[R] negative binomial lmer

Ben Bolker bolker at ufl.edu
Fri Jul 28 16:52:27 CEST 2006

Tracy Feldman <tracysfeldman <at> yahoo.com> writes:

> To whom it may concern:
>   I have a question about how to appropriately conduct an lmer analysis for
negative binomially distributed
> data.  I am using R 2.2.1 on a windows machine. 
>   I am trying to conduct an analysis using lmer (for non-normally distributed
data and both random and fixed
> effects) for negative binomially distributed data.  To do this, I have been
using maximum likelihood,
> comparing the full model to reduced models (containing all but one effect, for
all effects).  However, for
> negative binomially distributed data, I need to estimate the parameter theta.
 I have been doing this by
> using a negative binomial glm of the same model (except that all the effects
are fixed), and estimating mu
> as the fitted model like so:

 I haven't tried it, but you could also consider using
a Poisson-lognormal (rather than neg binomial, which is Poisson-gamma)
distribution, which might make this all work rather well
in lmer:


    Ben Bolker

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