The two-break unit root test of Lumsdaine and Papell (1997) is examined and found to suffer from bias and spurious rejections in the presence of structural breaks under the null. A two-break minimum LM unit root test is proposed as a remedy. The two-break LM test does not suffer from bias and spurious rejections and is mostly invariant to the size, location, and misspecification of the breaks. ...

While there is good reason to expect crude oil production to be non-linear, previous studies that have examined the stochastic properties of crude oil production have assumed that crude oil production follows a linear process. If crude oil production is a non-linear process, conventional unit root tests, which assume linear and systematic adjustment, could interpret departure from linearity as ...

A nonparametric, residual-based block bootstrap procedure is proposed in the context of testing for integrated (unit root) time series. The resampling procedure is based on weak assumptions on the dependence structure of the stationary process driving the random walk and successfully generates unit root integrated pseudo-series retaining the important characteristics of the data. It is more gen...

In this paper the asymptotic properties of ARMA processes with complex-conjugate unit roots in the AR lag polynomial are studied. These processes behave quite di¤erently from regular unit root processes (with a single root equal to 1). In particular, the asymptotic properties of a standardized version of the periodogram for such processes are analyzed, and a nonparametric test of the complex un...

This paper analyzes the mean reversion and unit root properties of general diffusion models and their discrete samples. In particular, we find that the Dickey-Fuller unit root test applied to discrete samples from a diffusion model becomes a test of no mean reversion rather than a unit root, or more generally, nonstationarity in the underlying diffusion. The unit root test has a well defined li...

The Phillips-Perron unit root test was used to test for unit roots, using level or trend nonstationarity as the null [1]. (A unit root tests whether a variable y evolves as a random walk, i.e., with the dynamic relation yt = yt-1 + constant + deterministic trend + errort.) The KPSS test [1,2], which uses level or trend stationarity as the null, was used to confirm the results of the Phillips-Pe...