Thanks for your feedback, Steve. I meant to say that I had already tried random _residual_/group=Sex, and weirdly, Glimmix ignored the statement altogether by not estimating the inflation factors and by making no warning or other statement in the LOG about ignoring the statement. However, your suggestion of adding covtest did the trick. So I used: random _residual_/group=Sex; covtest homogeneity/cl(alpha=0.1); ods output covparms=cov; The cov dataset had the inflation factors and their standard errors and confidence limits. I tried to get a single inflation factor by dropping off the group=Sex, but it didn't work, and again there was no indication of why in the LOG. So I tricked it by making a dummy class variable that had the same value for every observation in the data set, then using random _residual_/group=Dummy. It worked perfectly. But it seems to me that something needs to be done to Proc Glimmix and to its documentation so others don't have this problem. I also tried the analysis with Proc Genmod, as you suggested, but it gave a different value for the scale parameter, way too large, and squaring it didn't make it right. Maybe it was because I actually have under-dispersion with these data, but the values given by Glimmix were correct, because they were exactly the same as the variance divided by the mean for the males and for the females. So again, THANK YOU!
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