我国农村居民消费水平影响因素实证分析2021 年 01 月 17 日【摘要】农业、农村、农民问题一直是近几年来国家关注的重点在经济不景气的状况下,如何开发农村市场、拉动内需也是讨论热点本文采用计量经济学统计方法,搜集1990-2021年间的有关数据,通过建立多元线性回归模型的方式,对影响农村居民消费水平的因素进行分析在初步建立模型、参数估计的根底上,先后对模型进行了经济意义检验、统计检验和计量经济学检验,并进行了相应的修正;最后得出结论:我国农村居民消费水平主要受到纯收入的影响,并与人均国内生产总值有较强的相关关系关键词】农村居民消费水平、多元回归、计量经济学检验1. 前言在经济危机和欧债危机的影响下,国际经济环境下行趋势明显在此背景下,我国出口形势严峻;而投资过热一直为人所诟病,拉动国内消费成为近些年来经济政策的重点我国是一个农业大国,拉动内需很大程度上要依赖开发农村市场、提高农村居民的购置力农村居民的购置力表达在其消费水平方面鉴于此,对影响农村居民消费水平的因素进行分析具有重要意义居民消费水平是指居民在物质产品和劳务的消费过程中,对满足人们生存、开展和享受需要方面所到达的程度。
通过消费的物质产品和劳务的数量和质量反映出来本文中的农村居民消费水平同国家统计年鉴的计量保持一致,即按常住人口平均计算的居民消费支出2. 变量被解释变量即为农村居民消费水平,按国内生产总值口径,即包括劳务消费在内的总农村居民消费水平消费进行计算的计算公式为:农村居民消费水平〔元/人〕= 报告期国内生产总值中的农村居民消费总额/报告期农村年平均人口解释变量的选择应当遵循一定的经济理论居民的消费水平在很大程度上受整体经济状况的影响农村居民消费水平亦是国内生产总值(GDP〕是用于衡量一国总收入的一种整体经济指标,经济扩张时期,居民收入稳定,GDP也高,居民用于消费的支出较多,消费水平较高;反之,经济收缩时,收入下降,GDP也低,用于消费的支出较少,消费水平随之下降为了与农村居民消费水平的统计口径一致,本文选取了人均国内生产总值作为解释变量之一初步分析,农村居民消费水平同人均国内生产总值之间存在正相关关系S.Kuznets的长期消费函数C=kY认为,消费水平是收入的函数,因此引入农村居民年人均纯收入作为解释变量之一,且认为农村居民的消费水平随着年人均纯收入的增长而增长基于边际消费倾向的性质,农村居民年人均纯收入的系数取值范围为〔0,1〕。
另外,农村居民的消费水平受到价格水平的影响根据根本供求理论,对于正常商品而言,价格上升那么需求下降,反之需求上升所以,模型建立中应当参加价格的影响因素本文选取了商品零售价格指数来反映价格对消费水平的影响商品零售价格指数是反映一定时期内城乡商品零售价格变动趋势和程度的相对数商品零售价格的变动与国家的财政收入、市场供需的平衡、消费与积累的比例关系有关因此,该指数可以从一个侧面对上述经济活动进行观察和分析初步分析,商品零售价格指数的系数应为负恩格尔系数〔%〕=食品支出总额/家庭或者个人消费支出总额*100%,该系数被用来衡量家庭和国家的富足程度,系数越大说明生活越穷困,反之那么越富裕恩格尔系数也可以反映居民消费水平,故推断二者之间存在相关关系,且为负相关关系最后,考虑到农业生产受自然环境影响的特殊性,将反响农业生产环境的“成灾面积占受灾面积的比重〞纳入解释变量体系随着农业生产技术的进步和国家农业补贴政策的改善,即使当年农业生产受灾,未必会对农村居民的消费水平造成影响,故在模型建立后,要对其系数进行显著性检验,再决定取舍综上所述,本文计量经济模型的变量选择如下:被解释变量Y——农村居民年消费水平〔元/人〕解释变量X1——农村居民年人均纯收入〔元/人〕解释变量X2——人均国内生产总值〔元/人〕解释变量X3——商品零售价格指数解释变量X4——农村恩格尔系数〔%〕解释变量X5——成灾面积占受灾面积的比重〔%〕3. 样本主要考虑数据的可得性,本文选取了1990年至2021年间的时间序列数据,一共21个样本序列,可以满足进行统计检验的根本样本数目:n>3(k+1)。
数据来源:中华人民共和国国家统计局网站及国家研究网具体数据如下:TYX1X2X3X4X51990560.00 686.30 1644.00 102.10 58.80 46.30 1991602.00 708.60 1892.76 102.90 57.60 50.10 1992688.00 784.00 2311.09 105.40 57.60 50.40 1993805.00 921.60 2998.36 113.20 58.10 47.40 19941038.00 1221.00 4044.00 121.70 58.90 57.00 19951313.00 1577.70 5045.73 114.80 58.60 48.60 19961626.00 1926.10 5845.89 106.10 56.30 45.20 19971722.00 2090.10 6420.18 100.80 55.10 56.70 19981730.00 2162.00 6796.03 97.40 53.40 50.20 19991766.00 2210.30 7158.50 97.00 52.60 53.50 20001860.00 2253.40 7857.68 98.50 49.10 62.90 20011968.95 2366.40 8621.71 99.20 47.70 60.90 20022062.27 2475.60 9398.05 98.70 46.20 57.90 20032102.72 2622.20 10541.97 99.90 45.60 59.70 20042301.00 4039.60 12335.58 102.80 47.20 43.90 20052560.00 4631.20 14053.00 100.80 45.50 51.40 20062847.00 5025.10 16154.10 101.00 43.00 59.90 20073265.00 5791.10 19524.46 103.80 43.10 51.20 20213756.00 6700.70 22698.00 105.90 43.67 55.70 20213901.00 6977.29 25607.53 98.80 40.97 45.00 20214163.33 6999.10 30015.05 103.10 41.09 49.50 4. 模型利用Eviews软件,分别绘制被解释变量与各解释变量的散点图如下:从散点图可知,解释变量X1、X2、X4与Y之间存性相关关系,而X3、X5与Y的线性关系不明显。
