连老师
我们在分析消费与收入的协整关系问题,参考国内学者的研究时,对二者的分析认为消费与收入分别存在一阶单整关系,二者存在一个协整关系。但我们做的结果却没找到协整关系,以下是我们做的结果:
cu:为城镇人均消费支出 yu:城镇人均可支配收入(两类数据均采用当年价,时间为1978~2009年)
. dfuller cu
Dickey-Fuller test for unit root Number of obs = 31
---------- Interpolated Dickey-Fuller ---------
Test 1% Critical 5% Critical 10% Critical
Statistic Value Value Value
------------------------------------------------------------------------------
Z(t) 9.600 -3.709 -2.983 -2.623
------------------------------------------------------------------------------
MacKinnon approximate p-value for Z(t) = 1.0000
. dfuller cu,lag(2)
Augmented Dickey-Fuller test for unit root Number of obs = 29
---------- Interpolated Dickey-Fuller ---------
Test 1% Critical 5% Critical 10% Critical
Statistic Value Value Value
------------------------------------------------------------------------------
Z(t) 2.371 -3.723 -2.989 -2.625
------------------------------------------------------------------------------
MacKinnon approximate p-value for Z(t) = 0.9990
. dfuller cu,lag(3)
Augmented Dickey-Fuller test for unit root Number of obs = 28
---------- Interpolated Dickey-Fuller ---------
Test 1% Critical 5% Critical 10% Critical
Statistic Value Value Value
------------------------------------------------------------------------------
Z(t) 2.444 -3.730 -2.992 -2.626
------------------------------------------------------------------------------
MacKinnon approximate p-value for Z(t) = 0.9990
. dfuller lncu
Dickey-Fuller test for unit root Number of obs = 31
---------- Interpolated Dickey-Fuller ---------
Test 1% Critical 5% Critical 10% Critical
Statistic Value Value Value
------------------------------------------------------------------------------
Z(t) -0.957 -3.709 -2.983 -2.623
------------------------------------------------------------------------------
MacKinnon approximate p-value for Z(t) = 0.7687
. dfuller lncu,lag(2)
Augmented Dickey-Fuller test for unit root Number of obs = 29
---------- Interpolated Dickey-Fuller ---------
Test 1% Critical 5% Critical 10% Critical
Statistic Value Value Value
------------------------------------------------------------------------------
Z(t) -0.702 -3.723 -2.989 -2.625
------------------------------------------------------------------------------
MacKinnon approximate p-value for Z(t) = 0.8464
. dfuller lncu,lag(3)
Augmented Dickey-Fuller test for unit root Number of obs = 28
---------- Interpolated Dickey-Fuller ---------
Test 1% Critical 5% Critical 10% Critical
Statistic Value Value Value
------------------------------------------------------------------------------
Z(t) -0.891 -3.730 -2.992 -2.626
------------------------------------------------------------------------------
MacKinnon approximate p-value for Z(t) = 0.7909
结果显示不存在单位根
dfuller lnyu
Dickey-Fuller test for unit root Number of obs = 31
---------- Interpolated Dickey-Fuller ---------
Test 1% Critical 5% Critical 10% Critical
Statistic Value Value Value
------------------------------------------------------------------------------
Z(t) -0.738 -3.709 -2.983 -2.623
------------------------------------------------------------------------------
MacKinnon approximate p-value for Z(t) = 0.8367
. dfuller lnyu,lag(2)
Augmented Dickey-Fuller test for unit root Number of obs = 29
---------- Interpolated Dickey-Fuller ---------
Test 1% Critical 5% Critical 10% Critical
Statistic Value Value Value
------------------------------------------------------------------------------
Z(t) -0.396 -3.723 -2.989 -2.625
------------------------------------------------------------------------------
MacKinnon approximate p-value for Z(t) = 0.9108
dfuller lnyu
Dickey-Fuller test for unit root Number of obs = 31
---------- Interpolated Dickey-Fuller ---------
Test 1% Critical 5% Critical 10% Critical
Statistic Value Value Value
------------------------------------------------------------------------------
Z(t) -0.738 -3.709 -2.983 -2.623
------------------------------------------------------------------------------
MacKinnon approximate p-value for Z(t) = 0.8367
. dfuller lnyu,lag(2)
Augmented Dickey-Fuller test for unit root Number of obs = 29
---------- Interpolated Dickey-Fuller ---------
Test 1% Critical 5% Critical 10% Critical
Statistic Value Value Value
------------------------------------------------------------------------------
Z(t) -0.396 -3.723 -2.989 -2.625
------------------------------------------------------------------------------
MacKinnon approximate p-value for Z(t) = 0.9108
人均可支配收入也不存在单位根。
现在很困惑问题出在哪里?我们采用的数据来自于国家统计局网站上历年城乡人均消费、支出数据。