st: question on zero inflated regression

[rachel grant <rachelannegrant@gmail.com>]

Hi I am new to the list and pretty clueless.
I am trying to use Zero inflated models, my data are counts of
ampibians arriving at a breeding site per night. Most nights none
arrive or one,  but some nights many arrive hence the data are
overdispersed and have excess zeroes. I am using zero inflated
negative binomial regression. What I am confused about is I have to
specify the inflation variable (ie the one that is generating the
excess zeroes). I have 7 predictor variable and have no clue which is
responsible for generating the zeroes, so what to put into the model
as the inflation variable? Thanks for reading this

--
regards, Rachel

Rachel Grant
Dept. Life Sciences
Open University
UK




--
regards, Rachel

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