I am estimating the ICC for an outcome with data on several 10,000s nested within ~50 groups. The outcome of interest is binary with prevalence ~5%. I am using:
Code:
melogit y || group:
estat icc
From the model, the variance associated with the level 2 unit (-var(_cons)-) is low (<.001) with lb95 < 0.00001 and ub95 4.61e+11. This does not make sense, but the underlying data included in the model have been double and triple checked. Furthermore, the point estimate and SE of ICC is very low, with a CI ranging from <.00001 to 1. I wonder if anyone can offer an explanation or suggest an alternative strategy. I have tried to use the option - normal-:
Code:
melogit y || group:
estat icc, normal
The CI becomes way more narrow, but the lower bound is slightly negative, and imposing the normal option strikes me as a violation as the outcome is binary.