A friend of mine sent me below so I am posting below. If it is not enough information, please just let me know and I will tell him. Thanks. -----Original Message----- Sent: Friday, April 13, 2007 3:58 PM To: Leeds, Mark (IED) Subject: R question I am using the "predict" function after I have done a simultaneous estimation of a system using "systemfit". fitsur is the output of systemfit and "system" is my system of equations, "SUR" is the Seemingly Unrelated Regrssions method of estimation. fitsur<-systemfit("SUR",system) I am supposed to be able to use the estimated coefficients for out-of-sample prediction using a different data set than the one originally used for estimation. That is my XSf data frame. Unfortunately whether I include that option(XSf) as in p or not as in q I get the same result from predict in this case. I have confirmed that "predict" works properly for the output of "lm" p<-predict.systemfit(fitsur,XSf) q<-predict.systemfit(fitsur) -------------------------------------------------------- This is not an offer (or solicitation of an offer) to buy/se...{{dropped}}