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"positive or non-negative argument" with panel gls estimate
Posted: Sun Sep 25, 2011 7:55 pm
by cao10008
when I run panel gls( cross-section effect , cross-section weight),
dependt var is toa, independent is mktpwr, crossid is stoc
the message diplayed is "positive or non-negative argument to function expected in computation of group weight(variance)"
I don't know how to deal with it correctly. The wf1 file is attached, help pls!
Re: "positive or non-negative argument" with panel gls estim
Posted: Mon Sep 26, 2011 10:15 am
by EViews Glenn
You can see what's going on if you run your model without the cross-section weights and compute residuals, you'll see that for cross-section 600603, you have but a single observation. With the fixed effects added for this cross-section, the residual is identically equal to zero so that we are unable to compute cross-section weights.
Re: "positive or non-negative argument" with panel gls estim
Posted: Tue Sep 27, 2011 3:42 am
by cao10008
You can see what's going on if you run your model without the cross-section weights and compute residuals, you'll see that for cross-section 600603, you have but a single observation. With the fixed effects added for this cross-section, the residual is identically equal to zero so that we are unable to compute cross-section weights.
Thanks, I have checked my data, it is really as what you discribe. And when I exclude this cross-section , the message diappears.
So when that message pops up, does it suggest that observations for some cross- section be too few, and I should check it?
Under other circumstances, will this message pop up?
Re: "positive or non-negative argument" with panel gls estim
Posted: Tue Sep 27, 2011 9:06 am
by EViews Glenn
In this context it means that there is at least one cross-section with zero variances for the residuals. There are a variety of reasons why this might occur, one of which was present in this case...
Re: "positive or non-negative argument" with panel gls estim
Posted: Tue Sep 27, 2011 8:18 pm
by cao10008
In this context it means that there is at least one cross-section with zero variances for the residuals. There are a variety of reasons why this might occur, one of which was present in this case...
Thanks a lot, Glenn. Your explaination is very helpful.
I wish Eviews could publish an error message book for us in the future, or just as a part of appendix of "command and programm".