Multiple Trend Breaks and the Unit-Root Hypothesis
在单位根检验中允许两个内生断点，发现比Zivot和Andrews（允许一个断点）更多证据反对单位根假说，但比Perron（外生断点）更少。
Ever since Nelson and Plosser (1982) found evidence in favor of the unit-root hypothesis for 13 long-term annual macro series, observed unit - root behavior has been equated with persistence in the economy. Perron (1989) questioned this interpretation, arguing instead that the "observed" behavior may indicate failure to account for structural change. Zivot and Andrews (1992) restored confidence in the unit-root hypothesis by incorporating an endogenous break point into the specification. By allowing for the possibility of two endogenous break points, we find more evidence against the unit-root hypothesis than Zivot and Andrews, but less than Perron. © 1997 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology