st: problem with Margin command and interaction graph in fixed effect logistic regression

[Nahla Betelmal <nahlaib@gmail.com>]

Dear Statalist members,

I am facing difficulty in getting the margins and plotting the
interaction graph in a fixed-effect logistic regression. I believe
this is due to the fact that fixed effect logistic regression does not
report an intercept. I wonder if there is a way to get around this to
produce the graph.

In the regression there is three interactions ( Dummy variable with
Continuous variable in each interaction)


Conditional (fixed-effects) logistic regression   Number of obs   =       9941

           Wald chi2(34)   =     681.92

         Prob > chi2     =     0.0000
Log pseudolikelihood = -3651.0306                               Pseudo
R2       =     0.1458

                                              (Std. Err. adjusted for
1220 clusters in firm)
---------------------------------------------------------------------------------------------
                            |               Robust
                         To |      Coef.   Std. Err.      z    P>|z|
  [95% Conf. Interval]
----------------------------+----------------------------------------------------------------
                   1.DV |   .1529853   .1576329     0.97   0.332
-.1559694    .4619401
                            |
            DVr#c.IVA |
                         0  |   .1643871   .0829615     1.98   0.048
  .0017855    .3269886
                         1  |   .2475583    .091258     2.71   0.007
   .068696    .4264206
                            |
            DV#c.IVB |
                         0  |   .1423918   .1179659     1.21   0.227
  -.088817    .3736007
                         1  |   .4909195   .1660735     2.96   0.003
  .1654214    .8164176
                            |
           DVr#c.IVC |
                         0  |   .5103285    .104731     4.87   0.000
  .3050596    .7155974
                         1  |   .5350398   .1325409     4.04   0.000
  .2752644    .7948152


I tried to get each interaction alone first, but did not work

. margins DV, at( IVA=(-1.1(0.1)1.7))
default predict option not appropriate with margins
r(322);


I tried all together

. margins OC_2year, at((mean) IVA (mean) IVB (mean) IVC)
default predict option not appropriate with margins
r(322);


Many thanks in advance

Nahla Betelmal
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