Hi, I know this is probably a stupid question... But I don't seem to find the answer. I'm fitting a GLM with a Poisson family, using MASS, and then tried to get a look at the predictions, however the offset does seem to be taken into consideration: model_glm=glm(cases~rhs(data$year,2003)+lhs(data$year,2003), offset=(log(population)), data=data, subset=28:36, family=poisson()) predict (model_glm, type="response") I get cases not rates... I've tried also model_glm=glm(cases~rhs(data$year,2003)+lhs(data$year,2003)+ offset(log(population)), data=data, subset=28:36, family=poisson()) with the same results. However when I predict from GAM, using mgcv, the predictions consider the offset (I get rates). I'm missing something? I would appreciate any comment, thanks Sandra -- View this message in context: http://r.789695.n4.nabble.com/predict-GLM-with-offset-MASS-tp4556308p4556308.html Sent from the R help mailing list archive at Nabble.com.