第二章 简单线性回归模型
2.1
(1) ①首先分析人均寿命与人均GDP的数量关系,用Eviews分析:
Dependent Variable: Y
Method: Least Squares
Date: 12/23/15 Time: 14:37
Sample: 1 22
Included observations: 22
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
56.64794
1.960820
28.88992
0.0000
X1
0.128360
0.027242
4.711834
0.0001
R-squared
0.526082
Mean dependent var
62.50000
Adjusted R-squared
0.502386
S.D. dependent var
10.08889
S.E. of regression
7.116881
Akaike info criterion
6.849324
Sum squared resid
1013.000
Schwarz criterion
6.948510
Log likelihood
-73.34257
Hannan-Quinn criter.
6.872689
F-statistic
22.20138
Durbin-Watson stat
0.629074
Prob(F-statistic)
0.000134
有上可知,关系式为y=56.64794+0.128360x1
②关于人均寿命与成人识字率的关系,用Eviews分析如下:
Dependent Variable: Y
Method: Least Squares
Date: 12/23/15 Time: 15:01
Sample: 1 22
Included observations: 22
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
38.79424
3.532079
10.98340
0.0000
X2
0.331971
0.046656
7.115308
0.0000
R-squared
0.716825
Mean dependent var
62.50000
Adjusted R-squared
0.702666
S.D. dependent var
10.08889
S.E. of regression
5.501306
Akaike info criterion
6.334356
Sum squared resid
605.2873
Schwarz criterion
6.433542
Log likelihood
-67.67792
Hannan-Quinn criter.
6.357721
F-statistic
50.62761
Durbin-Watson stat
1.846406
Prob(F-statistic)
0.000001
由上可知,关系式为y=38.79424+0.331971x2
③关于人均寿命与一岁儿童疫苗接种率的关系,用Eviews分析如下:
Dependent Variable: Y
Method: Least Squares
Date: 12/23/14 Time: 15:20
Sample: 1 22
Included observations: 22
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
31.79956
6.536434
4.864971
0.0001
X3
0.387276
0.080260
4.825285
0.0001
R-squared
0.537929
Mean dependent var
62.50000
Adjusted R-squared
0.514825
S.D. dependent var
10.08889
S.E. of regression
7.027364
Akaike info criterion
6.824009
Sum squared resid
987.6770
Schwarz criterion
6.923194
Log likelihood
-73.06409
Hannan-Quinn criter.
6.847374
F-statistic
23.28338
Durbin-Watson stat
0.952555
Prob(F-statistic)
0.000103
由上可知,关系式为y=31.79956+0.387276x3
(2)①关于人均寿命与人均GDP模型,由上可知,可决系数为0.526082,说明所建模型整体上对样本数据拟合较好。
对于回归系数的t检验:t(β1)=4.711834>t0.025(20)=2.086,对斜率系数的显著性检验
表
关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf
明,人均GDP对人均寿命有显著影响。
②关于人均寿命与成人识字率模型,由上可知,可决系数为0.716825,说明所建模型整体上对样本数据拟合较好。
对于回归系数的t检验:t(β2)=7.115308>t0.025(20)=2.086,对斜率系数的显著性检验表明,成人识字率对人均寿命有显著影响。
③关于人均寿命与一岁儿童疫苗的模型,由上可知,可决系数为0.537929,说明所建模型整体上对样本数据拟合较好。
对于回归系数的t检验:t(β3)=4.825285>t0.025(20)=2.086,对斜率系数的显著性检验表明,一岁儿童疫苗接种率对人均寿命有显著影响。
2.2
(1)
①对于浙江省预算收入与全省生产总值的模型,用Eviews分析结果如下:
Dependent Variable: Y
Method: Least Squares
Date: 12/23/15 Time: 17:46
Sample (adjusted): 1 33
Included observations: 33 after adjustments
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.176124
0.004072
43.25639
0.0000
C
-154.3063
39.08196
-3.948274
0.0004
R-squared
0.983702
Mean dependent var
902.5148
Adjusted R-squared
0.983177
S.D. dependent var
1351.009
S.E. of regression
175.2325
Akaike info criterion
13.22880
Sum squared resid
951899.7
Schwarz criterion
13.31949
Log likelihood
-216.2751
Hannan-Quinn criter.
13.25931
F-statistic
1871.115
Durbin-Watson stat
0.100021
Prob(F-statistic)
0.000000
②由上可知,模型的参数:斜率系数0.176124,截距为—154.3063
③关于浙江省财政预算收入与全省生产总值的模型,检验模型的显著性:
1)可决系数为0.983702,说明所建模型整体上对样本数据拟合较好。
2)对于回归系数的t检验:t(β2)=43.25639>t0.025(31)=2.0395,对斜率系数的显著性检验表明,全省生产总值对财政预算总收入有显著影响。
④用规范形式写出检验结果如下:
Y=0.176124X—154.3063
(0.004072) (39.08196)
t= (43.25639) (-3.948274)
R2=0.983702 F=1871.115 n=33
⑤经济意义是:全省生产总值每增加1亿元,财政预算总收入增加0.176124亿元。
(2)当x=32000时,
①进行点预测,由上可知Y=0.176124X—154.3063,代入可得:
Y= Y=0.176124*32000—154.3063=5481.6617
②进行区间预测:
先由Eviews分析:
X
Y
Mean
6000.441
902.5148
Median
2689.280
209.3900
Maximum
27722.31
4895.410
Minimum
123.7200
25.87000
Std. Dev.
7608.021
1351.009
Skewness
1.432519
1.663108
Kurtosis
4.010515
4.590432
Jarque-Bera
12.69068
18.69063
Probability
0.001755
0.000087
Sum
198014.5
29782.99
Sum Sq. Dev.
1.85E+09
58407195
Observations
33
33
由上表可知,
∑x2=∑(Xi—X)2=δ2x(n—1)= 7608.0212 x (33—1)=1852223.473
(Xf—X)2=(32000— 6000.441)2=675977068.2
当Xf=32000时,将相关数据代入计算得到:
5481.6617—2.0395x175.2325x√1/33+1852223.473/675977068.2≤
Yf≤5481.6617+2.0395x175.2325x√1/33+1852223.473/675977068.2
即Yf的置信区间为(5481.6617—64.9649, 5481.6617+64.9649)
(3) 对于浙江省预算收入对数与全省生产总值对数的模型,由Eviews分析结果如下:
Dependent Variable: LNY
Method: Least Squares
Date: 12/23/15 Time: 18:04
Sample (adjusted): 1 33
Included observations: 33 after adjustments
Variable
Coefficient
Std. Error
t-Statistic
Prob.
LNX
0.980275
0.034296
28.58268
0.0000
C
-1.918289
0.268213
-7.152121
0.0000
R-squared
0.963442
Mean dependent var
5.573120
Adjusted R-squared
0.962263
S.D. dependent var
1.684189
S.E. of regression
0.327172
Akaike info criterion
0.662028
Sum squared resid
3.318281
Schwarz criterion
0.752726
Log likelihood
-8.923468
Hannan-Quinn criter.
0.692545
F-statistic
816.9699
Durbin-Watson stat
0.096208
Prob(F-statistic)
0.000000
①模型方程为:lnY=0.980275lnX-1.918289
②由上可知,模型的参数:斜率系数为0.980275,截距为-1.918289
③关于浙江省财政预算收入与全省生产总值的模型,检验其显著性:
1)可决系数为0.963442,说明所建模型整体上对样本数据拟合较好。
2)对于回归系数的t检验:t(β2)=28.58268>t0.025(31)=2.0395,对斜率系数的显著性检验表明,全省生产总值对财政预算总收入有显著影响。
④经济意义:全省生产总值每增长1%,财政预算总收入增长0.980275%
2.4
(1)对建筑面积与建造单位成本模型,用Eviews分析结果如下:
Dependent Variable: Y
Method: Least Squares
Date: 12/23/15 Time: 20:11
Sample: 1 12
Included observations: 12
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
-64.18400
4.809828
-13.34434
0.0000
C
1845.475
19.26446
95.79688
0.0000
R-squared
0.946829
Mean dependent var
1619.333
Adjusted R-squared
0.941512
S.D. dependent var
131.2252
S.E. of regression
31.73600
Akaike info criterion
9.903792
Sum squared resid
10071.74
Schwarz criterion
9.984610
Log likelihood
-57.42275
Hannan-Quinn criter.
9.873871
F-statistic
178.0715
Durbin-Watson stat
1.172407
Prob(F-statistic)
0.000000
由上可得:建筑面积与建造成本的回归方程为:
Y=1845.475--64.18400X
(2)经济意义:建筑面积每增加1万平方米,建筑单位成本每平方米减少64.18400元。
(3)
①首先进行点预测,由Y=1845.475--64.18400X得,当x=4.5,y=1556.647
②再进行区间估计:
用Eviews分析:
Y
X
Mean
1619.333
3.523333
Median
1630.000
3.715000
Maximum
1860.000
6.230000
Minimum
1419.000
0.600000
Std. Dev.
131.2252
1.989419
Skewness
0.003403
-0.060130
Kurtosis
2.346511
1.664917
Jarque-Bera
0.213547
0.898454
Probability
0.898729
0.638121
Sum
19432.00
42.28000
Sum Sq. Dev.
