Hi all,

 

Cameron and Trivedi in their 1998 Regression Analysis of Count Data refer to
NB1 and NB2

 

NB1 is the negative binomial model with variance = mu + (alpha * mu^1)
yielding (1+alpha)*mu

 

NB2 sets the power to 2; hence, variance = mu + (alpha*mu^2)

 

I think that NB2 can be requested via

 

negbin2<-glm(hhm~sex+age,family=quasi(var="mu^2",link="log"))

 

Is that right? If so, how I can get NB1? The quasi family appears to be very
limited in variance specification options.

 

Thanks,

Jeff

 

 


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