stochastic unit root model. This paper...

A unit root test is proposed for time series with a nonparametric trend component using a pooled regression of overlapping blocks. The class of trend functions considered includes any boundedly differentiable trend function with finitely many breaks. Limiting null-distributions of the pseudo...

In this paper we propose tests based on GLS-detrending for testing the null hypothesis of deterministic seasonality. Unlike existing tests for deterministic seasonality, our tests do not suff er from asymptotic size distortions under near integration. We also investigate the behavior of the...

In a recently publicized study, Harvey et al. (2012) investigated procedures for unit root testing employing break detection methods under local break in trend. We apply this methodology to analyze asymptotic and nite sample behavior of procedures under local break to test the stationarity null...