I've got a question concerning a negbin regression: suppose that you have the following commands
require(MASS) attach(cars) mod.NB<-glm.nb(dist~speed) summary(mod.NB) detach(cars)
(note that cars is a dataset which is available in R) and don't care if this model makes sense. What I'd like to know is, how can I interpret the variable theta (at the bottom of the summary). Is this the shape parameter of the negbin distribution and is it possible to interpret it as a measure of skewness? I appreciate every thought!