Beta-coefficients for ZINB model

Dear users,

Does anyone have any idea how to generate standardised beta coefficients
for a ZINB model in R to compare which explanatory variables are having the
greatest impact on the dependent variable?

You might like to look at Ulrike Gr?mping's work 
on relative importance in regression. Not sure 
how directly this translates into the non-linear case though.

J Stat Soft October 2006 vol 17 number 1

Thanks,
Jeremy

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Michael Dewey
info at aghmed.fsnet.co.uk
http://www.aghmed.fsnet.co.uk/home.html

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