13# 蓝色
版主你看 为什么这三个不同命令主要结果一样 ,只是地区虚拟变量那不同?
xtset district year
panel variable: district (strongly balanced)
time variable: year, 1 to 5
delta: 1 unit
.
xtreg var8 ti var4 a b,fe
Fixed-effects (within) regression Number of obs = 660
Group variable: district Number of groups = 132
R-sq: within = 0.5911 Obs per group: min = 5
between = 0.7004 avg = 5.0
overall = 0.6042 max = 5
F(4,524) = 189.37
corr(u_i, Xb) = 0.3915 Prob > F = 0.0000
------------------------------------------------------------------------------
var8 |
Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
ti | -242.4167 19.49112 -12.44 0.000 -280.707 -204.1263
var4 | 81.53912 24.10555 3.38 0.001 34.18373 128.8945
a | .0333506 .0027825 11.99 0.000 .0278843 .0388168
b | .015245 .0025494 5.98 0.000 .0102367 .0202532
_cons | 197.9695 6.647092 29.78 0.000 184.9112 211.0277
-------------+----------------------------------------------------------------
sigma_u | 159.92436
sigma_e | 108.00245
rho | .68677695 (fraction of variance due to u_i)
------------------------------------------------------------------------------
. xi:xtreg var8 ti var4 a b i.district,fe
i.district _Idistrict_1-132 (naturally coded; _Idistrict_1 omitted)
Fixed-effects (within) regression Number of obs = 660
Group variable: district Number of groups = 132
R-sq: within = 0.5911 Obs per group: min = 5
between = 0.7004 avg = 5.0
overall = 0.6042 max = 5
F(4,524) = 189.37
corr(u_i, Xb) = 0.3915 Prob > F = 0.0000
------------------------------------------------------------------------------
var8 |
Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
ti | -242.4167 19.49112 -12.44 0.000 -280.707 -204.1263
var4 | 81.53912 24.10555 3.38 0.001 34.18373 128.8945
a | .0333506 .0027825 11.99 0.000 .0278843 .0388168
b | .015245 .0025494 5.98 0.000 .0102367 .0202532
_Idistrict_2 | (dropped)
_Idistrict_3 | (dropped)
_Idistrict_4 | (dropped)
_Idistrict_5 | (dropped)
_Idistrict_6 | (dropped)
_Idistrict_7 | (dropped)
_Idistrict_8 | (dropped)
--more--
. xi:xtreg var8 ti var4 a b i.district,re
i.district _Idistrict_1-132 (naturally coded; _Idistrict_1 omitted)
Random-effects GLS regression Number of obs = 660
Group variable: district Number of groups = 132
R-sq: within = 0.5911 Obs per group: min = 5
between = 1.0000 avg = 5.0
overall = 0.8808 max = 5
Random effects u_i ~ Gaussian Wald chi2(135) = 3871.97
corr(u_i, X) = 0 (assumed) Prob > chi2 = 0.0000
------------------------------------------------------------------------------
var8 |
Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
ti | -242.4167 19.49112 -12.44 0.000 -280.6185 -204.2148
var4 | 81.53912 24.10555 3.38 0.001 34.29311 128.7851
a | .0333506 .0027825 11.99 0.000 .027897 .0388041
b | .015245 .0025494 5.98 0.000 .0102483 .0202416
_
Idistrict_2 | 17.75247 68.3175 0.26 0.795 -116.1474 151.6523
_Idistrict_3 | 51.38357 69.76842 0.74 0.461 -85.36002 188.1272
_Idistrict_4 | 164.425 68.77937 2.39 0.017 29.61995 299.2301
_Idistrict_5 | 45.44195 69.73088 0.65 0.515 -91.22807 182.112
_Idistrict_6 | 25.87626 69.72691 0.37 0.711 -110.786 162.5385
_Idistrict_7 | -7.751544 69.92745 -0.11 0.912 -144.8068 129.3037
_Idistrict_8 | 94.96308 69.89578 1.36 0.174 -42.03012 231.9563