Hello, I have a problem with Hausman test. I am performing my analysis with these commands:
> library(plm) > data<-read.csv2("paolo.csv",header=TRUE) > data< pdata.frame(data,index=c("FIRM","YEAR"),drop.index=TRUE,row.names=TRUE) > RECEIV~LSIZE+LAGE+LAGE2+CFLOW+STLEV+FCOST+PGROWTH+NGROWTH+TURN+GPROF+GPROF2 > grun.fe<-plm(RECEIV~LSIZE+LAGE+LAGE2+CFLOW+STLEV+FCOST+PGROWTH+NGROWTH+TURN+GPROF+GPROF2,data=data,model="within") > grun.re <-plm(RECEIV~LSIZE+LAGE+LAGE2+CFLOW+STLEV+FCOST+PGROWTH+NGROWTH+TURN+GPROF+GPROF2,data=data,model="random") > gw<-plm(RECEIV~LSIZE+LAGE+LAGE2+CFLOW+STLEV+FCOST+PGROWTH+NGROWTH+TURN+GPROF+GPROF2,data=data,model="within") > gr<-plm(RECEIV~LSIZE+LAGE+LAGE2+CFLOW+STLEV+FCOST+PGROWTH+NGROWTH+TURN+GPROF+GPROF2,data=data,model="random") > phtest(gw,gr) I got this answer: Error in solve.default(dvcov) : how can I solve this problem? Thank you [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.