由以上分析和有关经济理论出发,建立多元线性回归模型为严谨起见,亦将X3、X5纳入方程,在之后的统计检验或计量经济学检验中再决定取舍利用Eviews软件进行普通最小二乘估计,初步回归结果如下:Dependent Variable: YMethod: Least SquaresDate: 01/16/13 Time: 22:46Sample: 1990 2021Included observations: 21VariableCoefficientStd. Errort-StatisticProb. X10.2473060.0998062.4778790.0256X20.0647600.0248152.6097500.0197X3-9.0962688.069187-1.1272840.2773X4-0.04531620.40007-0.0022210.9983X515.368918.2337361.8665780.0816C729.64131211.8880.6020700.5561R-squared0.983107 Mean dependent var2030.346Adjusted R-squared0.977476 S.D. dependent var1073.183S.E. of regression161.0627 Akaike info criterion13.23642Sum squared resid389117.9 Schwarz criterion13.53486Log likelihood-132.9824 Hannan-Quinn criter.13.30119F-statistic174.5896 Durbin-Watson stat0.547096Prob(F-statistic)0.0000005. 经济意义检验根据经济意义,随着成灾面积占受灾面积比重的增加,农村居民的消费水平下降。
Eviews回归的结果中,X5的系数为正,不符合经济意义当经济意义不符合时,往往是由于模型中出现了多重共线性所致6. 统计检验拟合优度检验:由回归结果可知,可决系数为0.993107,调整的可决系数为0.977476.说明方程的拟合优度较好显著性检验:除了X4和常数项之外,其他解释变量的参数均通过T检验拟合优度较好而某些参数无法通过显著性检验,更加验证了之前的猜想——模型中存在多重共线性7. 计量经济学检验及修正7.1. 多重共线性7.1.1 多重共线性检验首先计算各解释变量间的相关系数矩阵: X1X2X3X4X5X11.000000X20.9831211.000000X3-0.259363-0.2503921.000000X4-0.893935-0.8896340.5021801.000000X5-0.042090-0.028173-0.188386-0.2328281.000000由以上结果可知,X1、X2、X4之间存在高度线性相关7.1.2 用逐步回归法消除多重共线性用被解释变量对各解释变量依次进行回归,结果如下:X1:Dependent Variable: YMethod: Least SquaresDate: 01/16/13 Time: 22:48Sample: 1990 2021Included observations: 21VariableCoefficientStd. Errort-StatisticProb. X10.4943880.02214722.323490.0000C519.651181.852636.3486180.0000R-squared0.963274 Mean dependent var2030.346Adjusted R-squared0.961341 S.D. dependent var1073.183S.E. of regression211.0092 Akaike info criterion13.63207Sum squared resid845973.0 Schwarz criterion13.73155Log likelihood-141.1368 Hannan-Quinn criter.13.65366F-statistic498.3381 Durbin-Watson stat0.452734Prob(F-statistic)0.000000X2Dependent Variable: YMethod: Least SquaresDate: 01/16/13 Time: 22:49Sample: 1990 2021Included observations: 21VariableCoefficientStd. Errort-StatisticProb. X20.1302550.00573422.717510.0000C659.795875.429688.7471640.0000R-squared0.964492 Mean dependent var2030.346Adjusted