Zero inflated variables in a GMM PreviousNext
Mplus Discussion > Growth Modeling of Longitudinal Data >
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 Robert Long posted on Friday, October 18, 2013 - 10:25 am
I am using a zero inflated poisson growth mixture model. However, the range of counts is quite high: 0-224 and I get the warning

WARNING: COUNT VARIABLE HAS LARGE VALUES.
IT MAY BE MORE APPROPRIATE TO TREAT SUCH VARIABLES AS CONTINUOUS.

So my question is: what other way can I handle the zero-inflation, while treating the variables as continuous ?
 Linda K. Muthen posted on Friday, October 18, 2013 - 5:00 pm
You could consider the CENSORED option, two-part modeling as shown in Example 6.16, or the method described in the following link on the website:

GLM with log link and Poisson regression for continuous variables

You might also want to get rid of the high values if they are outliers.
 Robert Long posted on Sunday, October 20, 2013 - 12:47 pm
Dear Linda

Thank you for the response. I am now trying to implement a two-part model. Using example 6.16, could you tell me why the mean of the intercept growth factor for the binary part is fixed at zero, and whether this can be relaxed and if so, how ? Also, could you explain what the "Thresholds" part of the model results means with the four values of -0.541

Thanks
 Linda K. Muthen posted on Sunday, October 20, 2013 - 1:35 pm
Please send the output and your license number to support@statmodel.com.
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