计量经济学庞皓第三版课后答案解析
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计量经济学庞皓第三版课后
答案解析
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第二章简单线性回归模型
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(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: 12/27/14 Time: 21:00
Sample: 1 22
Included observations: 22
Variable Coefficien
t Std. Error t-Statistic Prob.
C X1
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
有上可知,关系式为y=+
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: 11/26/14 Time: 21:10
Sample: 1 22
Included observations: 22
Variable Coefficien
t Std. Error t-Statistic Prob.
C X2
R-squared
Mean dependent var
Adjusted R-squared. dependent var
. of regression
Akaike info criterion
Sum squared resid Schwarz
criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
由上可知,关系式为y=+
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: 11/26/14 Time: 21:14
Sample: 1 22
Included observations: 22
Variable Coefficien
t Std. Error t-Statistic Prob.
C X3
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
由上可知,关系式为y=+
(2)①关于人均寿命与人均GDP模型,由上可知,可决系数为,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(β
1
)=>(20)=,对斜率系数的显著性检验表明,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,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(β
2
)=>(20)=,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,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(β
3
)=>(20)=,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。
(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: 12/03/14 Time: 17:00
Sample (adjusted): 1 33
Included observations: 33 after adjustments
Variable Coefficien
t Std. Error t-Statistic Prob.
X C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
②由上可知,模型的参数:斜率系数,截距为—
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,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)=>(31)=,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=—
t= ()
R2= F= 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亿元。
(2)当x=32000时,
①进行点预测,由上可知Y=—,代入可得:
Y= Y=*32000—=
②进行区间预测:
∑x2=∑(X
i —X)2=δ2
x
(n—1)= x (33—1)=
(X
f
—X)2=(32000—2=
当Xf=32000时,将相关数据代入计算得到:
—即Yf的置信区间为(—, +)
(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: 12/03/14 Time: 18:00
Sample (adjusted): 1 33
Included observations: 33 after adjustments
Variable Coefficien
t Std. Error t-Statistic Prob.
LNX C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
①模型方程为:lnY=由上可知,模型的参数:斜率系数为,截距为
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,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(β
2
)=>(31)=,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%
(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: 12/01/14 Time: 12:40
Sample: 1 12
Included observations: 12
Variable Coefficien
t Std. Error t-Statistic Prob.
X C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
由上可得:建筑面积与建造成本的回归方程为:
Y=(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元。
(3)
①首先进行点预测,由Y=得,当x=,y=
②再进行区间估计:
∑x2=∑(X
i —X)2=δ2
x
(n—1)= x (12—1)=
(X
f
—X)2=—2=0.
当Xf=时,将相关数据代入计算得到:—即Yf的置信区间为(—, +)
(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: 11/25/14 Time: 12:38
Sample: 1 31
Included observations: 31
Variable Coefficien
t Std. Error t-Statistic Prob.
X2 X3 X4 C
R-squared
Mean dependent var
Adjusted R-squared. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)②得到模型得:
Y=+ X
4
③对模型进行检验:
1)可决系数是,修正的可决系数为,说明模型对样本拟合较好
2)F检验,F=>F(3,27)=,回归方程显著。
3)t检验,t统计量分别为,,,,均大于
t(27)=,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辆,城镇人口比重增加1个百分点,百户拥有家用汽车减少辆,交通工具消费价格指数每上升1,百户拥有家用汽车减少辆。
(3)用EViews分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/08/14 Time: 17:28
Sample: 1 31
Included observations: 31
Variable Coefficien
t Std. Error t-Statistic Prob.
X2 LNX3 LNX4 C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
模型方程为:
Y= LNX
4
+
此分析得出的可决系数为>,拟合程度得到了提高,可这样改进。
(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: 12/01/14 Time: 20:25
Sample: 1994 2011
Included observations: 18
Variable Coefficien
t Std. Error t-Statistic Prob.
X2 X3 C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid8007316.
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
①由上可知,模型为:
Y = + -
②对模型进行检验:
1)可决系数是,修正的可决系数为,说明模型对样本拟合较好
2)F检验,F=>F(2,15)=,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,大于t(15)=,系数是显著的,X3的系数对应t值为,小于t(15)=,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: 12/01/14 Time: 20:25
Sample: 1994 2011
Included observations: 18
Variable Coefficien
t Std. Error t-Statistic Prob.
LNX2 LNX3 C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
①由上可知,模型为:
LNY=+ LNX
2+ LNX
3
②对模型进行检验:
1)可决系数是,修正的可决系数为,说明模型对样本拟合较好。
2)F检验,F=> F(2,15)=,回归方程显著。
3)t检验,t统计量分别为,,,均大于t(15)=,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,出口货物总额增加亿元,人民币汇率增加1,出口货物总额增加亿元。
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%,人民币汇率每增加1%,出口货物总额增加%
(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: 12/01/14 Time: 20:30
Sample: 1 18
Included observations: 18
Variable Coefficien
t Std. Error t-Statistic Prob.
