A momentum-threshold autoregressive unit root test with increased power

Recent research has shown the momentum-threshold autoregressive (MTAR) unit root test of Enders and Granger (J. Business Econom. Statist. 16 (1998) 304) to exhibit less power than modified Dickey-Fuller tests when applied to MTAR processes. In this paper a revised MTAR test is proposed which employs local-to-unity detrending. The newly proposed test is shown to possess greater power than both the original MTAR test and modified Dickey-Fuller tests over a range of MTAR processes.