哪位高手能指导下:pcc_w和ice_w 这两个变量明明一个显著,一个不显著,为何回归系数T检验做出来的两个回归系数是无显著关异的呢?先谢谢!
Fixed-effects (within) regression Number of obs = 5895
Group variable: stkcd Number of groups = 1788
R-sq: within = 0.1267 Obs per group: min = 1
between = 0.0354 avg = 3.3
overall = 0.0701 max = 5
F(12,4095) = 49.50
corr(u_i, Xb) = -0.0685 Prob > F = 0.0000
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cod_w1 | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
pcc_w | -.0015119 .0014119 -1.07 0.284 -.0042799 .0012561
ice_w | -.0004329 .0001213 -3.57 0.000 -.0006706 -.0001952
lnasset_w | -.0004305 .0009089 -0.47 0.636 -.0022123 .0013514
|
year |
2008 | -.0149275 .0009138 -16.34 0.000 -.0167189 -.013136
2009 | -.0169472 .0008397 -20.18 0.000 -.0185935 -.0153008
2010 | -.0099045 .0009182 -10.79 0.000 -.0117047 -.0081044
2011 | -.0083803 .0010231 -8.19 0.000 -.0103862 -.0063745
|
debt_w | .0094323 .0026012 3.63 0.000 .0043325 .0145321
state | .0049503 .0023951 2.07 0.039 .0002546 .0096461
first1_w | -.0259855 .0065295 -3.98 0.000 -.0387869 -.0131841
first2_9_w | -.0209887 .0057084 -3.68 0.000 -.0321802 -.0097972
dudongbili_w | .0077536 .008841 0.88 0.381 -.0095795 .0250868
_cons | .0691274 .0186749 3.70 0.000 .0325145 .1057403
-------------+----------------------------------------------------------------
sigma_u | .02208744
sigma_e | .01733454
rho | .61883737 (fraction of variance due to u_i)
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F test that all u_i=0: F(1787, 4095) = 3.99 Prob > F = 0.0000
.
. test pcc_w=ice_w
( 1) pcc_w - ice_w = 0
F( 1, 4095) = 0.56
Prob > F = 0.4538