ywh19860616 发表于 2014-1-2 13:58
请上传示例数据,才能知道什么问题。
我是26个制造业行业,分轻、重两个大行业,设置虚拟变量,按照轻重行业划分标准赋值,用stata设置了两列,he1和he2。用命令:xtreg y x1 x2 x3 year2-year14 he1,fe r进行回归,但回归结果he1系数为0,而且这个变量有没有不影响其他变量的系数值与显著性,这样对不对?he1与he2加一个,或都加上,结果都一样。这是怎么回事
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| Robust
y | Coef. Std. Err. t P>|t| [95% Conf. Interval]
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lncomo | .0644998 .1116604 0.58 0.569 -.165469 .2944686
lnpfa | .5459981 .1388883 3.93 0.001 .2599523 .8320438
lnrd | .0473482 .0342663 1.38 0.179 -.0232246 .1179209
hr | 1.209543 .1979712 6.11 0.000 .8018135 1.617272
year2 | .0580555 .0202559 2.87 0.008 .0163377 .0997733
year3 | .1177069 .0338592 3.48 0.002 .0479726 .1874412
year4 | .1621521 .0403136 4.02 0.000 .0791247 .2451794
year5 | .2249938 .048558 4.63 0.000 .1249868 .3250009
year6 | .2990771 .0718677 4.16 0.000 .1510627 .4470915
year7 | .2837223 .1062775 2.67 0.013 .0648397 .5026048
year8 | .2938303 .1202504 2.44 0.022 .04617 .5414905
year9 | .2582952 .1446028 1.79 0.086 -.0395198 .5561102
year10 | .209554 .1698464 1.23 0.229 -.1402512 .5593591
year11 | .0371362 .2032027 0.18 0.856 -.3813677 .45564
year12 | -.0387406 .2154763 -0.18 0.859 -.4825223 .4050412
year13 | -.2205801 .2541894 -0.87 0.394 -.7440929 .3029327
year14 | -.5650926 .3208306 -1.76 0.090 -1.225856 .0956704
he1 | 0 (omitted)
_cons | -.9537756 .2109916 -4.52 0.000 -1.388321 -.5192303
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sigma_u | .50768503
sigma_e | .11497452
rho | .95121426 (fraction of variance due to u_i)
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