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计量经济学庞皓第三版课后答案

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计量经济学庞皓第三版课后答案 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: 12/27/14 Time: 21:00 Sample: 1 22 Included observations: 22 Variable Coefficient Std. Error t-Statistic Prob. C 56.64794 1.960820 28.88992 0....

计量经济学庞皓第三版课后答案
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: 12/27/14 Time: 21:00 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+0.128360x 1 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 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+0.331971x 2 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 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+0.387276x 3 (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(β 1)=4.711834>t 0.025 (20)=2.086 ,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 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(β 2)=7.115308>t 0.025 (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(β 3)=4.825285>t 0.025 (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: 12/03/14 Time: 17:00 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>t 0.025 (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 编程规范下载gsp规范下载钢格栅规范下载警徽规范下载建设厅规范下载 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, ∑x 2 =∑(Xi—X) 2 =δ 2 x(n—1)= 7608.021 2 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: 12/03/14 Time: 18:00 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(β 2) =28.58268>t 0.025 (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: 12/01/14 Time: 12:40 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, ∑x 2 =∑(Xi—X) 2 =δ 2 x(n—1)= 1.989419 2 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 —2.228x31.73600 x√1/12+43.5357/0.95387843 ≤ Yf ≤1556.647 +2.228x31.73600 x√ 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: 11/25/14 Time: 12:38 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+5.996865X 2- 0.524027 X 3-2.265680 X 4 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: 12/08/14 Time: 17:28 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 X 2-22.81005 LNX 3-230.8481 LNX 4+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: 12/01/14 Time: 20:25 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 = 0.135474X 2 + 18.85348X 3 - 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: 12/01/14 Time: 20:25 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 LNX 2+1.760695 LNX 3 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: 12/01/14 Time: 20:30 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: 12/01/14 Time: 22:30 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: 12/01/14 Time: 22:34 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: 12/03/14 Time: 20:39 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 = 0.086450E 2 + 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: 12/04/14 Time: 13:24 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: 12/03/14 Time: 11:12 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 X 5-0.054965 X 6+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: 12/05/14 Time: 11:39 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 LNGDP t-0.421791 LNCPI t-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: 12/03/14 Time: 14:41 Sample: 1985 2011 Included observations: 27 Variable Coefficient Std. Error t-Statistic Prob. LNGDP 1.185739 0.027822 42.61933 0.0000 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: 12/03/14 Time: 14:41 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: 12/05/14 Time: 11:11 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 LNGDP t-3.750670 2)LNY=2.939295 LNCPI t-6.854535 3)LNGDP t=2.511022 LNCPI t-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 领导形象设计圆作业设计ao工艺污水处理厂设计附属工程施工组织设计清扫机器人结构设计 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 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: 0 5,000 10,000 15,000 20,000 25,000 30,000 1,000 1,500 2,000 2,500 3,000 3,500 4,000 X E 2 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: 12/10/14 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∑ e1i 2 =4002.499 2)定义区间为 12-18 时,由软件分析得: Dependent Variable: Y Method: Least Squares Date: 12/10/14 Time: 13:50 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∑ e2i 2 =6918.280 3)根据 Goldfeld-Quanadt 检验, F 统计量为: F=∑e2i 2 / ∑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 F 0.05( 4,4)=6.39 ,因为 F=1.7285< F 0.05( 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: 12/10/14 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 0 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000 6,000,000 0 2,000 4,000 6,000 8,000 10,000 X E2 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 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∑ e1i 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 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∑ e2i 2 =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 F 0.05( 10,10 )=2.98 , 因为 F=4.4631> F 0.05 (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: 12/09/14 Time: 11:13 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: 12/10/14 Time: 21:13 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, nR 2=0.649065 ,比较计算的 统计量的临界值,因为 nR 2=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/x 2,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 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: 12/10/14 Time: 21:29 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, nR 2=0.999322 ,比较计算的 统计量的临界值,因为 nR 2=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: 12/09/14 Time: 21:35 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: 12/09/14 Time: 20:36 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, nR 2=0.911022 ,比较计算的 统计量的临界值,因为 nR 2=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: 12/10/14 Time: 20:16 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: 12/11/14 Time: 11:47 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∑ e1i 2 =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: 12/11/14 Time: 12:21 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∑ e2i 2 =845390.4 3)根据 Goldfeld-Quanadt 检验, F 统计量为: F=∑e2i 2 / ∑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 F 0.05( 11,11 )=4.47 , 因为 F=518.8669> F 0.05(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: 12/11/14 Time: 12:56 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 , nR 2=13.62701 , 比 较 计 算 的 统 计 量 的 临 界 值 , 因 为 nR 2=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: 12/11/14 Time: 13:22 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: 12/11/14 Time: 11:20 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, nR 2=2.720457 ,比较计算的 统计量的临界值, 因为 nR 2=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/x 2 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 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: 12/11/14 Time: 11:19 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 , nR 2=14.52935 , 比 较 计 算 的 统 计 量 的 临 界 值 , 因 为 nR 2=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: 12/11/14 Time: 13:21 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: 12/10/14 Time: 13:23 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 , nR 2=11.72514 , 比 较 计 算 的 统 计 量 的 临 界 值 , 因 为 nR 2=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: 12/11/14 Time: 09:54 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: 12/11/14 Time: 09:55 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 , nR 2=2.068278 , 比 较 计 算 的 统 计 量 的 临 界 值 , 因 为 nR 2=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: 12/12/14 Time: 19:26 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: 12/14/14 Time: 19:26 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∑ e1i 2 =716.8464 ②当样本为 22-34 时,做回归分析得: Dependent Variable: Y Method: Least Squares Date: 12/14/14 Time:20:39 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∑ e2i 2 =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 F 0.05( 10,10 )=2.98 , 因为 F=1055.6176> F 0.05 (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: 12/12/14 Time: 19:31 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 , nR 2=19.25463 , 比 较 计 算 的 统 计 量 的 临 界 值 , 因 为 nR 2=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: 12/12/14 Time: 19:24 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: 12/12/14 Time: 19:24 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 , nR 2=13.13158 , 比 较 计 算 的 统 计 量 的 临 界 值 , 因 为 nR 2=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: 12/13/14 Time: 18:49 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: 12/14/14 Time: 19:57 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 nR 2=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/x 2,用软件分析得: Dependent Variable: Y Method: Least Squares Date: 12/15/14 Time: 20:02 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: 12/14/14 Time: 19:20 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 nR 2=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: 12/14/14 Time: 19:06 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: 12/14/14 Time: 19:08 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 nR 2=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: 12/20/14 Time: 14:22 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 ①做出残差图如下: -40 -30 -20 -10 0 10 20 30 40 50 2 4 6 8 10 12 14 16 18 Y Residuals 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: 12/20/14 Time: 15:03 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 e t 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: 12/20/14 Time: 15:04 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: 12/20/14 Time: 15:04 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: Y t*=35.97761+0.668695X t* Se=(8.103546)(0.020642) t=(4.439737)(32.39512) R2=0.984983 F=1049.444 DW=1.830746 式中, Yt*=Y t-0.657352Y t-1 , X t*=X t-0.657352X t-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,d U =1.391 模型中 DW=1,830746 ,du
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