panel数据做了豪斯曼检验和BP检验,都通过了,怎么选用固定效应还是随机效应模型呢?模型结果如下:
. xtreg lnintery lnv213 lnv210 lnf5 lnf349 lnguoyou lnwaizi lncout, fe
Fixed-effects (within) regression Number of obs = 70464
Group variable: sample Number of groups = 23488
R-sq: within = 0.6612 Obs per group: min = 3
between = 0.1745 avg = 3.0
overall = 0.2357 max = 3
F(7,46969) = 13095.35
corr(u_i, Xb) = -0.4442 Prob > F = 0.0000
------------------------------------------------------------------------------
lnintery | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
lnv213 | .0143416 .0004146 34.59 0.000 .013529 .0151543
lnv210 | -.7807843 .0047838 -163.22 0.000 -.7901605 -.771408
lnf5 | .006831 .0013178 5.18 0.000 .0042481 .009414
lnf349 | .1579713 .0033602 47.01 0.000 .1513853 .1645573
lnguoyou | .0021027 .0126293 0.17 0.868 -.0226508 .0268563
lnwaizi | -.0271663 .0128926 -2.11 0.035 -.052436 -.0018966
lncout | .6994367 .0027664 252.83 0.000 .6940145 .704859
_cons | 2.731985 .0272669 100.19 0.000 2.678541 2.785428
-------------+----------------------------------------------------------------
sigma_u | .96921087
sigma_e | .32330252
rho | .89987058 (fraction of variance due to u_i)
------------------------------------------------------------------------------
F test that all u_i=0: F(23487, 46969) = 15.28 Prob > F = 0.0000
. est store fe
. xtreg lnintery lnv213 lnv210 lnf5 lnf349 lnguoyou lnwaizi lncout, re
Random-effects GLS regression Number of obs = 70464
Group variable: sample Number of groups = 23488
R-sq: within = 0.6270 Obs per group: min = 3
between = 0.2657 avg = 3.0
overall = 0.3273 max = 3
Random effects u_i ~ Gaussian Wald chi2(7) = 78582.47
corr(u_i, X) = 0 (assumed) Prob > chi2 = 0.0000
------------------------------------------------------------------------------
lnintery | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
lnv213 | .0153222 .0004418 34.68 0.000 .0144562 .0161882
lnv210 | -.7055055 .0043463 -162.32 0.000 -.7140242 -.6969869
lnf5 | .0368264 .0013172 27.96 0.000 .0342447 .039408
lnf349 | .3083644 .0034798 88.62 0.000 .3015442 .3151847
lnguoyou | -.0843309 .0130275 -6.47 0.000 -.1098643 -.0587975
lnwaizi | -.1320997 .0132531 -9.97 0.000 -.1580753 -.1061242
lncout | .6068603 .0027685 219.20 0.000 .6014341 .6122865
_cons | 1.032505 .0216639 47.66 0.000 .9900448 1.074966
-------------+----------------------------------------------------------------
sigma_u | .6323744
sigma_e | .32330252
rho | .79278354 (fraction of variance due to u_i)
------------------------------------------------------------------------------
. est store re
. hausman fe
---- Coefficients ----
| (b) (B) (b-B) sqrt(diag(V_b-V_B))
| fe re Difference S.E.
-------------+----------------------------------------------------------------
lnv213 | .0143416 .0153222 -.0009805 .
lnv210 | -.7807843 -.7055055 -.0752787 .0019984
lnf5 | .006831 .0368264 -.0299953 .0000415
lnf349 | .1579713 .3083644 -.1503932 .
lnguoyou | .0021027 -.0843309 .0864336 .
lnwaizi | -.0271663 -.1320997 .1049334 .
lncout | .6994367 .6068603 .0925765 .
------------------------------------------------------------------------------
b = consistent under Ho and Ha; obtained from xtreg
B = inconsistent under Ha, efficient under Ho; obtained from xtreg
Test: Ho: difference in coefficients not systematic
chi2(7) = (b-B)'[(V_b-V_B)^(-1)](b-B)
= 41875.75
Prob>chi2 = 0.0000
(V_b-V_B is not positive definite)