Hi all, I've got an issue with the following. It used to work in the past, but doesn't do so anymore. I want to estimate a panel model for a sub-sample dataset. I am using current cvs on linux. <hansl> open abdata.gdt # Restriction for which panel structure remains smpl YEAR > 1977 --restrict smpl full # Restriction for which panel structure doesn't remain # -> Undated dataset smpl YEAR > 1977 && EMP > 40 --restrict # Redefinition to panel structure is not allowed acc. to gretl setobs unit YEAR --panel-vars <\hans>

This whole thing needs some more investigation. I guess for consistency we should either scrap the --balanced option or reactivate the balancing mode that's now disabled. Whenever I try to think this issue through it makes my head hurt, but I'll see what I can do...

On Tue, 1 Oct 2013, Riccardo (Jack) Lucchetti wrote: >> This whole thing needs some more investigation. I guess for consistency we >> should either scrap the --balanced option or reactivate the balancing mode >> that's now disabled. Whenever I try to think this issue through it makes >> my head hurt, but I'll see what I can do... > > Personal opinion: if a panel structure is in force, --balanced should be > implicit in smpl. Rationale: a panel dataset is a panel dataset. It simply > can't stop being a panel dataset because you are sub-sampling it. If you > really want it to be interpreted differently, then you have setobs for > that. I hear you, but not all users have that expectation. At one time what the --balanced option does was the default, but I changed that (a long time ago now) after hearing from some users that they found the effect surprising, even disconcerting ("I thought I'd got rid of those rows, but there they still are, just with NAs substituted").

FWIW, my first thought was to agree with Jack (the user). However I haven't worked much with panel data so I recognize this may not be the majority view. It certainly seems non-straightforward.

-----Original Message----- From: gretl-users-bounces(a)lists.wfu.edu [mailto:gretl-users-bounces@lists.wfu.edu] On Behalf Of Riccardo (Jack) Lucchetti Sent: Tuesday, October 01, 2013 3:08 PM To: Allin Cottrell Cc: Gretl list Subject: Re: [Gretl-users] issue defining a panel with sub-sample data On Tue, 1 Oct 2013, Allin Cottrell wrote: > On Tue, 1 Oct 2013, Riccardo (Jack) Lucchetti wrote: > >>> This whole thing needs some more investigation. I guess for >>> consistency we should either scrap the --balanced option or >>> reactivate the balancing mode that's now disabled. Whenever I try to >>> think this issue through it makes my head hurt, but I'll see what I can do... >> >> Personal opinion: if a panel structure is in force, --balanced should >> be implicit in smpl. Rationale: a panel dataset is a panel dataset. >> It simply can't stop being a panel dataset because you are >> sub-sampling it. If you really want it to be interpreted differently, >> then you have setobs for that. > > I hear you, but not all users have that expectation. At one time what > the --balanced option does was the default, but I changed that (a long > time ago > now) after hearing from some users that they found the effect > surprising, even disconcerting ("I thought I'd got rid of those rows, > but there they still are, just with NAs substituted"). Hm. I'd like very much to reconsider that. Opinions?