我的计量基础很差,最近做毕业论文时遇到了很大的问题,想请各位高手予以指点:
我是要根据一组面板数据做一个probit或者logit回归,首先对这些指标进行过corr,相关系数大多都在0.1以内,少数几个在0.5以下,做VIF分析,也都在2一下,是不是可以不考虑共线性了呢?
但是回归的结果感觉不大好,大多数系数的z值都很小,而且其它相关指标我的理解也很模糊,这两天虽然一直在网上查阅相关资料,但总还是看得云里雾里的。先贴一个试验结果发上来:
Fitting comparison model:
Iteration 0: log likelihood = -198.93324
Iteration 1: log likelihood = -89.5573
Iteration 2: log likelihood = -71.344916
Iteration 3: log likelihood = -67.369216
Iteration 4: log likelihood = -66.924545
Iteration 5: log likelihood = -66.917215
Iteration 6: log likelihood = -66.917213
Fitting full model:
rho = 0.0 log likelihood = -92.512473
rho = 0.1 log likelihood = -55.467123
rho = 0.2 log likelihood = -41.736322
rho = 0.3 log likelihood = -33.637198
rho = 0.4 log likelihood = -27.967127
rho = 0.5 log likelihood = -23.714651
rho = 0.6 log likelihood = -20.197696
rho = 0.7 log likelihood = -17.289147
rho = 0.8 log likelihood = -14.803667
Iteration 0: log likelihood = -16.824675
Iteration 1: log likelihood = -13.217479
Iteration 2: log likelihood = -12.605991
Iteration 3: log likelihood = -12.587627
Iteration 4: log likelihood = -12.587611
Iteration 5: log likelihood = -12.587611
Random-effects probit regression Number of obs = 287
Group variable (i): country Number of groups = 13
Random effects u_i ~ Gaussian Obs per group: min = 15
avg = 22.1
max = 24
Wald chi2(11) = 7.91
Log likelihood = -12.587611 Prob > chi2 = 0.7214
------------------------------------------------------------------------------
y | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
rer | -3.475526 3.158579 -1.10 0.271 -9.666228 2.715176
res_g | .825807 1.651825 0.50 0.617 -2.411711 4.063325
m2_res | .9094768 2.506475 0.36 0.717 -4.003125 5.822078
m2_res_g | 1.246309 1.961459 0.64 0.525 -2.59808 5.090698
gdp_g | 1.384571 1.648769 0.84 0.401 -1.846958 4.616099
dc_gdp | 3.991885 2.858283 1.40 0.163 -1.610247 9.594017
ca_gdp | -7.376085 3.668452 -2.01 0.044 -14.56612 -.1860506
rl_rd | -1.043828 2.217364 -0.47 0.638 -5.389782 3.302125
exp_g | -.5325338 1.768384 -0.30 0.763 -3.998502 2.933435
im_g | .6575589 1.705087 0.39 0.700 -2.684351 3.999469
inf | .2479812 1.57941 0.16 0.875 -2.847606 3.343568
-------------+----------------------------------------------------------------
/lnsig2u | 2.113526 .4843254 1.164265 3.062786
-------------+----------------------------------------------------------------
sigma_u | 2.877043 .6967125 1.789852 4.624615
rho | .8922109 .0465779 .7621069 .9553313
------------------------------------------------------------------------------
Likelihood-ratio test of rho=0: chibar2(01) = 108.66 Prob >= chibar2 = 0.000
想请各位给我指点一下: 1、 Log likelihood = -12.587611 Wald chi2(11) Prob > chi2 = 0.7214
/lnsig2u sigma_u rho |
Likelihood-ratio test of rho=0: chibar2(01) = 108.66 Prob >= chibar2 = 0.000
这些检验都应该怎么去看?
2、像这种表现不好的模型可以从哪些方面改进呢?或者说其问题可能出在哪里了呢?
快答辩了,可是这个实证困扰我很久了,真头大~~
期盼您的解答,不胜感激!!!