X T C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
①模型为:Y = + 对模型进行检验:
1)可决系数是,修正的可决系数为,说明模型对样本拟合较好。
2)F检验,F=> F(2,15)=,回归方程显著。
3)t检验,t统计量分别为,,均大于t(15)=,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元,户主受教育年数增加1年,家庭书刊年消费支出增加元。
(2)用Eviews分析:
①
Dependent Variable: Y
Method: Least Squares
Date: 12/01/14 Time: 22:30
Sample: 1 18
Included observations: 18
Variable Coefficien
t Std. Error t-Statistic Prob.
T C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
②
Dependent Variable: X Method: Least Squares
Date: 12/01/14 Time: 22:34 Sample: 1 18
Included observations: 18
Variable Coefficien
t Std. Error t-Statistic Prob.
T C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid4290746.
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
以上分别是y与T,X与T的一元回归
模型分别是:
Y = -
X = +
(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: 12/03/14 Time: 20:39
Sample: 1 18
Included observations: 18
Variable Coefficien
t Std. Error t-Statistic Prob.
E2 C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
模型为:
E
1
= +
参数:斜率系数α为,截距为
(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。
(1)预期的符号是X
1,X
2
,X
3
,X
4
,X
5
的符号为正,X
6
的符号为负
(2)根据Eviews分析得到数据如下:Dependent Variable: Y
Method: Least Squares
Date: 12/04/14 Time: 13:24
Sample: 1994 2011
Included observations: 18
Variable Coefficien
t Std. Error t-Statistic Prob.
X2 X3 X4 X5 X6 C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
①与预期不相符。
②评价:
1)可决系数为,数据相当大,可以认为拟合程度很好。
2)F检验,F=>F()=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:,,,,,均小于t(12)=,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: 12/03/14 Time: 11:12
Sample: 1994 2011
Included observations: 18
t
X5
X6
C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
①得到模型的方程为:
Y= X
6
+
②评价:
1)可决系数为,数据相当大,可以认为拟合程度很好。
2)F检验,F=>F()=3,89,回归方程显著
3)T检验,X5 系数对应的t值为,大于t(12)=,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,小于t(12)=,所以系数是不显著的。
(1)根据Eviews分析得到数据如下:Dependent Variable: LNY
Method: Least Squares
Date: 12/05/14 Time: 11:39
Sample: 1985 2011
Included observations: 27
Variable Coefficien
t Std. Error t-Statistic Prob.
LNGDP LNCPI
C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
得到的模型方程为:
LNY=
(2)
①该模型的可决系数为,可决系数很高,F检验值为,
明显显著。
但当α=时,t(24)=,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:
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: 12/03/14 Time: 14:41
Sample: 1985 2011
Included observations: 27
Variable Coefficien
t Std. Error t-Statistic Prob.
LNGDP
C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
b)
Dependent Variable: LNY Method: Least Squares
Date: 12/03/14 Time: 14:41 Sample: 1985 2011
Included observations: 27
Variable Coefficien
t Std. Error t-Statistic Prob.
LNCPI
C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
c)
Dependent Variable: LNGDP Method: Least Squares
Date: 12/05/14 Time: 11:11 Sample: 1985 2011
Included observations: 27
Variable Coefficien
t Std. Error t-Statistic Prob.
LNCPI
C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
①得到的回归方程分别为
1)LNY=
2)LNY=
3)LNGDP t=
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。
(1)按照设计的理论模型,由Eviews分析得:
Dependent Variable: CZSR
Method: Least Squares
Date: 12/03/14 Time: 11:40
Sample: 1985 2011
Included observations: 27
Variable Coefficien
t Std. Error t-Statistic Prob.
CZZC GDP SSZE C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid2866884.
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
从回归结果可见,可决系数为,校正的可决系数为,模型拟合的很好。
F的统计量为,说明在α=,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:
高,说明确实存在多重共线性。
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。
(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,
②Goldfeld-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: 12/10/14 Time: 14:52
Sample: 1 7
Included observations: 7
Variable Coefficien
t Std. Error t-Statistic Prob.
T X C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
得∑e
1i
2=
2)定义区间为12-18时,由软件分析得:
Dependent Variable: Y Method: Least Squares
Date: 12/10/14 Time: 13:50 Sample: 12 18
Included observations: 7
Variable Coefficien
t Std. Error t-Statistic Prob.
T X C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
得∑e
2i
2=
3)根据Goldfeld-Quanadt检验,F统计量为:
F=∑e
2i 2 /∑e
1i
2 ==
在α=水平下,分子分母的自由度均为4,查分布表得临界值(4,4)=,因为F=< (4,4)=,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:
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。
(1)由Eviews软件分析得:Dependent Variable: Y Method: Least Squares
Date: 12/10/14 Time: 16:00 Sample: 1 31
Included observations: 31
Variable Coefficien
t Std. Error t-Statistic Prob.