189420.7
43.53567
Observations
12
12
由上表可知,
∑x2=∑(Xi—X)2=δ2x(n—1)= 1.9894192 x (12—1)=43.5357
(Xf—X)2=(4.5— 3.523333)2=0.95387843
当Xf=4.5时,将相关数据代入计算得到:
1556.647—2.228x31.73600x√1/12+43.5357/0.95387843≤
Yf≤1556.647+2.228x31.73600x√1/12+43.5357/0.95387843
即Yf的置信区间为(1556.647—478.1231, 1556.647+478.1231)
3.1
(1)
①对百户拥有家用汽车量计量经济模型,用Eviews分析结果如下:
Dependent Variable: Y
Method: Least Squares
Date: 12/23/15 Time: 20:59
Sample: 1 31
Included observations: 31
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X2
5.996865
1.406058
4.265020
0.0002
X3
-0.524027
0.179280
-2.922950
0.0069
X4
-2.265680
0.518837
-4.366842
0.0002
C
246.8540
51.97500
4.749476
0.0001
R-squared
0.666062
Mean dependent var
16.77355
Adjusted R-squared
0.628957
S.D. dependent var
8.252535
S.E. of regression
5.026889
Akaike info criterion
6.187394
Sum squared resid
682.2795
Schwarz criterion
6.372424
Log likelihood
-91.90460
Hannan-Quinn criter.
6.247709
F-statistic
17.95108
Durbin-Watson stat
1.147253
Prob(F-statistic)
0.000001
②得到模型得:
Y=246.8540+5.996865X2- 0.524027 X3-2.265680 X4
③对模型进行检验:
1) 可决系数是0.666062,修正的可决系数为0.628957,说明模型对样本拟合较好
2) F检验,F=17.95108>F(3,27)=3.65,回归方程显著。
3)t检验,t统计量分别为4.749476,4.265020,-2.922950,-4.366842,均大于
t(27)=2.0518,所以这些系数都是显著的。
④依据:
1) 可决系数越大,说明拟合程度越好
2) F的值与临界值比较,若大于临界值,则否定原假设,回归方程是显著的;若小于临界值,则接受原假设,回归方程不显著。
3) t的值与临界值比较,若大于临界值,则否定原假设,系数都是显著的;若小于临界值,则接受原假设,系数不显著。
(2)经济意义:人均GDP增加1万元,百户拥有家用汽车增加5.996865辆,城镇人口比重增加1个百分点,百户拥有家用汽车减少0.524027辆,交通工具消费价格指数每上升1,百户拥有家用汽车减少2.265680辆。
(3)用EViews分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/23/15 Time: 21:09
Sample: 1 31
Included observations: 31
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X2
5.135670
1.010270
5.083465
0.0000
LNX3
-22.81005
6.771820
-3.368378
0.0023
LNX4
-230.8481
49.46791
-4.666624
0.0001
C
1148.758
228.2917
5.031974
0.0000
R-squared
0.691952
Mean dependent var
16.77355
Adjusted R-squared
0.657725
S.D. dependent var
8.252535
S.E. of regression
4.828088
Akaike info criterion
6.106692
Sum squared resid
629.3818
Schwarz criterion
6.291723
Log likelihood
-90.65373
Hannan-Quinn criter.
6.167008
F-statistic
20.21624
Durbin-Watson stat
1.150090
Prob(F-statistic)
0.000000
模型方程为:
Y=5.135670 X2-22.81005 LNX3-230.8481 LNX4+1148.758
此分析得出的可决系数为0.691952>0.666062,拟合程度得到了提高,可这样改进。
3.2
(1)对出口货物总额计量经济模型,用Eviews分析结果如下::
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 08:23
Sample: 1994 2011
Included observations: 18
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X2
0.135474
0.012799
10.58454
0.0000
X3
18.85348
9.776181
1.928512
0.0729
C
-18231.58
8638.216
-2.110573
0.0520
R-squared
0.985838
Mean dependent var
6619.191
Adjusted R-squared
0.983950
S.D. dependent var
5767.152
S.E. of regression
730.6306
Akaike info criterion
16.17670
Sum squared resid
8007316.
Schwarz criterion
16.32510
Log likelihood
-142.5903
Hannan-Quinn criter.
16.19717
F-statistic
522.0976
Durbin-Watson stat
1.173432
Prob(F-statistic)
0.000000
①由上可知,模型为:
Y = 0.135474X2 + 18.85348X3 - 18231.58
②对模型进行检验:
1)可决系数是0.985838,修正的可决系数为0.983950,说明模型对样本拟合较好
2)F检验,F=522.0976>F(2,15)=4.77,回归方程显著
3)t检验,t统计量分别为X2的系数对应t值为10.58454,大于t(15)=2.131,系数是显著的,X3的系数对应t值为1.928512,小于t(15)=2.131,说明此系数是不显著的。
(2)对于对数模型,用Eviews分析结果如下:
Dependent Variable: LNY
Method: Least Squares
Date: 12/24/15 Time: 08:47
Sample: 1994 2011
Included observations: 18
Variable
Coefficient
Std. Error
t-Statistic
Prob.
LNX2
1.564221
0.088988
17.57789
0.0000
LNX3
1.760695
0.682115
2.581229
0.0209
C
-20.52048
5.432487
-3.777363
0.0018
R-squared
0.986295
Mean dependent var
8.400112
Adjusted R-squared
0.984467
S.D. dependent var
0.941530
S.E. of regression
0.117343
Akaike info criterion
-1.296424
Sum squared resid
0.206540
Schwarz criterion
-1.148029
Log likelihood
14.66782
Hannan-Quinn criter.
-1.275962
F-statistic
539.7364
Durbin-Watson stat
0.686656
Prob(F-statistic)
0.000000
①由上可知,模型为:
LNY=-20.52048+1.564221 LNX2+1.760695 LNX3
②对模型进行检验:
1)可决系数是0.986295,修正的可决系数为0.984467,说明模型对样本拟合较好。
2)F检验,F=539.7364> F(2,15)=4.77,回归方程显著。
3)t检验,t统计量分别为-3.777363,17.57789,2.581229,均大于t(15)=2.131,所以这些系数都是显著的。
(3)
①(1)式中的经济意义:工业增加1亿元,出口货物总额增加0.135474亿元,人民币汇率增加1,出口货物总额增加18.85348亿元。
②(2)式中的经济意义:工业增加额每增加1%,出口货物总额增加1.564221%,人民币汇率每增加1%,出口货物总额增加1.760695%
3.3
(1)对家庭书刊消费对家庭月平均收入和户主受教育年数计量模型,由Eviews分析结果如下:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 09:03
Sample: 1 18
Included observations: 18
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.086450
0.029363
2.944186
0.0101
T
52.37031
5.202167
10.06702
0.0000
C
-50.01638
49.46026
-1.011244
0.3279
R-squared
0.951235
Mean dependent var
755.1222
Adjusted R-squared
0.944732
S.D. dependent var
258.7206
S.E. of regression
60.82273
Akaike info criterion
11.20482
Sum squared resid
55491.07
Schwarz criterion
11.35321
Log likelihood
-97.84334
Hannan-Quinn criter.
11.22528
F-statistic
146.2974
Durbin-Watson stat
2.605783
Prob(F-statistic)
0.000000
①模型为:Y = 0.086450X + 52.37031T-50.01638
②对模型进行检验:
1)可决系数是0.951235,修正的可决系数为0.944732,说明模型对样本拟合较好。
2)F检验,F=539.7364> F(2,15)=4.77,回归方程显著。
3)t检验,t统计量分别为2.944186,10.06702,均大于t(15)=2.131,所以这些系数都是显著的。
③经济意义:家庭月平均收入增加1元,家庭书刊年消费支出增加0.086450元,户主受教育年数增加1年,家庭书刊年消费支出增加52.37031元。
(2)用Eviews分析:
①
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 09:18
Sample: 1 18
Included observations: 18
Variable
Coefficient
Std. Error
t-Statistic
Prob.
T
63.01676
4.548581
13.85416
0.0000
C
-11.58171
58.02290
-0.199606
0.8443
R-squared
0.923054
Mean dependent var
755.1222
Adjusted R-squared
0.918245
S.D. dependent var
258.7206
S.E. of regression
73.97565
Akaike info criterion
11.54979
Sum squared resid
87558.36
Schwarz criterion
11.64872
Log likelihood
-101.9481
Hannan-Quinn criter.
11.56343
F-statistic
191.9377
Durbin-Watson stat
2.134043
Prob(F-statistic)
0.000000
②
Dependent Variable: X
Method: Least Squares
Date: 12/24/15 Time: 09:34
Sample: 1 18
Included observations: 18
Variable
Coefficient
Std. Error
t-Statistic
Prob.
T
123.1516
31.84150
3.867644
0.0014
C
444.5888
406.1786
1.094565
0.2899
R-squared
0.483182
Mean dependent var
1942.933
Adjusted R-squared
0.450881
S.D. dependent var
698.8325
S.E. of regression
517.8529
Akaike info criterion
15.44170
Sum squared resid
4290746.
Schwarz criterion
15.54063
Log likelihood
-136.9753
Hannan-Quinn criter.
15.45534
F-statistic
14.95867
Durbin-Watson stat
1.052251
Prob(F-statistic)
0.001364
以上分别是y与T,X与T的一元回归
模型分别是:
Y = 63.01676T - 11.58171
X = 123.1516T + 444.5888
(3)对残差进行模型分析,用Eviews分析结果如下:
Dependent Variable: E1
Method: Least Squares
Date: 12/24/15 Time: 09:39
Sample: 1 18
Included observations: 18
Variable
Coefficient
Std. Error
t-Statistic
Prob.