R-squared0.962623 S.D. dependent var1073.183S.E. of regression207.4805 Akaike info criterion13.59834Sum squared resid817914.8 Schwarz criterion13.69782Log likelihood-140.7826 Hannan-Quinn criter.13.61993F-statistic516.0852 Durbin-Watson stat0.306836Prob(F-statistic)0.000000X3Dependent Variable: YMethod: Least SquaresDate: 01/16/13 Time: 22:49Sample: 1990 2021Included observations: 21VariableCoefficientStd. Errort-StatisticProb. X3-54.8378237.52211-1.4614800.1602C7707.1053890.9281.9807880.0623R-squared0.101057 Mean dependent var2030.346Adjusted R-squared0.053744 S.D. dependent var1073.183S.E. of regression1043.946 Akaike info criterion16.82980Sum squared resid20706645 Schwarz criterion16.92927Log likelihood-174.7129 Hannan-Quinn criter.16.85139F-statistic2.135924 Durbin-Watson stat0.109109Prob(F-statistic)0.160226X4Dependent Variable: YMethod: Least SquaresDate: 01/16/13 Time: 22:50Sample: 1990 2021Included observations: 21VariableCoefficientStd. Errort-StatisticProb. X4-150.727214.82506-10.167060.0000C9639.416754.369012.778120.0000R-squared0.844732 Mean dependent var2030.346Adjusted R-squared0.836560 S.D. dependent var1073.183S.E. of regression433.8632 Akaike info criterion15.07373Sum squared resid3576508. Schwarz criterion15.17321Log likelihood-156.2741 Hannan-Quinn criter.15.09532F-statistic103.3691 Durbin-Watson stat0.393107Prob(F-statistic)0.000000X5Dependent Variable: YMethod: Least SquaresDate: 01/16/13 Time: 22:50Sample: 1990 2021Included observations: 21VariableCoefficientStd. Errort-StatisticProb. X510.7858342.980760.2509460.8046C1463.6282271.0360.6444760.5270R-squared0.003303 Mean dependent var2030.346Adjusted R-squared-0.049154 S.D. dependent var1073.183S.E. of regression1099.242 Akaike info criterion16.93302Sum squared resid22958332 Schwarz criterion17.03250Log likelihood-175.7967 Hannan-Quinn criter.16.95461F-statistic0.062974 Durbin-Watson stat0.048747Prob(F-statistic)0.804550由以上回归结果可知,就拟合优度而言,被解释变量对解释变量X2回归的可决系数最大,因此以模型2——Y对X2的回归方程为根底,依次增加其他变量,以求得最优的回归方程。
X2、X1Dependent Variable: YMethod: Least SquaresDate: 01/16/13 Time: 23:10Sample: 1990 2021Included observations: 21VariableCoefficientStd. Errort-StatisticProb. X20.0680980.0285422.3859350.0282X10.2401200.1083992.2151470.0399C580.079577.551927.4798850.0000R-squared0.972098 Mean dependent var2030.346Adjusted R-squared0.968998 S.D. dependent var1073.183S.E. of regression188.9605 Akaike info criterion13.45252Sum squared resid642709.4 Schwarz criterion13.60173Log likelihood-138.2514 Hannan-Quinn criter.13.48490F-statistic313.5561 Durbin-Watson stat0.244955Prob(F-statistic)0.000000第一步:在初始模型中引入X1,模型拟合优度有所提高,同时在5%的显著性水平下变量也通过了显著性检验,同时估计参数的符号也符合经济学解释的预期。
