This is a nontrivial problem. This comes up often on the Statalist (-qreg- is for cross-section quantile regression): " You want to fit a plane through the origin using the L-1 norm. This is not as easy as with L-2 norm (LS), as it is more than a matter of dropping a constant predictor yet otherwise using the same criterion of fit. You are placing another constraint on a problem that already does not have a closed-form solution, and it does not surprise me that -qreg- does not support this. " (N.J. Cox) http://www.stata.com/statalist/archive/2007-10/msg00809.html
You will probably have to program this by hand. Note also the degeneracy conditions in Koenker (2003, pg. 36--). I am not sure how this extends to panel data though. References: @book{koenker2005qre, title={{Quantile Regression; Econometric Society Monographs}}, author={Koenker, R.}, year={2005}, publisher={Cambridge University Press} } T On Sun, Apr 26, 2009 at 8:24 AM, Helen Chen <96258...@nccu.edu.tw> wrote: > > Hi, > > I am trying to estimate a quantile regression using panel data. I am trying > to use the model that is described in Dr. Koenker's article. So I use the > code the that is posted in the following link: > > http://www.econ.uiuc.edu/~roger/research/panel/rq.fit.panel.R > > How to estimate the panel data quantile regression if the regression > contains no constant term? I tried to change the code of rq.fit.panel by > delect "X=cbind(1,x)" and would like to know is that correct ? > > > Thanks > I really would appreciate some suggestions. > Best > Helen Chen > -- > View this message in context: > http://www.nabble.com/Question-of-%22Quantile-Regression-for-Longitudinal-Data%22-tp23239896p23239896.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help@r-project.org mailing list > 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. > -- To every ω-consistent recursive class κ of formulae there correspond recursive class signs r, such that neither v Gen r nor Neg(v Gen r) belongs to Flg(κ) (where v is the free variable of r). ______________________________________________ R-help@r-project.org mailing list 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.