E2
0.086450
0.028431
3.040742
0.0078
C
3.96E-14
13.88083
2.85E-15
1.0000
R-squared
0.366239
Mean dependent var
2.30E-14
Adjusted R-squared
0.326629
S.D. dependent var
71.76693
S.E. of regression
58.89136
Akaike info criterion
11.09370
Sum squared resid
55491.07
Schwarz criterion
11.19264
Log likelihood
-97.84334
Hannan-Quinn criter.
11.10735
F-statistic
9.246111
Durbin-Watson stat
2.605783
Prob(F-statistic)
0.007788
模型为:
E1 = 0.086450E2 + 3.96e-14
参数:斜率系数α为0.086450,截距为3.96e-14
(3)由上可知,β2与α2的系数是一样的。回归系数与被解释变量的残差系数是一样的,它们的变化规律是一致的。
3.6
(1)预期的符号是X1,X2,X3,X4,X5的符号为正,X6的符号为负
(2)根据Eviews分析得到数据如下:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 10:13
Sample: 1994 2011
Included observations: 18
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X2
0.001382
0.001102
1.254330
0.2336
X3
0.001942
0.003960
0.490501
0.6326
X4
-3.579090
3.559949
-1.005377
0.3346
X5
0.004791
0.005034
0.951671
0.3600
X6
0.045542
0.095552
0.476621
0.6422
C
-13.77732
15.73366
-0.875659
0.3984
R-squared
0.994869
Mean dependent var
12.76667
Adjusted R-squared
0.992731
S.D. dependent var
9.746631
S.E. of regression
0.830963
Akaike info criterion
2.728738
Sum squared resid
8.285993
Schwarz criterion
3.025529
Log likelihood
-18.55865
Hannan-Quinn criter.
2.769662
F-statistic
465.3617
Durbin-Watson stat
1.553294
Prob(F-statistic)
0.000000
①与预期不相符。
②评价:
1) 可决系数为0.994869,数据相当大,可以认为拟合程度很好。
2) F检验,F=465.3617>F(5.12)=3,89,回归方程显著
3) T检验,X1,X2,X3,X4,X5,X6 系数对应的t值分别为:1.254330,0.490501,-1.005377,0.951671,0.476621,均小于t(12)=2.179,所以所得系数都是不显著的。
(3)根据Eviews分析得到数据如下:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 10:20
Sample: 1994 2011
Included observations: 18
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X5
0.001032
2.20E-05
46.79946
0.0000
X6
-0.054965
0.031184
-1.762581
0.0983
C
4.205481
3.335602
1.260786
0.2266
R-squared
0.993601
Mean dependent var
12.76667
Adjusted R-squared
0.992748
S.D. dependent var
9.746631
S.E. of regression
0.830018
Akaike info criterion
2.616274
Sum squared resid
10.33396
Schwarz criterion
2.764669
Log likelihood
-20.54646
Hannan-Quinn criter.
2.636736
F-statistic
1164.567
Durbin-Watson stat
1.341880
Prob(F-statistic)
0.000000
①得到模型的方程为:
Y=0.001032 X5-0.054965 X6+4.205481
②评价:
1) 可决系数为0.993601,数据相当大,可以认为拟合程度很好。
2) F检验,F=1164.567>F(5.12)=3,89,回归方程显著
3) T检验,X5 系数对应的t值为46.79946,大于t(12)=2.179,所以系数是显著的,即人均GDP对年底存款余额有显著影响。 X6 系数对应的t值为-1.762581,小于t(12)=2.179,所以系数是不显著的。
4.3
(1)根据Eviews分析得到数据如下:
Dependent Variable: LNY
Method: Least Squares
Date: 12/24/15 Time: 10:39
Sample: 1985 2011
Included observations: 27
Variable
Coefficient
Std. Error
t-Statistic
Prob.
LNGDP
1.338533
0.088610
15.10582
0.0000
LNCPI
-0.421791
0.233295
-1.807975
0.0832
C
-3.111486
0.463010
-6.720126
0.0000
R-squared
0.988051
Mean dependent var
9.484710
Adjusted R-squared
0.987055
S.D. dependent var
1.425517
S.E. of regression
0.162189
Akaike info criterion
-0.695670
Sum squared resid
0.631326
Schwarz criterion
-0.551689
Log likelihood
12.39155
Hannan-Quinn criter.
-0.652857
F-statistic
992.2582
Durbin-Watson stat
0.522613
Prob(F-statistic)
0.000000
得到的模型方程为:
LNY=1.338533 LNGDPt-0.421791 LNCPIt-3.111486
(2)
1 该模型的可决系数为0.988051,可决系数很高,F检验值为992.2582,
明显显著。但当α=0.05时,t(24)=2.064,LNCPI的系数不显著,可能存在多重共线性。
②得到相关系数矩阵如下:
LNY
LNGDP
LNCPI
LNY
1.000000
0.993189
0.935116
LNGDP
0.993189
1.000000
0.953740
LNCPI
0.935116
0.953740
1.000000
LNGDP, LNCPI之间的相关系数很高,证实确实存在多重共线性。
(3)由Eviews得:
a)
Dependent Variable: LNY
Method: Least Squares
Date: 12/24/15 Time: 10:41
Sample: 1985 2011
Included observations: 27
Variable
Coefficient
Std. Error
t-Statistic
Prob.
LNGDP
1.185739
0.027822
42.61933
C
-3.750670
0.312255
-12.01156
0.0000
R-squared
0.986423
Mean dependent var
9.484710
Adjusted R-squared
0.985880
S.D. dependent var
1.425517
S.E. of regression
0.169389
Akaike info criterion
-0.642056
Sum squared resid
0.717312
Schwarz criterion
-0.546068
Log likelihood
10.66776
Hannan-Quinn criter.
-0.613514
F-statistic
1816.407
Durbin-Watson stat
0.471111
Prob(F-statistic)
0.000000
b)
Dependent Variable: LNY
Method: Least Squares
Date: 12/24/15 Time: 10:55
Sample: 1985 2011
Included observations: 27
Variable
Coefficient
Std. Error
t-Statistic
Prob.
LNCPI
2.939295
0.222756
13.19511
0.0000
C
-6.854535
1.242243
-5.517871
0.0000
R-squared
0.874442
Mean dependent var
9.484710
Adjusted R-squared
0.869419
S.D. dependent var
1.425517
S.E. of regression
0.515124
Akaike info criterion
1.582368
Sum squared resid
6.633810
Schwarz criterion
1.678356
Log likelihood
-19.36196
Hannan-Quinn criter.
1.610910
F-statistic
174.1108
Durbin-Watson stat
0.137042
Prob(F-statistic)
0.000000
c)
Dependent Variable: LNGDP
Method: Least Squares
Date: 12/24/15 Time: 11:07
Sample: 1985 2011
Included observations: 27
Variable
Coefficient
Std. Error
t-Statistic
Prob.
LNCPI
2.511022
0.158302
15.86227
0.0000
C
-2.796381
0.882798
-3.167634
0.0040
R-squared
0.909621
Mean dependent var
11.16214
Adjusted R-squared
0.906005
S.D. dependent var
1.194029
S.E. of regression
0.366072
Akaike info criterion
0.899213
Sum squared resid
3.350216
Schwarz criterion
0.995201
Log likelihood
-10.13938
Hannan-Quinn criter.
0.927755
F-statistic
251.6117
Durbin-Watson stat
0.099623
Prob(F-statistic)
0.000000
①得到的回归方程分别为
1)LNY=1.185739 LNGDPt-3.750670
2)LNY=2.939295 LNCPIt-6.854535
3)LNGDPt=2.511022 LNCPIt-2.796381
②对多重共线性的认识:
单方程拟合效果都很好,回归系数显著,判定系数较高,GDP和CPI对进口的显著的单一影响,在这两个变量同时引入模型时影响方向发生了改变,这只有通过相关系数的分析才能发现。
(4)建议:如果仅仅是作预测,可以不在意这种多重共线性,但如果是进行结构分析,还是应该引起注意的。
4.4
(1)按照设计的理论模型,由Eviews分析得:
Dependent Variable: CZSR
Method: Least Squares
Date: 12/24/15 Time: 11:23
Sample: 1985 2011
Included observations: 27
Variable
Coefficient
Std. Error
t-Statistic
Prob.
CZZC
0.090114
0.044367
2.031129
0.0540
GDP
-0.025334
0.005069
-4.998036
0.0000
SSZE
1.176894
0.062162
18.93271
0.0000
C
-221.8540
130.6532
-1.698038
0.1030
R-squared
0.999857
Mean dependent var
22572.56
Adjusted R-squared
0.999838
S.D. dependent var
27739.49
S.E. of regression
353.0540
Akaike info criterion
14.70707
Sum squared resid
2866884.
Schwarz criterion
14.89905
Log likelihood
-194.5455
Hannan-Quinn criter.
