# st: xtlogit missing information

 From Marie Olson To Stata Subject st: xtlogit missing information Date Thu, 07 Nov 2002 13:52:42 -0500

```Does anyone know why xtlogit would produce coefficients for all
variables in an analysis, but fail to produce standard errors, etc. for
the constant or other variables in the model?  I have included two
examples below:
xtlogit epc dpc, nolog

bivariate model where dpc is the occurrence of policy change, outcome is
occurrence of violence:
Random-effects logit                            Number of obs
=      1198
Group variable (i) : ccode                      Number of groups
=        30

Random effects u_i ~ Gaussian                   Obs per group: min
=        26
avg
=      39.9
max
=        41

Wald chi2(1)       =
21.66
Log likelihood  = -384.59828                    Prob > chi2        =
0.0000

------------------------------------------------------------------------------

epc |      Coef.   Std. Err.      z    P>|z|     [95% Conf.
Interval]
-------------+----------------------------------------------------------------

dpc |   1.316804   .2829592     4.65   0.000     .7622141
1.871394
_cons |  -1.565715          .        .       .
.           .
-------------+----------------------------------------------------------------

/lnsig2u |   .8472979          .
.           .
-------------+----------------------------------------------------------------

sigma_u |   1.527525          .
.           .
rho |   .4149475          .
.           .
------------------------------------------------------------------------------

Likelihood ratio test of rho=0: chibar2(01) =   376.44 Prob >= chibar2 =
0.000

Or a multivariate model, where posdpc is the occurrence of policy
change, epc is the occurrence of violence, regimesc is a regime score
(-10 to 10), and peace is the number of years of peace prior to current
year:
xtlogit epc posdpc regimesc, nolog

Random-effects logit                            Number of obs
=       863
Group variable (i) : ccode                      Number of groups
=        24

Random effects u_i ~ Gaussian                   Obs per group: min
=         9
avg
=      36.0
max
=        41

Wald chi2(2)       =
28.67
Log likelihood  = -260.13778                    Prob > chi2        =
0.0000

------------------------------------------------------------------------------

epc |      Coef.   Std. Err.      z    P>|z|     [95% Conf.
Interval]
-------------+----------------------------------------------------------------

posdpc |   1.686509   .4461846     3.78   0.000      .812003
2.561014
regimesc |   .0650246   .0198366     3.28   0.001     .0261455
.1039037
_cons |  -1.783155   .2400833    -7.43   0.000    -2.253709
-1.3126
-------------+----------------------------------------------------------------

/lnsig2u |   1.527534   .1884778                      1.158124
1.896943
-------------+----------------------------------------------------------------

sigma_u |   2.146346   .2022693                      1.784364
2.581761
rho |   .5833854   .0139242                      .4918199
.6695379
------------------------------------------------------------------------------

Likelihood ratio test of rho=0: chibar2(01) =   296.92 Prob >= chibar2 =
0.000

Thanks!
Marie

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
```