xtreg y x1 x2 x3,fe
estimates store FE
xtreg y x1 x2 x3,re
estimates store RE
hausman FE RE,constant sigmamore
得出我的面板数据的P值为0.0000,所以应该使用固定效应模型,但下文又提到“然而......如果聚类稳健标准误与普通标准误相差较大(在本例中,二者约相差一倍),则传统的豪斯曼检验不适用。"于是我想算一算普通标准误和聚类稳健标准误,又按照书中输入了:
reg x1 x2 x3,vce(cluster id)
reg x1 x2 x3
得出了:
. reg x1 x2 x3,vce(cluster id)
Linear regression Number of obs = 540
F(2, 53) = 10.62
Prob > F = 0.0001
R-squared = 0.7247
Root MSE = 2.4e+11
(Std. Err. adjusted for 54 clusters in id)
------------------------------------------------------------------------------
| Robust
x1 | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
x2 | 3.63e+09 1.19e+09 3.04 0.004 1.24e+09 6.03e+09
x3 | 3037.495 785.6851 3.87 0.000 1461.61 4613.38
_cons | -5.54e+10 1.76e+10 -3.15 0.003 -9.07e+10 -2.01e+10
------------------------------------------------------------------------------
.
. reg x1 x2 x3
Source | SS df MS Number of obs = 540
-------------+---------------------------------- F(2, 537) = 706.94
Model | 8.0365e+25 2 4.0182e+25 Prob > F = 0.0000
Residual | 3.0523e+25 537 5.6840e+22 R-squared = 0.7247
-------------+---------------------------------- Adj R-squared = 0.7237
Total | 1.1089e+26 539 2.0573e+23 Root MSE = 2.4e+11
------------------------------------------------------------------------------
x1 | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
x2 | 3.63e+09 1.46e+09 2.49 0.013 7.71e+08 6.49e+09
x3 | 3037.495 92.96918 32.67 0.000 2854.867 3220.123
_cons | -5.54e+10 2.16e+10 -2.57 0.010 -9.78e+10 -1.31e+10
------------------------------------------------------------------------------
但是由于我基础知识不太清楚,请问哪个值是普通标准误,哪个值是聚类稳健标准误呢?请指教。
由于找了很久资料都没有这样的说明,于是我暂且跳过了这个步骤,根据老师给的数据输入了以下指令
xtabond2 y l.y x1 x2 x3 x2006-x2015, gmm(l.y) iv(x1 x2 x3) nolevel twostep robust
但是得出来的值都很小:
Arellano-Bond test for AR(1) in first differences: z = -1.08 Pr > z = 0.278
Arellano-Bond test for AR(2) in first differences: z = -1.83 Pr > z = 0.067
------------------------------------------------------------------------------
Sargan test of overid. restrictions: chi2(25) = 240.08 Prob > chi2 = 0.000
(Not robust, but not weakened by many instruments.)
Hansen test of overid. restrictions: chi2(25) = 36.63 Prob > chi2 = 0.063
(Robust, but weakened by many instruments.)
老师说让我把所有变量取对数,我做了之后Sargan值稍微变大了一点,但还是小于0.1。我想问为什么要取对数呢?
在知网上搜了很多使用GMM动态面板的论文,但学者们都是直接给结论,没有过程。是我的搜索方式不对吗?请问有什么推荐吗?


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