14.76416
F-statistic
53493.93
Durbin-Watson stat
1.458128
Prob(F-statistic)
0.000000
从回归结果可见,可决系数为0.999857,校正的可决系数为0.999838,模型拟合的很好。F的统计量为53493.93,说明在α=0.05,水平下,回归方程回归方程整体上是显著的。但是t检验结果表明,国内生产总值对财政收入的影响显著,但回归系数的符号为负,与实际不符合。由此可得知,该方程可能存在多重共线性。
(2)得到相关系数矩阵如下:
CZSR
CZZC
GDP
SSZE
CZSR
1.000000
0.998729
0.992838
0.999832
CZZC
0.998729
1.000000
0.992536
0.998575
GDP
0.992838
0.992536
1.000000
0.994370
SSZE
0.999832
0.998575
0.994370
1.000000
由上表可知,CZZC与GDP,CZZC与SSZE,GDP与SSZE之间的相关系数都非常高,说明确实存在多重共线性。
(3)做辅助回归
被解释变量
可决系数
方差扩大因子
CZZC
0.997168
353
GDP
0.988833
90
SSZE
0.997862
468
方差扩大因子均大于10,存在严重多重共线性。并且通过以上分析,两两被解释变量之间相关性都很高。
(4)解决方式:分别作出财政收入与财政支出、国内生产总值、税收总额之间的一元回归。
5.2
(1)
①用图形法检验
绘制e2的散点图,用Eviews分析如下:
由上图可知,模型可能存在异方差,
2 Goldfeld-Quanadt检验
1)定义区间为1-7时,由软件分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 14:52
Sample: 1 7
Included observations: 7
Variable
Coefficient
Std. Error
t-Statistic
Prob.
T
35.20664
4.901492
7.182843
0.0020
X
0.109949
0.061965
1.774380
0.1507
C
77.12588
82.32844
0.936807
0.4019
R-squared
0.943099
Mean dependent var
565.6857
Adjusted R-squared
0.914649
S.D. dependent var
108.2755
S.E. of regression
31.63265
Akaike info criterion
10.04378
Sum squared resid
4002.499
Schwarz criterion
10.02060
Log likelihood
-32.15324
Hannan-Quinn criter.
9.757267
F-statistic
33.14880
Durbin-Watson stat
1.426262
Prob(F-statistic)
0.003238
得∑e1i2=4002.499
2)定义区间为12-18时,由软件分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 14:55
Sample: 12 18
Included observations: 7
Variable
Coefficient
Std. Error
t-Statistic
Prob.
T
52.40588
6.923378
7.569409
0.0016
X
0.068689
0.053763
1.277635
0.2705
C
-8.789265
79.92542
-0.109968
0.9177
R-squared
0.984688
Mean dependent var
887.6143
Adjusted R-squared
0.977032
S.D. dependent var
274.4148
S.E. of regression
41.58810
Akaike info criterion
10.59103
Sum squared resid
6918.280
Schwarz criterion
10.56785
Log likelihood
-34.06861
Hannan-Quinn criter.
10.30451
F-statistic
128.6166
Durbin-Watson stat
2.390329
Prob(F-statistic)
0.000234
得∑e2i2=6918.280
3)根据Goldfeld-Quanadt检验,F统计量为:
F=∑e2i2 /∑e1i2 =6918.280/4002.499=1.7285
在α=0.05水平下,分子分母的自由度均为4,查分布表得临界值F0.05(4,4)=6.39,因为F=1.7285< F0.05(4,4)=6.39,所以接受原假设,此检验表明模型不存在异方差。
(2)存在异方差,估计参数的方法:
①可以对模型进行变换
②使用加权最小二乘法进行计算,得出模型方程,并对其进行相关检验
③对模型进行对数变换,进行分析
(3)评价:
3.3所得结论是可以相信的,随机扰动项之间不存在异方差。回归方程是显著的。
5.3
(1)由Eviews软件分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 16:00
Sample: 1 31
Included observations: 31
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
1.244281
0.079032
15.74411
0.0000
C
242.4488
291.1940
0.832602
0.4119
R-squared
0.895260
Mean dependent var
4443.526
Adjusted R-squared
0.891649
S.D. dependent var
1972.072
S.E. of regression
649.1426
Akaike info criterion
15.85152
Sum squared resid
12220196
Schwarz criterion
15.94404
Log likelihood
-243.6986
Hannan-Quinn criter.
15.88168
F-statistic
247.8769
Durbin-Watson stat
1.078581
Prob(F-statistic)
0.000000
由上表可知,2007年我国农村居民家庭人均消费支出(x)对人均纯收入(y)的模型为:
Y=1.244281X+242.4488
(2)
①由图形法检验
由上图可知,模型可能存在异方差。
②Goldfeld-Quanadt检验
1)定义区间为1-12时,由软件分析得:
Dependent Variable: Y1
Method: Least Squares
Date: 12/24/15 Time: 16:05
Sample: 1 12
Included observations: 12
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X1
1.485296
0.500386
2.968297
0.0141
C
-550.5492
1220.063
-0.451247
0.6614
R-squared
0.468390
Mean dependent var
3052.950
Adjusted R-squared
0.415229
S.D. dependent var
550.5148
S.E. of regression
420.9803
Akaike info criterion
15.07406
Sum squared resid
1772245.
Schwarz criterion
15.15488
Log likelihood
-88.44437
Hannan-Quinn criter.
15.04414
F-statistic
8.810789
Durbin-Watson stat
2.354167
Prob(F-statistic)
0.014087
得∑e1i2=1772245.
2)定义区间为20-31时,由软件分析得:
Dependent Variable: Y1
Method: Least Squares
Date: 12/24/15 Time: 16:16
Sample: 20 31
Included observations: 12
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X1
1.086940
0.148863
7.301623
0.0000
C
1173.307
733.2520
1.600141
0.1407
R-squared
0.842056
Mean dependent var
6188.329
Adjusted R-squared
0.826262
S.D. dependent var
2133.692
S.E. of regression
889.3633
Akaike info criterion
16.56990
Sum squared resid
7909670.
Schwarz criterion
16.65072
Log likelihood
-97.41940
Hannan-Quinn criter.
16.53998
F-statistic
53.31370
Durbin-Watson stat
2.339767
Prob(F-statistic)
0.000026
得∑e2i2=7909670.
3)根据Goldfeld-Quanadt检验,F统计量为:
F=∑e2i2 /∑e1i2 =7909670./ 1772245=4.4631
在α=0.05水平下,分子分母的自由度均为10,查分布表得临界值F0.05(10,10)=2.98,因为F=4.4631> F0.05(10,10)=2.98,所以拒绝原假设,此检验表明模型存在异方差。
(3)
1)采用WLS法估计过程中,
①用权数w1=1/X,建立回归得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 16:29
Sample: 1 31
Included observations: 31
Weighting series: W1
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
1.425859
0.119104
11.97157
0.0000
C
-334.8131
344.3523
-0.972298
0.3389
Weighted Statistics
R-squared
0.831707
Mean dependent var
3946.082
Adjusted R-squared
0.825904
S.D. dependent var
536.1907
S.E. of regression
536.6796
Akaike info criterion
15.47102
Sum squared resid
8352726.
Schwarz criterion
15.56354
Log likelihood
-237.8008
Hannan-Quinn criter.
15.50118
F-statistic
143.3184
Durbin-Watson stat
1.369081
Prob(F-statistic)
0.000000
Unweighted Statistics
R-squared
0.875855
Mean dependent var
4443.526
Adjusted R-squared
0.871574
S.D. dependent var
1972.072
S.E. of regression
706.7236
Sum squared resid
14484289
Durbin-Watson stat
1.532908
对此模型进行White检验得:
Heteroskedasticity Test: White
F-statistic
0.299395
Prob. F(2,28)
0.7436
Obs*R-squared
0.649065
Prob. Chi-Square(2)
0.7229
Scaled explained SS
1.798067
Prob. Chi-Square(2)
0.4070
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 12/24/15 Time: 16:34
Sample: 1 31
Included observations: 31
Collinear test regressors dropped from specification
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
61927.89
1045682.
0.059222
0.9532
WGT^2
-593927.9
1173622.
-0.506064
0.6168
X*WGT^2
282.4407
747.9780
0.377606
0.7086
R-squared
0.020938
Mean dependent var
269442.8
Adjusted R-squared
-0.048995
S.D. dependent var
689166.5
S.E. of regression
705847.6
Akaike info criterion
29.86395
Sum squared resid
1.40E+13
Schwarz criterion
30.00273
Log likelihood
-459.8913
Hannan-Quinn criter.
29.90919
F-statistic
0.299395
Durbin-Watson stat
1.922336
Prob(F-statistic)
0.743610
从上可知,nR2=0.649065,比较计算的统计量的临界值,因为nR2=0.649065<0.05(2)=5.9915,所以接受原假设,该模型消除了异方差。
估计结果为:
Y=1.425859X-334.8131
t=(11.97157)(-0.972298)
R2=0.875855 F=143.3184 DW=1.369081
②用权数w2=1/x2,用回归分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 16:40
Sample: 1 31
Included observations: 31
Weighting series: W2
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
1.557040
0.145392
10.70922
0.0000
C
-693.1946
376.4760
-1.841272
0.0758
Weighted Statistics
R-squared
0.798173
Mean dependent var
3635.028
Adjusted R-squared
0.791214
S.D. dependent var
1029.830
S.E. of regression
466.8513
Akaike info criterion
15.19224
Sum squared resid
6320554.
Schwarz criterion
15.28475
Log likelihood
-233.4797
Hannan-Quinn criter.
