[R] Deviance in Zero inflated models

Achim Zeileis Achim.Zeileis at uibk.ac.at
Thu Apr 4 09:17:11 CEST 2013

On Wed, 3 Apr 2013, Lia McKinnon wrote:

> Dear list,
> I am running some zero inflated models and would like to know what the 
> deviance of the models. Unlike running a normal GLM where the deviance 
> is displayed in the summary all that is displayed in a summary of the 
> zero inflated model is the log likelihood.

Zero-inflated models are not associated with a deviance in the GLM sense. 
They are a mixture of two models rather than a single model from an 
exponential family.

Hence, zeroinfl/hurdle in "pscl" reports the log-likelihood but not the 
deviance. Possibly -2 times the likelihood is useful for you - as Ben 
already pointed out.


> I hope this isn't a read the manual question, and if it is I apologize 
> for wasting your time, but if you could still send me a link of where I 
> might find this information I would be very grateful!
> Thank you
> Lia
> 	[[alternative HTML version deleted]]
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

More information about the R-help mailing list