X2、X1、X4 Dependent Variable: YMethod: Least SquaresDate: 01/16/13 Time: 23:15Sample: 1990 2021Included observations: 21VariableCoefficientStd. Errort-StatisticProb. X20.0602620.0258662.3298120.0324X10.1868290.1000951.8665170.0793X4-30.0638413.05553-2.3027670.0342C2343.064768.75763.0478580.0073R-squared0.978732 Mean dependent var2030.346Adjusted R-squared0.974979 S.D. dependent var1073.183S.E. of regression169.7572 Akaike info criterion13.27626Sum squared resid489897.7 Schwarz criterion13.47522Log likelihood-135.4007 Hannan-Quinn criter.13.31944F-statistic260.7734 Durbin-Watson stat0.302630Prob(F-statistic)0.000000第二步:继续引入第二个解释变量X4,模型拟合优度虽有所提高,但是变量X1的系数未能通过显著性检验,所以将X4排除模型。
X2、X1、X3Dependent Variable: YMethod: Least SquaresDate: 01/16/13 Time: 23:18Sample: 1990 2021Included observations: 21VariableCoefficientStd. Errort-StatisticProb. X20.0693810.0268312.5858850.0192X10.2261220.1021512.2136120.0408X3-12.158436.610831-1.8391680.0834C1867.984704.04712.6532090.0167R-squared0.976728 Mean dependent var2030.346Adjusted R-squared0.972622 S.D. dependent var1073.183S.E. of regression177.5735 Akaike info criterion13.36629Sum squared resid536050.0 Schwarz criterion13.56525Log likelihood-136.3460 Hannan-Quinn criter.13.40947F-statistic237.8338 Durbin-Watson stat0.345430Prob(F-statistic)0.000000第三步:去掉X4后,继续引入X3,拟合优度提高,但变量X3的系数未通过显著性检验,虽然估计参数的符号符合经济意义,也不能将X3引入模型。
X2、X1、X5Dependent Variable: YMethod: Least SquaresDate: 01/16/13 Time: 23:20Sample: 1990 2021Included observations: 21VariableCoefficientStd. Errort-StatisticProb. X20.0632500.0245392.5775100.0196X10.2601880.0932442.7904060.0126X517.386926.3579652.7346670.0141C-343.7838344.3172-0.9984510.3321R-squared0.980622 Mean dependent var2030.346Adjusted R-squared0.977203 S.D. dependent var1073.183S.E. of regression162.0376 Akaike info criterion13.18318Sum squared resid446355.1 Schwarz criterion13.38213Log likelihood-134.4234 Hannan-Quinn criter.13.22636F-statistic286.7651 Durbin-Watson stat0.642491Prob(F-statistic)0.000000第四步:去掉X3后,继续引入X5,拟合优度虽有显著提高,但常数项系数未通过显著性检验,虽然估计参数的符号符合经济意义,也不能将X5引入模型。
