I am looking into which package to use in R to handle a zero-inflated Poisson model for repeated measures (growth curve analysis through multiple level modeling).

>From what I can tell, the lme4 package can handle the Poisson model and repeated measures but can't handle the zero-inflated Poisson model.  The pscl package can handle the zero-inflate Poisson model but can't handle repeated measures.  And that leaves the glmmADMB package as being the only package in R that can handle a zero-inflated Poisson model for repeated measure.

Is this correct?  Or is there a package in R other than the glmmADMB package that I should be considering?

And if the glmmADMB package is the only package for this purpose, can the glmmADMB handle a 3-level multi-level model (hierarchical linear model)?

The model that I am working on has TIME at level 1, FIRMS at level 2, and LOCATIONS (metropolitan statistical areas) at level 3.  The dependent variable at level 1 is a count variable (number of credit sources used by a firm) which has an over dispersion of zeros at various points in time.  Thus, the reason why I am having to use a zero-inflated Poisson model (or I could use a hurdle model).

Thanks for your help.

- JM

	[[alternative HTML version deleted]]