X C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
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=+
(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: 12/10/14 Time: 11:34
Sample: 1 12
Included observations: 12
Variable Coefficien
t Std. Error t-Statistic Prob.
X1 C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid1772245.
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
得∑e
1i
2=1772245.
2)定义区间为20-31时,由软件分析得:
Dependent Variable: Y1 Method: Least Squares
Date: 12/10/14 Time: 16:36 Sample: 20 31
Included observations: 12
Variable Coefficien
t Std. Error t-Statistic Prob.
X1 C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid7909670.
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
得∑e
2i
2=7909670.
3)根据Goldfeld-Quanadt检验,F统计量为:
F=∑e
2i 2 /∑e
1i
2 =7909670./ 1772245=
在α=水平下,分子分母的自由度均为10,查分布表得临界值(10,10)=,因为F=> (10,10)=,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: 12/09/14 Time: 11:13
Sample: 1 31
Included observations: 31
Weighting series: W1
Variable Coefficien
t Std. Error t-Statistic Prob.
X
C
Weighted Statistics
R-squared Mean dependent
var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid8352726.
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
Unweighted Statistics
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Sum squared resid
Durbin-Watson stat
对此模型进行White检验得:
Heteroskedasticity Test: White
F-statistic Prob. F(2,28)
Obs*R-squared
Prob. Chi-Square(2)
Scaled explained SS
Prob. Chi-Square(2)
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 12/10/14 Time: 21:13
Sample: 1 31
Included observations: 31
Collinear test regressors dropped from specification
Variable Coefficien
t Std. Error t-Statistic Prob.
C1045682. WGT^21173622. X*WGT^2
R-squared
Mean dependent var
Adjusted R-squared. dependent
var
. of regression
Akaike info criterion
Sum squared resid+13
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
从上可知,nR2=,比较计算的统计量的临界值,因为nR2=<(2)=,所以接受原假设,该模型消除了异方差。
估计结果为:
Y= t=()()
R2= F= DW=
②用权数w2=1/x2,用回归分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/09/14 Time: 21:08
Sample: 1 31
Included observations: 31
Weighting series: W2
Variable Coefficien
t Std. Error t-Statistic Prob.
X
C
Weighted Statistics
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid6320554.
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
Unweighted Statistics
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Sum squared resid
Durbin-Watson stat
对此模型进行White检验得:
Heteroskedasticity Test: White
F-statistic Prob. F(3,27)
Obs*R-squared
Prob. Chi-Square(3)
Scaled explained SS
Prob. Chi-Square(3)
Test Equation:
Dependent Variable: WGT_RESID^2 Method: Least Squares
Date: 12/10/14 Time: 21:29 Sample: 1 31
Included observations: 31
Variable Coefficien
t Std. Error t-Statistic Prob.
C
WGT^22240181. X^2*WGT^2
X*WGT^2
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid+12
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
从上可知,nR2=,比较计算的统计量的临界值,因为nR2=<(2)=,所以接
受原假设,该模型消除了异方差。
估计结果为:
Y= t=()()
R2= F= DW=
③用权数w3=1/sqr(x),用回归分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/09/14 Time: 21:35
Sample: 1 31
Included observations: 31
Weighting series: W3
Variable Coefficien
t Std. Error t-Statistic Prob.
X
C
Weighted Statistics
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid9990985.
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
Unweighted Statistics
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Sum squared resid
Durbin-Watson stat
对此模型进行White检验得:Heteroskedasticity Test: White
F-statistic Prob. F(2,28)
Obs*R-squared
Prob. Chi-Square(2)
Scaled explained SS
Prob. Chi-Square(2)
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 12/09/14 Time: 20:36
Sample: 1 31
Included observations: 31
Collinear test regressors dropped from specification
Variable Coefficien
t Std. Error t-Statistic Prob.
C1212308.2141958. WGT^21301839. X^2*WGT^2
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid+13
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
从上可知,nR2=,比较计算的统计量的临界值,因为nR2=<(2)=,所以接
受原假设,该模型消除了异方差。
估计结果为:
Y= t=()()
R2= F= DW=
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= t=()()
R2= F= DW=
(1)
a)用Eviews模型分析得:Dependent Variable: Y Method: Least Squares
Date: 12/10/14 Time: 20:16 Sample: 1978 2011
Included observations: 34
Variable Coefficien
t Std. Error t-Statistic Prob.
X C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
得回归模型为:
Y= X+
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: 12/11/14 Time: 11:47
Sample: 1 13
Included observations: 13
Variable Coefficien
t Std. Error t-Statistic Prob.