将上述结果总结为下表格:β0X2X1X 4X3X5R2659.79580.1302550.9644920.00000.0000580.07950.0680980.2401200.9720980.00000.02820.03992343.0640.0602620.186829-30.063840.9787320.00730.03240.07930.03421867.9840.0693810.226122-12.158430.9767280.01670.01920.04080.0834-343.78380.0632500.26018817.386920.9806220.33210.01960.01260.0141因此,回归式中只应含有X2和X1这两个解释变量消除多重共线性后,得到的最正确模型即为初始模型:Y = 0.0680982088863*X2 + 0.240120260312*X1 + 580.079486342Dependent Variable: YMethod: Least SquaresDate: 01/16/13 Time: 23:24Sample: 1990 2021Included observations: 21VariableCoefficientStd. Errort-StatisticProb. X20.0680980.0285422.3859350.0282X10.2401200.1083992.2151470.0399C580.079577.551927.4798850.0000R-squared0.972098 Mean dependent var2030.346Adjusted R-squared0.968998 S.D. dependent var1073.183S.E. of regression188.9605 Akaike info criterion13.45252Sum squared resid642709.4 Schwarz criterion13.60173Log likelihood-138.2514 Hannan-Quinn criter.13.48490F-statistic313.5561 Durbin-Watson stat0.244955Prob(F-statistic)0.0000007.2. 异方差性图示检验法首先采用图示检验法,用OLS法下得到的残差平方和X散点图初步判断具有异方差性:7.2.1 White检验在Eviews里作White检验,输出结果如下:Heteroskedasticity Test: WhiteF-statistic3.599869 Prob. F(5,15)0.0244Obs*R-squared11.45436 Prob. Chi-Square(5)0.0431Scaled explained SS2.874847 Prob. Chi-Square(5)0.7193Test Equation:Dependent Variable: RESID^2Method: Least SquaresDate: 01/17/13 Time: 11:16Sample: 1990 2021Included observations: 21VariableCoefficientStd. Errort-StatisticProb. C73231.2120974.563.4914300.0033X26.03804616.228410.3720660.7150X2^2-2.88E-050.002154-0.0133550.9895X2*X1-0.0002090.018232-0.0114660.9910X1-41.2307565.96896-0.6250020.5414X1^20.0025550.0387670.0659110.9483R-squared0.545445 Mean dependent var30605.21Adjusted R-squared0.393927 S.D. dependent var25922.32S.E. of regression20210.70 Akaike info criterion22.89780Sum squared resid6.11E+09 Schwarz criterion23.19623Log likelihood-234.4269 Hannan-Quinn criter.22.96257F-statistic3.599869 Durbin-Watson stat0.780903Prob(F-statistic)0.024428由上表可知,R2=0.545445, 卡方分布的自由度为5〔只有5项含有解释变量〕,另n=21 n*R2=11.45435. 查卡方分布表可知:当a=0.05时,卡方值为11.07,小于11.45435,拒绝原假设,即原模型随机干扰项存在异方差;而当a=0.025时,卡方值为12.8,大于11.45435,即不存在异方差。
由于拒绝原假设的卡方值与所计算的结果相差较少,因而再进行G-Q检验7.2.3 G-Q检验第一步,对变量X1取值进行升序排列第二步,构造子样本区间,建立回归模型本文案例样本容量n=21,删除中间1/4的观测值,即大约5个观测值,余下局部平分得到两个样本区间:样本一1—8和样本二14—21,样本个数分别是8个第三步,对样本一进行OLS回归,结果如下:Dependent Variable: YMethod: Least SquaresDate: 01/17/13 Time: 11:49Sample: 1 8Included observations: 8VariableCoefficientStd. Errort-StatisticProb. X10.6658410.1009976.5926620.0012X20.0471640.0307471.5339120.1856C40.9362718.975232.1573540.0835R-squared0.998792 Mean dependent var1044.250Adjusted R-squared0.998309 S.D. dependent var460.4782S.E. of regression18.93478 