15.22240
F-statistic
114.6875
Durbin-Watson stat
1.562975
Prob(F-statistic)
0.000000
Unweighted Statistics
R-squared
0.834850
Mean dependent var
4443.526
Adjusted R-squared
0.829156
S.D. dependent var
1972.072
S.E. of regression
815.1229
Sum squared resid
19268334
Durbin-Watson stat
1.678365
对此模型进行White检验得:
Heteroskedasticity Test: White
F-statistic
0.299790
Prob. F(3,27)
0.8252
Obs*R-squared
0.999322
Prob. Chi-Square(3)
0.8014
Scaled explained SS
1.789507
Prob. Chi-Square(3)
0.6172
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 12/24/15 Time: 16:45
Sample: 1 31
Included observations: 31
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
-111661.8
549855.7
-0.203075
0.8406
WGT^2
426220.2
2240181.
0.190262
0.8505
X^2*WGT^2
0.194888
0.516395
0.377402
0.7088
X*WGT^2
-583.2151
2082.820
-0.280012
0.7816
R-squared
0.032236
Mean dependent var
203888.8
Adjusted R-squared
-0.075293
S.D. dependent var
419282.0
S.E. of regression
434780.1
Akaike info criterion
28.92298
Sum squared resid
5.10E+12
Schwarz criterion
29.10801
Log likelihood
-444.3062
Hannan-Quinn criter.
28.98330
F-statistic
0.299790
Durbin-Watson stat
1.835854
Prob(F-statistic)
0.825233
从上可知,nR2=0.999322,比较计算的统计量的临界值,因为nR2=0.999322<0.05(2)=5.9915,所以接受原假设,该模型消除了异方差。
估计结果为:
Y=1.557040X-693.1946
t=(10.70922)(-1.841272)
R2=0.798173 F=114.6875 DW=1.562975
③用权数w3=1/sqr(x),用回归分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 16:49
Sample: 1 31
Included observations: 31
Weighting series: W3
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
1.330130
0.098345
13.52507
0.0000
C
-47.40242
313.1154
-0.151390
0.8807
Weighted Statistics
R-squared
0.863161
Mean dependent var
4164.118
Adjusted R-squared
0.858442
S.D. dependent var
991.2079
S.E. of regression
586.9555
Akaike info criterion
15.65012
Sum squared resid
9990985.
Schwarz criterion
15.74263
Log likelihood
-240.5768
Hannan-Quinn criter.
15.68027
F-statistic
182.9276
Durbin-Watson stat
1.237664
Prob(F-statistic)
0.000000
Unweighted Statistics
R-squared
0.890999
Mean dependent var
4443.526
Adjusted R-squared
0.887240
S.D. dependent var
1972.072
S.E. of regression
662.2171
Sum squared resid
12717412
Durbin-Watson stat
1.314859
对此模型进行White检验得:
Heteroskedasticity Test: White
F-statistic
0.423886
Prob. F(2,28)
0.6586
Obs*R-squared
0.911022
Prob. Chi-Square(2)
0.6341
Scaled explained SS
2.768332
Prob. Chi-Square(2)
0.2505
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 12/24/15 Time: 16:57
Sample: 1 31
Included observations: 31
Collinear test regressors dropped from specification
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
1212308.
2141958.
0.565981
0.5759
WGT^2
-715673.0
1301839.
-0.549740
0.5869
X^2*WGT^2
-0.015194
0.082276
-0.184677
0.8548
R-squared
0.029388
Mean dependent var
322289.8
Adjusted R-squared
-0.039942
S.D. dependent var
863356.7
S.E. of regression
880429.8
Akaike info criterion
30.30597
Sum squared resid
2.17E+13
Schwarz criterion
30.44475
Log likelihood
-466.7426
Hannan-Quinn criter.
30.35121
F-statistic
0.423886
Durbin-Watson stat
1.887426
Prob(F-statistic)
0.658628
从上可知,nR2=0.911022,比较计算的统计量的临界值,因为nR2=0.911022<0.05(2)=5.9915,所以接受原假设,该模型消除了异方差。
估计结果为:
Y=1.330130X-47.40242
t=(13.52507)(-0.151390)
R2=0.863161 F=182.9276 DW=1.237664
经过检验发现,用权数w1的效果最好,所以综上可知,即修改后的结果为:
Y=1.425859X-334.8131
t=(11.97157)(-0.972298)
R2=0.875855 F=143.3184 DW=1.369081
5.6
(1)
a)用Eviews模型分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 19:16
Sample: 1978 2011
Included observations: 34
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.746241
0.019120
39.03027
0.0000
C
92.55422
42.80529
2.162215
0.0382
R-squared
0.979426
Mean dependent var
1295.802
Adjusted R-squared
0.978783
S.D. dependent var
1188.791
S.E. of regression
173.1597
Akaike info criterion
13.20333
Sum squared resid
959497.2
Schwarz criterion
13.29311
Log likelihood
-222.4566
Hannan-Quinn criter.
13.23395
F-statistic
1523.362
Durbin-Watson stat
1.534491
Prob(F-statistic)
0.000000
得回归模型为:
Y=0.746241 X+92.55422
b)检验是否存在异方差:
①用Goldfeld-Quanadt检验如下:
1)当定义区间为1-13时,由软件分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 19:27
Sample: 1 13
Included observations: 13
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.967839
0.026879
36.00771
0.0000
C
-18.86861
8.963780
-2.104984
0.0591
R-squared
0.991587
Mean dependent var
280.1377
Adjusted R-squared
0.990823
S.D. dependent var
127.0409
S.E. of regression
12.17039
Akaike info criterion
7.976527
Sum squared resid
1629.301
Schwarz criterion
8.063442
Log likelihood
-49.84742
Hannan-Quinn criter.
7.958662
F-statistic
1296.555
Durbin-Watson stat
1.071505
Prob(F-statistic)
0.000000
得∑e1i2=1629.301
2)当定义区间为1-13时,由软件分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 19:34
Sample: 22 34
Included observations: 13
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.719567
0.058312
12.33998
0.0000
C
179.3950
202.8764
0.884258
0.3955
R-squared
0.932629
Mean dependent var
2496.127
Adjusted R-squared
0.926504
S.D. dependent var
1022.591
S.E. of regression
277.2250
Akaike info criterion
14.22817
Sum squared resid
845390.4
Schwarz criterion
14.31509
Log likelihood
-90.48313
Hannan-Quinn criter.
14.21031
F-statistic
152.2752
Durbin-Watson stat
1.658418
Prob(F-statistic)
0.000000
得∑e2i2=845390.4
3)根据Goldfeld-Quanadt检验,F统计量为:
F=∑e2i2 /∑e1i2 =845390.4/ 1629.301=518.8669
在α=0.05水平下,分子分母的自由度均为11,查分布表得临界值F0.05(11,11)=4.47,因为F=518.8669> F0.05(11,11)=4.47,所以拒绝原假设,此检验表明模型存在异方差。
②White检验
用EViews软件分析得:
Heteroskedasticity Test: White
F-statistic
10.36759
Prob. F(2,31)
0.0004
Obs*R-squared
13.62701
Prob. Chi-Square(2)
0.0011
Scaled explained SS
76.13635
Prob. Chi-Square(2)
0.0000
Test Equation:
Dependent Variable: RESID^2
Method: Least Squares
Date: 12/24/15 Time: 19:56
Sample: 1 34
Included observations: 34
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
11581.11
26117.11
0.443430
0.6605
X
-27.69901
27.86540
-0.994029
0.3279
X^2
0.012230
0.005156
2.371861
0.0241
R-squared
0.400795
Mean dependent var
28220.51
Adjusted R-squared
0.362136
S.D. dependent var
101738.9
S.E. of regression
81255.15
Akaike info criterion
25.53267
Sum squared resid
2.05E+11
Schwarz criterion
25.66735
Log likelihood
-431.0554
Hannan-Quinn criter.
25.57860
F-statistic
10.36759
Durbin-Watson stat
3.021651
Prob(F-statistic)
0.000357
从上图中可以看出,nR2=13.62701,比较计算的统计量的临界值,因为nR2=13.62701>0.05(2)=5.9915,所以拒绝原假设,不拒绝备择假设,表明模型存在异方差。
用以上两种方法,可以检验模型是存在异方差的。
c)修正模型
1)用加权二乘法修正异方差现象步骤如下:
①当权数w1=1/x时,用软件分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 20:22
Sample: 1 34
Included observations: 34
Weighting series: W1
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.821013
0.016866
48.67993
0.0000
C
17.69318
6.283256
2.815926
0.0083
Weighted Statistics
R-squared
0.986676
Mean dependent var
457.8505
Adjusted R-squared
0.986260
S.D. dependent var
41.70384
S.E. of regression
37.91285
Akaike info criterion
10.16548
Sum squared resid
45996.29
Schwarz criterion
10.25527
Log likelihood
-170.8132
Hannan-Quinn criter.
10.19610
F-statistic
2369.735
Durbin-Watson stat
0.605852
Prob(F-statistic)
0.000000
Unweighted Statistics
R-squared
0.968070
Mean dependent var
1295.802
Adjusted R-squared
0.967072
S.D. dependent var
1188.791
S.E. of regression
215.7175
Sum squared resid
1489089.