X C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
得∑e
1i
2=
2)当定义区间为1-13时,由软件分析得:
Dependent Variable: Y
Method: Least Squares
Date: 12/11/14 Time: 12:21
Sample: 22 34
Included observations: 13
Variable Coefficien
t Std. Error t-Statistic Prob.
X C
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid Schwarz
criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
得∑e
2i
2=
3)根据Goldfeld-Quanadt检验,F统计量为:
F=∑e
2i 2 /∑e
1i
2 = =
在α=水平下,分子分母的自由度均为11,查分布表得临界值(11,11)=,因为F=> (11,11)=,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 Prob. F(2,31)
Obs*R-squared
Prob. Chi-Square(2)
Scaled explained SS
Prob. Chi-Square(2)
Test Equation:
Dependent Variable: RESID^2 Method: Least Squares
Date: 12/11/14 Time: 12:56 Sample: 1 34
Included observations: 34
Variable Coefficien
t Std. Error t-Statistic Prob.
C X X^2
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid+11
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic Durbin-Watson
Prob(F-statistic)
从上图中可以看出,nR2=,比较计算的统计量的临界值,因为nR2=>(2)=,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: 12/11/14 Time: 13:22
Sample: 1 34
Included observations: 34
Weighting series: W1
Variable Coefficien
t Std. Error t-Statistic Prob.
X
C
Weighted Statistics
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
Unweighted Statistics
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression Sum squared 1489089.
Durbin-Watson stat
得方程模型为:
Y= t=()()
R2= F= DW=
对此模型进行White检验如下:
Heteroskedasticity Test: White
F-statistic Prob. F(2,31)
Obs*R-squared
Prob. Chi-Square(2)
Scaled explained SS
Prob. Chi-Square(2)
Test Equation:
Dependent Variable: WGT_RESID^2
Method: Least Squares
Date: 12/11/14 Time: 11:20
Sample: 1 34
Included observations: 34
Collinear test regressors dropped from specification
Variable Coefficien
t Std. Error t-Statistic Prob.
C WGT^2 X*WGT^2
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
从上图中可以看出,nR2=,比较计算的统计量的临界值,
因为nR2=<(2)=,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: 12/11/14 Time: 13:27 Sample: 1 34
Included observations: 34
Weighting series: W2
Variable Coefficien
t Std. Error t-Statistic Prob.
X
C
Weighted Statistics
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
Unweighted Statistics
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Sum squared
resid2138654.
Durbin-Watson stat
得方程模型为:
Y=+
t=()()
R2= F= DW=
用White检验模型得:
Heteroskedasticity Test: White
F-statistic Prob. F(3,30)
Obs*R-squared
Prob. Chi-Square(3)
Scaled explained SS
Prob. Chi-Square(3)
Test Equation:
Dependent Variable: WGT_RESID^2 Method: Least Squares
Date: 12/11/14 Time: 11:19 Sample: 1 34
Included observations: 34
Variable Coefficien
t Std. Error t-Statistic Prob.
C WGT^2
X^2*WGT^2 X*WGT^2
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid3583851.
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
从上图中可以看出,nR2=,比较计算的统计量的临界值,因为nR2=>(2)
=,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: 12/11/14 Time: 13:21
Sample: 1 34
Included observations: 34
Weighting series: W3
Variable Coefficien Std. Error t-Statistic Prob.
t
X
C
Weighted Statistics
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
Unweighted Statistics
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Sum squared
resid1045123.
Durbin-Watson stat
得方程模型为:
Y=+
t=()()
R2= F= DW=
对所得模型进行White检验:
Heteroskedasticity Test: White
F-statistic Prob. F(2,31)
Obs*R-squared
Prob. Chi-Square(2)
Scaled explained SS
Prob. Chi-Square(2)
Test Equation:
Dependent Variable: WGT_RESID^2 Method: Least Squares
Date: 12/10/14 Time: 13:23 Sample: 1 34
Included observations: 34
Collinear test regressors dropped from specification
Variable Coefficien
t Std. Error t-Statistic Prob.
C WGT^2
X^2*WGT^2
R-squared
Mean dependent var
Adjusted R-squared
. dependent var
. of regression
Akaike info criterion
Sum squared resid+09
Schwarz criterion
Log likelihood
Hannan-Quinn criter.
F-statistic
Durbin-Watson stat
Prob(F-statistic)
从上图中可以看出,nR2=,比较计算的统计量的临界值,因为nR2=>(2)
=,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= t=()()
R2= F= DW=
2)用对数模型法
用软件分析得:
Dependent Variable: LNY
Method: Least Squares
Date: 12/11/14 Time: 09:54
Sample: 1 34
Included observations: 34
Variable Coefficien
t Std. Error t-Statistic Prob.
LNX
C
R-squared Mean dependent。