SpencerMeng 发表于 2014-9-24 12:12 
前辈不敢当,我也是摸索着学习。
我没用xtptm程序,我用的是连老师的。
大神,我用的也是连老师的程序,但我的三重门槛跑出的结果异常,------------------------------------------------------------------------------
lnscore | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
patent2 | .0407027 .0056751 7.17 0.000 .0295452 .0518602
three | .0137706 .0030825 4.47 0.000 .0077104 .0198308
lngdp | .728314 .1109646 6.56 0.000 .5101538 .9464743
city | -.0316464 .0112927 -2.80 0.005 -.0538482 -.0094446
city3 | -.0020575 .012004 -0.17 0.864 -.0256578 .0215428
people2_1 | -.0409417 .0027367 -14.96 0.000 -.0463222 -.0355612
people2_2 | -.0155329 .0014306 -10.86 0.000 -.0183454 -.0127203
people2_3 | 0 (omitted)
people2_4 | -.0086291 .0014964 -5.77 0.000 -.011571 -.0056871
_cons | 1.434257 .4037603 3.55 0.000 .6404499 2.228063
-------------+----------------------------------------------------------------
sigma_u | .41366473
sigma_e | .22548517
rho | .77093581 (fraction of variance due to u_i)
------------------------------------------------------------------------------
F test that all u_i=0: F(19, 392) = 14.21 Prob > F = 0.0000
Note: people2_1: people2*I(people2<32.83)
people2_2: people2*I(32.83<=people2<32.83)
people2_3: people2*I(32.83<=people2<83.29000000000001)
people2_4: people2*I(people2>=83.29000000000001)
可以看出 people2_3被剔除了,而且people2_2: people2*I(32.83<=people2<32.83)也很怪,根本没有按照程序跑出的门槛值来划分,请问你知道这是哪里出了问题吗?不胜感激!!!