hurdle model
On Thu, 2010-08-19 at 09:52 +0200, Yingjie Zhang wrote:
Hello everyone, Does anyone of you using hurdle model? I am reading a paper which said " Hurdle model removes effect of zero-inflation and over-dispersion in the non-zero observations using a quasi-likelihood", I've checked the help file from hurdle in R, which said differently that"for non-zero obs normally a truncated poisson/NB is used" ... just want to make sure, does it really estimated the parameter by "quasi-likelihood" Thanks, Yingjie Zhang Biostatistician
The authors of that paper might have fitted their hurdle model using a quasi likelihood but that is not, AFAICT, what is used in the hurdle() function in package 'pscl', which maximises a proper log likelihood. But hard to say from what you have provided. G
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