We Consider the Null Hypothesis That a Time Series Has a Unit Root with Possibly Non-Zero Drift Against the Alternative That the Process Is 'Trend-Stationary'. the Interest Is That We Allow Under Both the Null and Alternative Hypotheses for the Presence of a One-Time Change in the Level Or in...

Many unit root and cointegration tests require an estimate of the spectral density function at frequency zero at some process. Kernel estimators based on weighted sums of autocovariances constructed using estimated residuals from an AR(1) regression are commonly used. However, it is known that...