Durbin-Watson stat
1.079107
得方程模型为:
Y=0.821013X-17.69318
t=(48.67993)(2.815926)
R2=0.986676 F=2369.735 DW=0.605852
对此模型进行White检验如下:
Heteroskedasticity Test: White
F-statistic
1.348072
Prob. F(2,31)
0.2745
Obs*R-squared
2.720457
Prob. Chi-Square(2)
0.2566
Scaled explained SS
1.221901
Prob. Chi-Square(2)
0.5428
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 12/24/15 Time: 20:29
Sample: 1 34
Included observations: 34
Collinear test regressors dropped from specification
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
1678.870
416.5417
4.030498
0.0003
WGT^2
-32.13071
187.6175
-0.171257
0.8651
X*WGT^2
-0.484040
1.279449
-0.378319
0.7078
R-squared
0.080013
Mean dependent var
1352.832
Adjusted R-squared
0.020659
S.D. dependent var
1382.825
S.E. of regression
1368.467
Akaike info criterion
17.36487
Sum squared resid
58053732
Schwarz criterion
17.49955
Log likelihood
-292.2027
Hannan-Quinn criter.
17.41080
F-statistic
1.348072
Durbin-Watson stat
1.199640
Prob(F-statistic)
0.274545
从上图中可以看出,nR2=2.720457,比较计算的统计量的临界值,
因为nR2=2.720457<0.05(2)=5.9915,所以接受原假设,即该模型消除了异方差的影响。
②当权数w2=1/x2时,用软件分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 20:41
Sample: 1 34
Included observations: 34
Weighting series: W2
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.852193
0.020150
42.29335
0.0000
C
8.890886
3.604301
2.466744
0.0192
Weighted Statistics
R-squared
0.982425
Mean dependent var
230.2433
Adjusted R-squared
0.981875
S.D. dependent var
247.1718
S.E. of regression
16.20273
Akaike info criterion
8.465259
Sum squared resid
8400.912
Schwarz criterion
8.555045
Log likelihood
-141.9094
Hannan-Quinn criter.
8.495879
F-statistic
1788.728
Durbin-Watson stat
0.604647
Prob(F-statistic)
0.000000
Unweighted Statistics
R-squared
0.954142
Mean dependent var
1295.802
Adjusted R-squared
0.952709
S.D. dependent var
1188.791
S.E. of regression
258.5207
Sum squared resid
2138654.
Durbin-Watson stat
0.781788
得方程模型为:
Y=0.852193X+8.890886
t=(42.29335)(2.466744)
R2=0.982425 F=1788.728 DW=0.604647
用White检验模型得:
Heteroskedasticity Test: White
F-statistic
7.462185
Prob. F(3,30)
0.0007
Obs*R-squared
14.52935
Prob. Chi-Square(3)
0.0023
Scaled explained SS
19.40139
Prob. Chi-Square(3)
0.0002
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 12/24/15 Time: 20:55
Sample: 1 34
Included observations: 34
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
-7.684700
85.76169
-0.089605
0.9292
WGT^2
64.20016
96.11160
0.667975
0.5093
X^2*WGT^2
0.006306
0.003431
1.838317
0.0759
X*WGT^2
-1.247222
1.163558
-1.071903
0.2923
R-squared
0.427334
Mean dependent var
247.0857
Adjusted R-squared
0.370067
S.D. dependent var
435.4791
S.E. of regression
345.6323
Akaike info criterion
14.63876
Sum squared resid
3583851.
Schwarz criterion
14.81833
Log likelihood
-244.8589
Hannan-Quinn criter.
14.70000
F-statistic
7.462185
Durbin-Watson stat
1.586012
Prob(F-statistic)
0.000712
从上图中可以看出,nR2=14.52935,比较计算的统计量的临界值,因为nR2=14.52935>0.05(2)=5.9915,所以拒绝原假设,不拒绝备择假设,表明模型存在异方差。此模型并未消除异方差。
③当权数w3=1/sqr(x)时,用软件分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 21:06
Sample: 1 34
Included observations: 34
Weighting series: W3
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.778551
0.015677
49.66347
0.0000
C
40.45770
14.57528
2.775775
0.0091
Weighted Statistics
R-squared
0.987192
Mean dependent var
776.3266
Adjusted R-squared
0.986792
S.D. dependent var
367.3152
S.E. of regression
79.19828
Akaike info criterion
11.63881
Sum squared resid
200715.8
Schwarz criterion
11.72859
Log likelihood
-195.8597
Hannan-Quinn criter.
11.66943
F-statistic
2466.460
Durbin-Watson stat
1.178340
Prob(F-statistic)
0.000000
Unweighted Statistics
R-squared
0.977590
Mean dependent var
1295.802
Adjusted R-squared
0.976890
S.D. dependent var
1188.791
S.E. of regression
180.7210
Sum squared resid
1045123.
Durbin-Watson stat
1.460832
得方程模型为:
Y=0.778551X+40.45770
t=(49.66347)(2.775775)
R2=0.986792 F=2466.460 DW=1.178340
对所得模型进行White检验:
Heteroskedasticity Test: White
F-statistic
8.158958
Prob. F(2,31)
0.0014
Obs*R-squared
11.72514
Prob. Chi-Square(2)
0.0028
Scaled explained SS
28.08353
Prob. Chi-Square(2)
0.0000
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 12/24/15 Time: 21:23
Sample: 1 34
Included observations: 34
Collinear test regressors dropped from specification
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
-7585.186
5311.263
-1.428132
0.1633
WGT^2
2468.369
1996.041
1.236632
0.2255
X^2*WGT^2
0.009139
0.002481
3.684177
0.0009
R-squared
0.344857
Mean dependent var
5903.405
Adjusted R-squared
0.302590
S.D. dependent var
13934.64
S.E. of regression
11636.97
Akaike info criterion
21.64586
Sum squared resid
4.20E+09
Schwarz criterion
21.78054
Log likelihood
-364.9796
Hannan-Quinn criter.
21.69179
F-statistic
8.158958
Durbin-Watson stat
2.344068
Prob(F-statistic)
0.001423
从上图中可以看出,nR2=11.72514,比较计算的统计量的临界值,因为nR2=11.72514>0.05(2)=5.9915,所以拒绝原假设,不拒绝备择假设,表明模型存在异方差。此模型并未消除异方差。
综上所述,用加权二乘法w1的效果最好,所以模型为:
得方程模型为:
Y=0.821013X-17.69318
t=(48.67993)(2.815926)
R2=0.986676 F=2369.735 DW=0.605852
2)用对数模型法
用软件分析得:
Dependent Variable: LNY
Method: Least Squares
Date: 12/24/15 Time: 21:37
Sample: 1 34
Included observations: 34
Variable
Coefficient
Std. Error
t-Statistic
Prob.
LNX
0.946887
0.011228
84.33549
0.0000
C
0.201861
0.077905
2.591100
0.0143
R-squared
0.995521
Mean dependent var
6.687779
Adjusted R-squared
0.995381
S.D. dependent var
1.067124
S.E. of regression
0.072525
Akaike info criterion
-2.352753
Sum squared resid
0.168315
Schwarz criterion
-2.262967
Log likelihood
41.99680
Hannan-Quinn criter.
-2.322134
F-statistic
7112.475
Durbin-Watson stat
0.812150
Prob(F-statistic)
0.000000
得到模型为:
LnY=0.946887 LNX+0.201861
对此模型进行White检验得:
Heteroskedasticity Test: White
F-statistic
1.003964
Prob. F(2,31)
0.3780
Obs*R-squared
2.068278
Prob. Chi-Square(2)
0.3555
Scaled explained SS
1.469638
Prob. Chi-Square(2)
0.4796
Test Equation:
Dependent Variable: RESID^2
Method: Least Squares
Date: 12/24/15 Time: 21:45
Sample: 1 34
Included observations: 34
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
0.039547
0.046759
0.845753
0.4042
LNX
-0.011601
0.014012
-0.827969
0.4140
LNX^2
0.000932
0.001028
0.906774
0.3715
R-squared
0.060832
Mean dependent var
0.004950
Adjusted R-squared
0.000240
S.D. dependent var
0.006365
S.E. of regression
0.006364
Akaike info criterion
-7.192271
Sum squared resid
0.001255
Schwarz criterion
-7.057592
Log likelihood
125.2686
Hannan-Quinn criter.
-7.146342
F-statistic
1.003964
Durbin-Watson stat
2.022904
Prob(F-statistic)
0.378027
从上图中可以看出,nR2=2.068278,比较计算的统计量的临界值,因为nR2=2.068278<0.05(2)=5.9915,所以接受原假设,此模型消除了异方差。
综合两种方法,改进后的模型最好为:
LnY=0.946887 LNX+0.201861
(2)
1)考虑价格因素,首先用软件三者关系进行分析如下:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 21:51
Sample: 1 34
Included observations: 34
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.741684
0.019905
37.26095
0.0000
P
0.235025
0.271701
0.865012
0.3937
C
43.41715
71.22946
0.609539
0.5466
R-squared
0.979911
Mean dependent var
1295.802
Adjusted R-squared
0.978615
S.D. dependent var
1188.791
S.E. of regression
173.8449
Akaike info criterion
13.23830
Sum squared resid
936883.7
Schwarz criterion
13.37298
Log likelihood
-222.0511
Hannan-Quinn criter.
