Hi there. I am a student / very fresh R user who is currently having some issues running the procedure for a Hausman test in R.
The head for my data sheet named "data" looks like this: Bird Season Gully Grouping Food Habitat.Type 1 83 1 1 1 0.15 2 2 47 1 1 1 0.09 1 3 47 1 1 1 1.34 3 4 47 1 1 1 0.09 1 5 51 1 1 3 0.15 2 6 51 1 1 3 0.15 2 The code to run the test looks like this: library(plm) result=read.csv("H:/data",header=T,sep=",",stringsAsFactors=F) wi=plm(Habitat.Type~Season+Gully+Grouping+Food, data = result, index =c("Bird"),model="within") re=plm(Habitat.Type~Season+Gully+Grouping+Food, data = result, index =c("Bird"),model="random") phtest(wi, re) The reasoning behind this format is that Habitat.Type is the dependant variable. Season, Gully, Grouping and Food are the independant variables. Bird (ID) is the index as it is the random effect. The error message I am getting is this: duplicate couples (time-id) Error in pdim.default(index[[1]], index[[2]]) >From what I have been able to figure out this may be because I have multiple identical observations. The problem is that I do not want to remove these multiple identical observations, as that is a large part of my data. My question to you - am I doing anything wrong? Is there a work around for the duplicate error that I am getting without removing identical observations? Thanks so much for your help. -- View this message in context: http://r.789695.n4.nabble.com/Hausman-Test-trouble-plm-tp4709990.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.