What are the techniques for dealing with complete separation or quasi-complete separation?
Now we have some understanding of what complete or quasi-complete separation is, an immediate question is what the techniques are for dealing with the issue. We will give a general and brief description about a few techniques for dealing with the issue with illustration sample code in SAS. Note that these techniques may be available in other packages, for example, Stata’s user written firthlogit command. Let’s say that the predictor variable involved in complete quasi-complete separation is called X. • In the case of complete separation, make sure that we are not using the dichotomous version of the outcome variable. • If it is quasi-complete separation, the easiest strategy is the “Do nothing” strategy. This is because that the maximum likelihood for other predictor variables are still valid. The drawback is that we don’t get any reasonable estimate for the variable X that actually predicts the outcome variable effectively. This strategy does not work well for the situation of complet
Related Questions
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