13.28423
F-statistic
756.0627
Durbin-Watson stat
1.681521
Prob(F-statistic)
0.000000
1)用Goldfeld-Quanadt检验如下:
①当样本为1-13时,进行回归分析:
Dependent Variable: P
Method: Least Squares
Date: 12/24/15 Time: 21:59
Sample: 1 13
Included observations: 13
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
-0.170484
0.203868
-0.836247
0.4225
Y
0.458660
0.209755
2.186646
0.0536
C
59.50496
7.385841
8.056627
0.0000
R-squared
0.956255
Mean dependent var
135.3231
Adjusted R-squared
0.947506
S.D. dependent var
36.95380
S.E. of regression
8.466678
Akaike info criterion
7.309328
Sum squared resid
716.8464
Schwarz criterion
7.439701
Log likelihood
-44.51063
Hannan-Quinn criter.
7.282530
F-statistic
109.2993
Durbin-Watson stat
0.637181
Prob(F-statistic)
0.000000
得∑e1i2=716.8464
②当样本为22-34时,做回归分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time:22:07
Sample: 22 34
Included observations: 13
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.641197
0.092678
6.918569
0.0000
P
-1.206222
1.114278
-1.082514
0.3044
C
795.6887
603.8605
1.317670
0.2170
R-squared
0.939696
Mean dependent var
2496.127
Adjusted R-squared
0.927635
S.D. dependent var
1022.591
S.E. of regression
275.0847
Akaike info criterion
14.27121
Sum squared resid
756715.7
Schwarz criterion
14.40158
Log likelihood
-89.76286
Hannan-Quinn criter.
14.24441
F-statistic
77.91291
Durbin-Watson stat
1.128778
Prob(F-statistic)
0.000001
得∑e2i2=756715.7
③根据Goldfeld-Quanadt检验,F统计量为:
F=∑e2i2 /∑e1i2 =756715.7/ 716.8464=1055.6176
在α=0.05水平下,分子分母的自由度均为11,查分布表得临界值F0.05(10,10)=2.98,因为F=1055.6176> F0.05(10,10)=2.98,所以拒绝原假设,此检验表明模型存在异方差。
2)用White检验,软件分析结果为:
Heteroskedasticity Test: White
F-statistic
7.312529
Prob. F(5,28)
0.0002
Obs*R-squared
19.25463
Prob. Chi-Square(5)
0.0017
Scaled explained SS
119.3072
Prob. Chi-Square(5)
0.0000
Test Equation:
Dependent Variable: RESID^2
Method: Least Squares
Date: 12/24/15 Time: 22:18
Sample: 1 34
Included observations: 34
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
79541.08
112647.3
0.706107
0.4860
X
209.4964
63.90400
3.278298
0.0028
X^2
-0.024133
0.010712
-2.252841
0.0323
X*P
-0.235137
0.106647
-2.204822
0.0358
P
-1175.326
1156.253
-1.016495
0.3181
P^2
1.637366
2.600020
0.629751
0.5340
R-squared
0.566313
Mean dependent var
27555.40
Adjusted R-squared
0.488869
S.D. dependent var
107990.9
S.E. of regression
77206.44
Akaike info criterion
25.50514
Sum squared resid
1.67E+11
Schwarz criterion
25.77450
Log likelihood
-427.5874
Hannan-Quinn criter.
25.59700
F-statistic
7.312529
Durbin-Watson stat
2.787044
Prob(F-statistic)
0.000171
从上图中可以看出,nR2=19.25463,比较计算的统计量的临界值,因为nR2=19.25463>0.05(5)=11.0705,所以拒绝原假设,不拒绝备择假设,表明模型存在异方差。
2)修正
①建立对数模型,用软件分析如下:
Dependent Variable: LNY
Method: Least Squares
Date: 12/24/15 Time: 22:24
Sample: 1 34
Included observations: 34
Variable
Coefficient
Std. Error
t-Statistic
Prob.
LNX
0.939605
0.013645
68.86088
0.0000
LNP
0.026821
0.028454
0.942609
0.3532
C
0.108230
0.126322
0.856784
0.3981
R-squared
0.995646
Mean dependent var
6.687779
Adjusted R-squared
0.995365
S.D. dependent var
1.067124
S.E. of regression
0.072652
Akaike info criterion
-2.322188
Sum squared resid
0.163625
Schwarz criterion
-2.187509
Log likelihood
42.47720
Hannan-Quinn criter.
-2.276259
F-statistic
3544.292
Durbin-Watson stat
0.930109
Prob(F-statistic)
0.000000
对此模型进行White检验:
Heteroskedasticity Test: White
F-statistic
3.523832
Prob. F(5,28)
0.0135
Obs*R-squared
13.13158
Prob. Chi-Square(5)
0.0222
Scaled explained SS
12.14373
Prob. Chi-Square(5)
0.0329
Test Equation:
Dependent Variable: RESID^2
Method: Least Squares
Date: 12/24/15 Time: 22:34
Sample: 1 34
Included observations: 34
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
0.422872
0.273746
1.544759
0.1336
LNX
0.080712
0.031833
2.535502
0.0171
LNX^2
-0.003917
0.003037
-1.289564
0.2078
LNX*LNP
-0.004955
0.005136
-0.964765
0.3429
LNP
-0.254992
0.129858
-1.963631
0.0596
LNP^2
0.026470
0.012675
2.088390
0.0460
R-squared
0.386223
Mean dependent var
0.004813
Adjusted R-squared
0.276620
S.D. dependent var
0.007286
S.E. of regression
0.006197
Akaike info criterion
-7.170690
Sum squared resid
0.001075
Schwarz criterion
-6.901332
Log likelihood
127.9017
Hannan-Quinn criter.
-7.078831
F-statistic
3.523832
Durbin-Watson stat
2.264261
Prob(F-statistic)
0.013502
从上图中可以看出,nR2=13.13158,比较计算的统计量的临界值,因为nR2=13.13158>0.05(5)=11.0705,所以拒绝原假设,不拒绝备择假设,表明模型存在异方差,所以此模型没有消除异方差。
②当w1=1/x时,用软件分析如下:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 22:49
Sample: 1 34
Included observations: 34
Weighting series: W1
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.723218
0.022965
31.49212
0.0000
P
0.719506
0.141085
5.099795
0.0000
C
-44.72084
13.11268
-3.410502
0.0018
Weighted Statistics
R-squared
0.992755
Mean dependent var
457.8505
Adjusted R-squared
0.992287
S.D. dependent var
41.70384
S.E. of regression
28.40494
Akaike info criterion
9.615100
Sum squared resid
25012.05
Schwarz criterion
9.749779
Log likelihood
-160.4567
Hannan-Quinn criter.
9.661030
F-statistic
2123.843
Durbin-Watson stat
1.298389
Prob(F-statistic)
0.000000
Unweighted Statistics
R-squared
0.977704
Mean dependent var
1295.802
Adjusted R-squared
0.976266
S.D. dependent var
1188.791
S.E. of regression
183.1446
Sum squared resid
1039800.
Durbin-Watson stat
1.740795
所得模型为:
Y=0.723218X+0.719506p-44.72084
对此模型进行White检验得:
Heteroskedasticity Test: White
F-statistic
2.088840
Prob. F(5,28)
0.0966
Obs*R-squared
9.236835
Prob. Chi-Square(5)
0.1000
Scaled explained SS
25.50696
Prob. Chi-Square(5)
0.0001
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 12/24/15 Time: 22:50
Sample: 1 34
Included observations: 34
Collinear test regressors dropped from specification
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
3861.793
1068.806
3.613183
0.0012
WGT^2
3260.199
4309.988
0.756429
0.4557
X*WGT^2
13.72241
8.453473
1.623287
0.1157
X*P*WGT^2
-0.151725
0.061588
-2.463567
0.0202
P^2*WGT^2
0.431162
0.278315
1.549186
0.1326
P*WGT^2
-76.13221
73.40636
-1.037134
0.3085
R-squared
0.271672
Mean dependent var
735.6486
Adjusted R-squared
0.141613
S.D. dependent var
1924.655
S.E. of regression
1783.177
Akaike info criterion
17.96897
Sum squared resid
89032169
Schwarz criterion
18.23832
Log likelihood
-299.4724
Hannan-Quinn criter.
18.06082
F-statistic
2.088840
Durbin-Watson stat
2.336495
Prob(F-statistic)
0.096616
因为nR2=9.236835<0.05(5)=11.0705,所以接受原假设。该模型不存在异方差,所以此模型消除了异方差。
③当w2=1/x2,用软件分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/24/15 Time: 23:00
Sample: 1 34
Included observations: 34
Weighting series: W2
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.639012
0.039216
16.29477
0.0000
P
1.200751
0.206023
5.828234
0.0000
C
-81.85973
15.77499
-5.189209
0.0000
Weighted Statistics
R-squared
0.991614
Mean dependent var
230.2433
Adjusted R-squared
0.991073
S.D. dependent var
247.1718
S.E. of regression
11.37136
Akaike info criterion
7.784170
Sum squared resid
4008.543
Schwarz criterion
7.918849
Log likelihood
-129.3309
Hannan-Quinn criter.
7.830100
F-statistic
1832.775
Durbin-Watson stat
1.167961
Prob(F-statistic)
0.000000
Unweighted Statistics
R-squared
0.956816
Mean dependent var
1295.802
Adjusted R-squared
0.954030
S.D. dependent var
1188.791
S.E. of regression
254.8849
Sum squared resid
2013955.
