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.

The use of recursive demeaning and detrending procedures in unit root tests has been popular in the literature, since they lead to more precise estimation of the persistence parameter and greater power in unit root tests. However, we find that unit root tests using these recursive procedures...

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.

We build on the threshold unit root tests in Enders and Granger (1998) and develop tests based on Lagrange Multiplier (LM) unit root tests. The asymptotic properties are derived and finite sample properties are examined in simulations.