统计研究 ›› 2010, Vol. 27 ›› Issue (2): 98-106.

• 论文 • 上一篇    下一篇

门限自回归下的单位根检验可靠性研究

刘汉中   

  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2010-02-15 发布日期:2010-02-15

Study on the Reliability of Unit Root Tests in Threshold Autoregressive Models

Liu Hanzhong

  

  • Received:1900-01-01 Revised:1900-01-01 Online:2010-02-15 Published:2010-02-15

摘要: 在非对称的门限自回归模型下,由于传统单位根检验式的误设,会导致单位根检验势下降。本文通过一系列的Monte-Carlo模拟表明:非对称性对ADF和PP检验的检验势会产生较大影响,而对其他四种常用的单位根检验势产生的影响较小,也就是说,在非对称的门限自回归下,非对称性对退势单位根检验势产生的影响较小。模拟中也发现:NP单位根检验对TAR模型和持久性都具有稳健性。

关键词: 门限自回归, 单位根检验, 检验势, MC模拟

Abstract: It is widely known that test power is reduced owing to the specification error of test equation while in testing the unit root hypothesis against a threshold autoregressive model(TAR) as the alternative. By means of a Monte Carlo study, the paper investigates the performance of six popular unit root tests against a TAR model. Our simulation results show that the asymmetry of TAR makes a great impact on test power of ADF and PP tests, and however, makes a small impact on test power of the other unit root tests. That is to say, unit root tests based on detrending to data process are more powerful for TAR models. In addition, simulation results reveal that NP test has robust property while against a TAR model.

Key words: Threshold Autoregressive Model, Unit root test, Test power, Monte-Carlo Simulation