Discussion Papers, Interdisciplinary Research Project 373: Quantification and Simulation of Economic Processes 2001,5
A number of unit root tests which accommodate a deterministic level shift at a known point in time are compared in a Monte Carlo study. The tests differ in the way they treat the deterministic term of the DGP. It turns out that Phillips-Perron type tests have very poor small sample properties and cannot be recommended for applied work. Moreover, tests which estimate the deterministic term by a GLS procedure under the unit root null hypothesis are superior in terms of size and power properties relative to tests which estimate the deterministic term by OLS procedures.
Univariate time series unit root structural shift autoregression