Trying to run a GMM and introduce one covariate (BMI) . If I do not add BMI into the USEVAR section, it cannot read the variable and I get the error message: "Unknown variable(s) in an ON statement: BMI"
If I do add my covariate into the USEVAR list, I get another error message: "Variable is uncorrelated with all other variables within class: BMI"
Thank you so much, it worked! Now that I am reading the syntax I was copying from I realise that there was in fact 1 less class in the "MODEL" section than they were testing for - can't believe I missed that.
Nour Azhari posted on Tuesday, April 17, 2018 - 12:29 pm
I am regressing my latent class variable (C) onto several covariates using some code my advisor gave me. I am curious about the meaning of the class specific statements at the bottom of the code. The values are the logits from the classification probabilities from the GMM. but what purpose do they serve in this regression??? He said soemthing about accounting for uncertainty in classification, but I'm just not clear on how they factor into the regression analyses and what they are actually doing to the results? (These are all binary vars, so it's logistic regression.)
C ON MALE BLACK WELFARE POVERTY TWOPAR ART BUILD SCIENCE GAMES READTO NUMBERS EXPECT SPANK DINNER BEDTIME PTO FUNDRS VOLSCH;
Have a look at the V8 UG, page 559 (it's on the web if you don't have the book). The table at the top shows that transition logits are a function of not only "b" parameters but also "a" parameters. See also our Web Note 13 where the relationship between logits and probabilities is explained.