[R] To create a Panel and run a Pooled OLS

[Spencer Graves]

I just see a difference between what I wrote and what I use.  Have you 
tried the following:

	OLS <- lm(y~x1+x2, data=Panel)

spencer graves
###################
If yes, could you replicate the error with a small data set that you
send with your help request?  It can make it easier for others to
diagnose.

Hope this helps. spencer graves

langensk at fas.harvard.edu wrote:
 >
 > Dear all,
 >
 > I have tried to merge two cross sections (crossA and crossB) as 
follows, both
 > crossA and crossB include the same variables, e.g., ID,y,x1,x2:
 >
 > Panel <- merge(crossA,crossB,by="ID")
 >
 > I have, thereafter, tried to run the following pooled OLS:
 >
 > OLS <- lm(Panel$y~Panel$x1+Panel$x2)
 >
 > and have received the following error message "Error in 
model.frame(formula,
 > rownames, variables, varnames, extras, extranames,  : invalid 
variable type"
 >
 > I would be very grateful for help. At the moment, I believe that I 
have tried
 > everything.
 >
 > Thanks in advance,
 > Sophie
 >
 > ______________________________________________
 > R-help at stat.math.ethz.ch mailing list
 > https://www.stat.math.ethz.ch/mailman/listinfo/r-help