LM Tests for Joint Breaks in the Dynamics and Level of a Long-Memory Time Series
长记忆时间序列动态与水平联合突变的 LM 检验
We consider a single-step Lagrange multiplier (LM) test for joint breaks (at known or unknown dates) in the long memory parameter, the short-run dynamics, and the level of a fractionally integrated time-series process. The regression version of this test is easily implementable and allows to identify the specific sources of the break when the null hypothesis of parameter stability is rejected. However, its size and power properties are sensitive to the correct specification…