Hi, I have two questions. First, I'd like to compare a ZINB model to a negativ binomial model with the Vuong test, but I can't find how to performe it from the zicount package. Does a programm exist to do it ? Second, I'd like to know in which cases we have to use a double hurdle model instead of a zero inflated model. Many thanks, St??phanie Payet REES France R??seau d'Evaluation en Economie de la Sant?? 28, rue d'Assas 75006 PARIS T??l. +33 (0)1 44 39 16 90 Fax +33 (0)1 44 39 16 92 M??l. reesfrance at wanadoo.fr Site Internet : rees-france.com
Hi St??phanie, The Vuong test can be done in Stata (stata.com/support/faqs/stat/vuong.html), but I am also looking for its code in R. In addition to "zicounts", Dr. Simon Jackman (pscl.stanford.edu) has provided the code for fitting the zero-inflated (pscl.stanford.edu/zeroinfl.r) and hurdle (pscl.stanford.edu/hurdle.r) count models. Reza On 5/17/05, St??phanie PAYET <spayet.reesfrance at wanadoo.fr> wrote:> Hi, > > I have two questions. First, I'd like to compare a ZINB model to a negativ > binomial model with the Vuong test, but I can't find how to performe it from > the zicount package. Does a programm exist to do it ? > Second, I'd like to know in which cases we have to use a double hurdle model > instead of a zero inflated model. > > Many thanks, > > St??phanie Payet > > REES France > R??seau d'Evaluation en Economie de la Sant?? > 28, rue d'Assas > 75006 PARIS > T??l. +33 (0)1 44 39 16 90 > Fax +33 (0)1 44 39 16 92 > M??l. reesfrance at wanadoo.fr > Site Internet : rees-france.com > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! R-project.org/posting-guide.html >