目的:1、正确使用EVIEWS
2、会使用OLS和WLS,Goldfeld-Quandt检验
3、能根据计算结果进行异方差分析和出现异方差性后的补救。
3、数据为demo data1
实例:某市人均储蓄与人均收入的关系分析(异方差性检验及补救)
根据某市1978-1998年人均储蓄与人均收入的数据资料(见下表),其中X为人均收入(元),Y为人均储蓄(元),经分析人均储蓄受人均收入的线性影响,可建立一元线性回归模型进行分析。
obs | X | Y |
1978 | 590.2000 | 107.0000 |
1979 | 664.9400 | 123.0000 |
1980 | 809.5000 | 159.0000 |
1981 | 875.5400 | 189.0000 |
1982 | 991.2500 | 233.0000 |
1983 | 1109.950 | 312.0000 |
1984 | 1357.870 | 401.0000 |
1985 | 1682.800 | 522.0000 |
1986 | 1890.580 | 664.0000 |
1987 | 2098.250 | 871.0000 |
1988 | 2499.580 | 1033.000 |
1989 | 2827.730 | 1589.000 |
1990 | 3084.170 | 2209.000 |
1991 | 3462.710 | 2878.000 |
1992 | 3932.520 | 3722.000 |
1993 | 5150.790 | 5350.000 |
1994 | 7153.350 | 8080.000 |
1995 | 9076.850 | 11758.00 |
1996 | 10448.21 | 15839.00 |
1997 | 11575.48 | 18196.00 |
1998 | 12500.84 | 20954.00 |
1、用OLS估计法估计参数
设模型为:

运行EVIEWS软件,并输入数据,得计算结果如下:
Dependent Variable: Y |
Method: Least Squares |
Date: 10/11/05 Time: 23:10 |
Sample: 1978 1998 |
Included observations: 21 |
Variable | Coefficient | Std. Error | t-Statistic | Prob. |
C | -2185.998 | 339.9020 | -6.431262 | 0.0000 |
X | 1.684158 | 0.062166 | 27.09150 | 0.0000 |
R-squared | 0.974766 | Mean dependent var | 4533.238 |
Adjusted R-squared | 0.973438 | S.D. dependent var | 6535.103 |
S.E. of regression | 1065.086 | Akaike info criterion | 16.86989 |
Sum squared resid | 21553736 | Schwarz criterion | 16.96937 |
Log likelihood | -175.1338 | F-statistic | 733.9495 |
Durbin-Watson stat | 0.293421 | Prob(F-statistic) | 0.000000 |
2、异方差检验
(1)Goldfeld-Quandt检验
在Procs菜单项选Sort series项,出现排序对话框,输入X,OK。
在Sample菜单里,将时间定义为1978-1985,用OLS方法计算得如下结果:
Y = -145.441495 + 0.3971185479*X
(-8.730234) (25.42693)
R-squared=0.990805 Sum squared resid1=15.12284
Dependent Variable: Y |
Method: Least Squares |
Date: 10/11/05 Time: 23:25 |
Sample: 1978 1985 |
Included observations: 8 |
Variable | Coefficient | Std. Error | t-Statistic | Prob. |
C | -145.4415 | 16.65952 | -8.730234 | 0.0001 |
X | 0.397119 | 0.015618 | 25.42693 | 0.0000 |
R-squared | 0.990805 | Mean dependent var | 255.7500 |
Adjusted R-squared | 0.989273 | S.D. dependent var | 146.0105 |
S.E. of regression | 15.12284 | Akaike info criterion | 8.482607 |
Sum squared resid | 1372.202 | Schwarz criterion | 8.502468 |
Log likelihood | -31.93043 | F-statistic | 646.5287 |
Durbin-Watson stat | 1.335534 | Prob(F-statistic) | 0.000000 |
在Sample菜单里,将时间定义为1991-1998,用OLS方法计算得如下结果:
Y = -4602.367144 + 1.952519317*X
(-5.065962) (18.40942)
R-squared=0.982604 Sum squared resid2=5811189.
Dependent Variable: Y | |
Method: Least Squares | |
Date: 10/11/05 Time: 23:29 | |
Sample: 1991 1998 | |
Included observations: 8 | |
Variable | Coefficient | Std. Error | t-Statistic | Prob. |
C | -4602.367 | 908.4882 | -5.065962 | 0.0023 |
X | 1.952519 | 0.106061 | 18.40942 | 0.0000 |
R-squared | 0.982604 | Mean dependent var | 10847.12 |
Adjusted R-squared | 0.979705 | S.D. dependent var | 6908.102 |
S.E. of regression | 984.1400 | Akaike info criterion | 16.83373 |
Sum squared resid | 5811189. | Schwarz criterion | 16.85359 |
Log likelihood | -65.33492 | F-statistic | 338.9068 |
Durbin-Watson stat | 0.837367 | Prob(F-statistic) | 0.000002 |
求F统计量:
,查F分布表,给定显著性水平
,得临界值
,比较
>
,拒绝原假设
,表明随机误差项显著的存在异方差。
3、异方差的修正
(1)WLS估计法。
首先生成权函数
,然后用OLS估计参数,
Y = -2262.639946 + 1.566910934*X
Dependent Variable: Y |
Method: Least Squares |
Date: 10/12/05 Time: 08:07 |
Sample: 1978 1998 |
Included observations: 21 |
Weighting series: W |
Variable | Coefficient | Std. Error | t-Statistic | Prob. |
C | -2262.640 | 131.2507 | -17.23907 | 0.0000 |
X | 1.566911 | 0.057637 | 27.18590 | 0.0000 |
Weighted Statistics | | | | |
R-squared | 0.961501 | Mean dependent var | 2183.201 |
Adjusted R-squared | 0.959475 | S.D. dependent var | 2104.209 |
S.E. of regression | 423.5951 | Akaike info criterion | 15.02583 |
Sum squared resid | 3409224. | Schwarz criterion | 15.12530 |
Log likelihood | -155.7712 | F-statistic | 474.5211 |
Durbin-Watson stat | 0.354490 | Prob(F-statistic) | 0.000000 |
Unweighted Statistics | | | | |
R-squared | 0.962755 | Mean dependent var | 4533.238 |
Adjusted R-squared | 0.960794 | S.D. dependent var | 6535.103 | |
S.E. of regression | 1293.978 | Sum squared resid | 31813191 | |
Durbin-Watson stat | 0.224165 | | | |
(2)对数变换法。
用GENR生成LY和LX序列,用OLS方法求LY 对LX的回归,结果如下:
LY = -6.839135503 + 1.787148637*LX
Dependent Variable: LY |
Method: Least Squares |
Date: 10/12/05 Time: 00:05 |
Sample: 1978 1998 |
Included observations: 21 |
Variable | Coefficient | Std. Error | t-Statistic | Prob. |
C | -6.839136 | 0.237565 | -28.78845 | 0.0000 |
LX | 1.787149 | 0.030033 | 59.50680 | 0.0000 |
R-squared | 0.994663 | Mean dependent var | 7.195082 |
Adjusted R-squared | 0.994382 | S.D. dependent var | 1.746173 |
S.E. of regression | 0.130880 | Akaike info criterion | -1.138677 |
Sum squared resid | 0.325463 | Schwarz criterion | -1.039199 |
Log likelihood | 13.95611 | F-statistic | 3541.059 |
Durbin-Watson stat | 0.642916 | Prob(F-statistic) | 0.000000 |
比较方法(1)和(2),可以看出X与Y在对数线性回归下拟合效果较好。原因是Y的曲线呈对数型图形有关。
