st: separation problem

["Matthew Henry Kroenig" <kroenig@uclink.berkeley.edu>]

Hi,

I am doing logit analysis and I have a separation problem--one of my model's covariates perfectly 
predicts the binary outcome.  Stata ommits the variable and drops observations when separation is 
present.  According to Christopher Zorn [ "A Solution to Separation in Binary Response Models" 
Political Analysis, 13:2 (2005)], I can solve the separation problem by estimating a 
penalized-likelihood model using, for example, Firth's bias-reduced logistic regression (brlr). 
As far as I can tell, Firth's own brlr package is for R only.  Is there a version of brlr for 
Stata?  How can I estimate a penalized-likelihood model in Stata?

Thanks in advance for your time.

Best,

Matt Kroenig
  
National Science Foundation IGERT Fellow
Department of Political Science
210 Barrows Hall
UC Berkeley
Berkeley, CA 94720
USA

(510) 499-1575
kroenig@berkeley.edu
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