矛盾的慧根 发表于 2012-3-22 15:36 
忘了,你自己查一下
你对原来的序列做单位根检验了吗?
嗯,做过,如下:
Exogenous: Constant
Lag Length: 3 (Automatic based on AIC, MAXLAG=19)
t-Statistic Prob.*
Augmented Dickey-Fuller test statistic -2.322571 0.1651
Test critical values: 1% level -3.439411
5% level -2.865429
10% level -2.568897
*MacKinnon (1996) one-sided p-values.
Augmented Dickey-Fuller Test Equation
Dependent Variable: D(PRICE)
Method: Least Squares
Date: 03/22/12 Time: 15:49
Sample (adjusted): 1/09/2009 11/30/2011
Included observations: 704 after adjustments
Variable Coefficient Std. Error t-Statistic Prob.
PRICE(-1) -0.008591 0.003699 -2.322571 0.0205
D(PRICE(-1)) -0.014597 0.037434 -0.389953 0.6967
D(PRICE(-2)) -0.076442 0.037313 -2.048691 0.0409
D(PRICE(-3)) 0.064206 0.037368 1.718209 0.0862
C 138.9772 57.64035 2.411109 0.0162
R-squared 0.018424 Mean dependent var 5.617898
Adjusted R-squared 0.012807 S.D. dependent var 151.4628
S.E. of regression 150.4898 Akaike info criterion 12.87274
Sum squared resid 15830370 Schwarz criterion 12.90511
Log likelihood -4526.206 Hannan-Quinn criter. 12.88525
F-statistic 3.280055 Durbin-Watson stat 1.979551
Prob(F-statistic) 0.011192