st: problem using mfx, pred(pu0) after clogit

[Samia Costa <samia.costa@unisg.ch>]

Dear all,

I am using Stata 10.1 and I have been trying to obtain marginal effects after clogit using mfx with the predict(pu0) option. However, when I run the mfx command, I get an output as follows:

. mfx, pred(pu0)

warning: predict() expression pu0 unsuitable for standard-error calculation;
option nose imposed


Marginal effects after clogit
      y  = Pr(response|fixed effect is 0) (predict, pu0)
         =  2.575e-69
-------------------------------------------------------------------------------
                      variable |          dy/dx                 X
---------------------------------+---------------------------------------------
                            x1 |               .            3.44053
                  	    x2*|        1.99e-69            .108374
                     	    x3 |               .            1.47502
-------------------------------------------------------------------------------
(*) dy/dx is for discrete change of dummy variable from 0 to 1


I can easily obtain the marginal effects after logit or xtlogit, re. Is there any other way I could obtain the marginal effects? The equation I estimate is

xi:clogit y x1 x2 x3 i.year i.dis, group(number) robust cluster(number)

Thanks in advance for all the help!

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