我用EVIEWS6对一个序列做单位根检验,结果如下:
Null Hypothesis: SER01 has a unit root
Exogenous: Constant
Lag Length: 0 (Automatic based on SIC, MAXLAG=10)
t-Statistic Prob.*
Augmented Dickey-Fuller test statistic -5.456468 0.0000
Test critical values: 1% level -3.574446
5% level -2.923780
10% level -2.599925
*MacKinnon (1996) one-sided p-values.
Augmented Dickey-Fuller Test Equation
Dependent Variable: D(SER01)
Method: Least Squares
Date: 08/03/11 Time: 21:55
Sample (adjusted): 2 49
Included observations: 48 after adjustments
Coefficient Std. Error t-Statistic Prob.
SER01(-1) -0.781615 0.143246 -5.456468 0.0000
C 7664.857 1673.990 4.578794 0.0000
R-squared 0.392924 Mean dependent var -99.22917
Adjusted R-squared 0.379727 S.D. dependent var 7757.035
S.E. of regression 6109.242 Akaike info criterion 20.31377
Sum squared resid 1.72E+09 Schwarz criterion 20.39173
Log likelihood -485.5304 Hannan-Quinn criter. 20.34323
F-statistic 29.77304 Durbin-Watson stat 1.933489
Prob(F-statistic) 0.000002
滞后期的选择默认用了SIC准则检验,而且默认最大滞后期为10,结果如上所示,ADF小于临界值说明是平稳的,但是AIC和SC值太大了吧,一般是多少正常呢。我把默认最大滞后期改成1、2、3等试了结果是一样的。肯定高手指点!!!!!