Durbin-Watson stat
1.002870
所得模型为:
Y=0.639012X+1.200751p-81.85973
对该模型进行White检验得:
Heteroskedasticity Test: White
F-statistic
43.19853
Prob. F(6,27)
0.0000
Obs*R-squared
30.79235
Prob. Chi-Square(6)
0.0000
Scaled explained SS
47.42430
Prob. Chi-Square(6)
0.0000
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 12/26/15 Time: 07:20
Sample: 1 34
Included observations: 34
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
27.51002
20.12556
1.366919
0.1829
WGT^2
-1245.193
837.2352
-1.487268
0.1485
X^2*WGT^2
0.007732
0.005450
1.418649
0.1674
X*WGT^2
7.948582
4.884597
1.627275
0.1153
X*P*WGT^2
-0.111755
0.064061
-1.744525
0.0924
P^2*WGT^2
0.184342
0.164562
1.120199
0.2725
P*WGT^2
-3.127017
23.56724
-0.132685
0.8954
R-squared
0.905657
Mean dependent var
117.8983
Adjusted R-squared
0.884692
S.D. dependent var
230.3570
S.E. of regression
78.22224
Akaike info criterion
11.73823
Sum squared resid
165205.4
Schwarz criterion
12.05248
Log likelihood
-192.5498
Hannan-Quinn criter.
11.84539
F-statistic
43.19853
Durbin-Watson stat
1.794799
Prob(F-statistic)
0.000000
因为nR2=30.79235>0.05(5)=11.0705,所以拒绝原假设,不拒绝备择假设,表明模型存在异方差,所以此模型没有消除异方差。
④当w3=1/sqr(x)时,用软件分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/26/15 Time: 07:34
Sample: 1 34
Included observations: 34
Weighting series: W3
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.744661
0.019825
37.56252
0.0000
P
0.451861
0.179971
2.510739
0.0175
C
-13.49643
25.37768
-0.531823
0.5986
Weighted Statistics
R-squared
0.989356
Mean dependent var
776.3266
Adjusted R-squared
0.988670
S.D. dependent var
367.3152
S.E. of regression
73.35237
Akaike info criterion
11.51252
Sum squared resid
166797.7
Schwarz criterion
11.64720
Log likelihood
-192.7129
Hannan-Quinn criter.
11.55845
F-statistic
1440.783
Durbin-Watson stat
1.599590
Prob(F-statistic)
0.000000
Unweighted Statistics
R-squared
0.979407
Mean dependent var
1295.802
Adjusted R-squared
0.978079
S.D. dependent var
1188.791
S.E. of regression
176.0098
Sum squared resid
960362.6
Durbin-Watson stat
1.761225
所得模型为:
Y=0.744661X+0.451861p-13.49643
对所得模型进行White检验得:
Heteroskedasticity Test: White
F-statistic
4.459272
Prob. F(5,28)
0.0041
Obs*R-squared
15.07219
Prob. Chi-Square(5)
0.0101
Scaled explained SS
72.39077
Prob. Chi-Square(5)
0.0000
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 12/26/15 Time: 07:43
Sample: 1 34
Included observations: 34
Collinear test regressors dropped from specification
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
61163.22
27531.93
2.221538
0.0346
WGT^2
28251.98
17350.39
1.628320
0.1147
X^2*WGT^2
-0.001093
0.006624
-0.164950
0.8702
X*P*WGT^2
-0.235836
0.077110
-3.058447
0.0049
P^2*WGT^2
1.236884
0.644872
1.918030
0.0654
P*WGT^2
-503.3080
262.5884
-1.916718
0.0655
R-squared
0.443300
Mean dependent var
4905.814
Adjusted R-squared
0.343889
S.D. dependent var
16926.97
S.E. of regression
13710.96
Akaike info criterion
22.04856
Sum squared resid
5.26E+09
Schwarz criterion
22.31792
Log likelihood
-368.8256
Hannan-Quinn criter.
22.14042
F-statistic
4.459272
Durbin-Watson stat
2.450171
Prob(F-statistic)
0.004103
因为nR2=15.07219>0.05(5)=11.0705,所以拒绝原假设,不拒绝备择假设,表明模型存在异方差,所以此模型没有消除异方差。
综上所述,修改后的模型为:
Y= Y=0.723218X+0.719506p-44.72084
t=(31.49212) (5.099705) (-3.410502)
R2=0.992755 F=2123.843 DW=1.298389
(3)体会:对于不同的模型,可采取对数模型法或者加权二乘法对具有异方差性的模型进行改进,从而消除异方差。但对于不同的模型,自由度的不同,可能导致改进的方法不同,所以要对改进的模型进行进一步的检验才行。
6.1
(1)建立居民收入-消费模型,用Eviews分析结果如下:
Dependent Variable: Y
Method: Least Squares
Date: 12/26/15 Time: 08:22
Sample: 1 19
Included observations: 19
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
0.690488
0.012877
53.62068
0.0000
C
79.93004
12.39919
6.446390
0.0000
R-squared
0.994122
Mean dependent var
700.2747
Adjusted R-squared
0.993776
S.D. dependent var
246.4491
S.E. of regression
19.44245
Akaike info criterion
8.872095
Sum squared resid
6426.149
Schwarz criterion
8.971510
Log likelihood
-82.28490
Hannan-Quinn criter.
8.888920
F-statistic
2875.178
Durbin-Watson stat
0.574663
Prob(F-statistic)
0.000000
所得模型为:
Y=0.690488X+79.93004
Se=(0.012877)(12.39919)
t=(53.62068)(6.446390)
R2=0.994122 F=2875.178 DW=0.574663
(2)
1)检验模型中存在的问
题
快递公司问题件快递公司问题件货款处理关于圆的周长面积重点题型关于解方程组的题及答案关于南海问题
①做出残差图如下:
残差的变动有系统模式,连续为正和连续为负,表明残差项存在一阶自相关。
②该回归方程可决系数较高,回归系数均显著。对样本量为19,一个解释变量的模型,5%的显著水平,查DW统计表可知,dL=1.180,dU=1.401,模型中DW=0.574663,< dL,显然模型中有自相关。
③对模型进行BG检验,用Eviews分析结果如下:
Breusch-Godfrey Serial Correlation LM Test:
F-statistic
4.811108
Prob. F(2,15)
0.0243
Obs*R-squared
7.425088
Prob. Chi-Square(2)
0.0244
Test Equation:
Dependent Variable: RESID
Method: Least Squares
Date: 12/26/15 Time: 08:27
Sample: 1 19
Included observations: 19
Presample missing value lagged residuals set to zero.
Variable
Coefficient
Std. Error
t-Statistic
Prob.
X
-0.003275
0.010787
-0.303586
0.7656
C
1.929546
10.35593
0.186323
0.8547
RESID(-1)
0.608886
0.292707
2.080189
0.0551
RESID(-2)
0.089988
0.291120
0.309110
0.7615
R-squared
0.390794
Mean dependent var
-1.65E-13
Adjusted R-squared
0.268953
S.D. dependent var
18.89466
S.E. of regression
16.15518
Akaike info criterion
8.587023
Sum squared resid
3914.848
Schwarz criterion
8.785852
Log likelihood
-77.57671
Hannan-Quinn criter.
8.620672
F-statistic
3.207406
Durbin-Watson stat
1.570723
Prob(F-statistic)
0.053468
如上表显示,LM=TR2=7.425088,其p值为0.0244,表明存在自相关。
2)对模型进行处理:
①采取广义差分法
a)为估计自相关系数ρ。对et进行滞后一期的自回归,用EViews分析结果如下:
Dependent Variable: E
Method: Least Squares
Date: 12/26/15 Time: 08:34
Sample (adjusted): 2 19
Included observations: 18 after adjustments
Variable
Coefficient
Std. Error
t-Statistic
Prob.
E(-1)
0.657352
0.177626
3.700759
0.0018
R-squared
0.440747
Mean dependent var
1.717433
Adjusted R-squared
0.440747
S.D. dependent var
17.85134
S.E. of regression
13.34980
Akaike info criterion
8.074833
Sum squared resid
3029.692
Schwarz criterion
8.124298
Log likelihood
-71.67349
Hannan-Quinn criter.
8.081653
Durbin-Watson stat
1.634573
由上可知,ρ=0.657352
b)对原模型进行广义差分回归,用Eviews进行分析所得结果如下:
Dependent Variable: Y-0.657352*Y(-1)
Method: Least Squares
Date: 12/26/15 Time: 08:41
Sample (adjusted): 2 19
Included observations: 18 after adjustments
Variable
Coefficient
Std. Error
t-Statistic
Prob.
C
35.97761
8.103546
4.439737
0.0004
X-0.657352*X(-1)
0.668695
0.020642
32.39512
0.0000
R-squared
0.984983
Mean dependent var
278.1002
Adjusted R-squared
0.984044
S.D. dependent var
105.1781
S.E. of regression
13.28570
Akaike info criterion
8.115693
Sum squared resid
2824.158
Schwarz criterion
8.214623
Log likelihood
-71.04124
Hannan-Quinn criter.
8.129334
F-statistic
1049.444
Durbin-Watson stat
1.830746
Prob(F-statistic)
0.000000
由上图可知回归方程为:
Yt*=35.97761+0.668695Xt*
Se=(8.103546)(0.020642)
t=(4.439737)(32.39512)
R2=0.984983 F=1049.444 DW=1.830746
式中,Yt*=Yt-0.657352Yt-1, Xt*=Xt-0.657352Xt-1
由于使用了广义差分数据,样本容量减少了1个,为18个。查5%显著水平的DW统计表可知,dL=1.158,dU=1.391模型中DW=1,830746,du
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