crystal8832 发表于 2015-6-4 17:18
不是只能包含三阶,而是当存在高阶时一般采用GARCH(1,1)以节省自由度
只含三阶Heteroskedasticity Test: ARCH
F-statistic 2.979231 Prob. F(4,111) 0.0222
Obs*R-squared 11.24632 Prob. Chi-Square(4) 0.0239
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 06/05/15 Time: 08:50
Sample (adjusted): 6 121
Included observations: 116 after adjustments
Variable Coefficient Std. Error t-Statistic Prob.
C 0.605152 0.212651 2.845757 0.0053
WGT_RESID^2(-1) -0.073373 0.093146 -0.787729 0.4325
WGT_RESID^2(-2) 0.081397 0.090920 0.895254 0.3726
WGT_RESID^2(-3) 0.216513 0.090764 2.385460 0.0188
WGT_RESID^2(-4) 0.208094 0.092836 2.241527 0.0270
R-squared 0.096951 Mean dependent var 1.038763
Adjusted R-squared 0.064409 S.D. dependent var 1.487865
S.E. of regression 1.439151 Akaike info criterion 3.608131
Sum squared resid 229.8984 Schwarz criterion 3.726820
Log likelihood -204.2716 Hannan-Quinn criter. 3.656312
F-statistic 2.979231 Durbin-Watson stat 2.010581
Prob(F-statistic) 0.022225