Akaike info criterion8.999874Sum squared resid1792.629 Schwarz criterion9.029665Log likelihood-32.99950 Hannan-Quinn criter.8.798949F-statistic2067.478 Durbin-Watson stat2.444492Prob(F-statistic)0.000000第四步,对样本进行OLS回归,结果如下:Dependent Variable: YMethod: Least SquaresDate: 01/17/13 Time: 11:50Sample: 14 21Included observations: 8VariableCoefficientStd. Errort-StatisticProb. X20.0734670.0147304.9874570.0041X10.1793970.0643222.7890580.0385C766.4955130.28765.8831050.0020R-squared0.990123 Mean dependent var3112.006Adjusted R-squared0.986172 S.D. dependent var776.1864S.E. of regression91.27424 Akaike info criterion12.14561Sum squared resid41654.94 Schwarz criterion12.17540Log likelihood-45.58244 Hannan-Quinn criter.11.94469F-statistic250.6067 Durbin-Watson stat1.636016Prob(F-statistic)0.000010第五步,计算F统计量的值。
由Sum squared resid可得,F=样本二残差平方和/样本一残差平方和=41654.94/1792.629=23.23678798第六步,判断查F分布表可知,a=0.05时,F值为10.97,小于23.23678798,故拒绝原假设,即原回归方程中存在异方差加权最小二乘估计消除异方差以残差平方根的倒数为权重进行加权最小二乘估计,结果如下:Dependent Variable: YMethod: Least SquaresDate: 01/17/13 Time: 12:07Sample: 1 21Included observations: 21Weighting series: 1/SQR(E2)Weight type: Inverse standard deviation (EViews default scaling)White heteroskedasticity-consistent standard errors & covarianceVariableCoefficientStd. Errort-StatisticProb. X20.0690930.0183133.7727910.0014X10.2339780.0632893.6969510.0016C593.306710.9525554.170640.0000Weighted StatisticsR-squared0.998523 Mean dependent var2271.864Adjusted R-squared0.998359 S.D. dependent var3223.489S.E. of regression73.69753 Akaike info criterion11.56938Sum squared resid97763.87 Schwarz criterion11.71860Log likelihood-118.4785 Hannan-Quinn criter.11.60176F-statistic6086.397 Durbin-Watson stat0.774687Prob(F-statistic)0.000000 Weighted mean dep.1955.434Unweighted StatisticsR-squared0.972051 Mean dependent var2030.346Adjusted R-squared0.968945 S.D. dependent var1073.183S.E. of regression189.1204 Sum squared resid643797.2Durbin-Watson stat0.241928可以发现,经过异方差修正的模型可决系数从0.972051提高到0.998523,而AIC和SC值又显著下降。
对修正过的模型再次进行异方差检验〔White检验〕,结果如下:Heteroskedasticity Test: WhiteF-statistic31.71963 Prob. F(6,14)0.0000Obs*R-squared19.56107 Prob. Chi-Square(6)0.0033Scaled explained SS0.506804 Prob. Chi-Square(6)0.9978修正过的模型通过了White检验,修正异方差之后的模型为:Y = 0.0690926108804*X2 + 0.233977931246*X1 + 593.3066871457.3. 序列相关性图示检验法利用Eviews作残差图如下:如下图,残差的变动有系统模式,连续为正和连续为负,说明残差项存在一阶正自相关,需要采取补救措施杜宾分析法上述经过异方差修正的回归模型中,杜宾统计量D.W.=0.241928. 查表可知,当k=3, n=21,上下界为5% 时,dL=1.13,dU=1.54,0