Agree with the post from @StatDave . I will add on that one of the reasons people sometimes use an identity link to model binary response data is that you are directly modeling the probability of the event. That is, the model coefficients can be interpreted as estimates of the difference in the probability of the event. Whereas, for the logit link, you are modeling the log odds of the event. The model coefficients are therefore estimates of log odds ratios, and some people find log odds ratios hard to interpret.  ... View more