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dependent variable lagged

Posted: Thu Aug 02, 2012 6:15 am
by startz
A user has reported what looks to me to be a bug here: http://forums.eviews.com/viewtopic.php?f=4&t=6536

I did the the following test.

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create u 100 series x=nrnd ls x c x(-1) ls x(-1) c x
Unlike the OP, I got an F-stat. However, note that I got different R^2, which is wrong unless it's round-off error.
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Re: dependent variable lagged

Posted: Thu Aug 02, 2012 9:25 am
by EViews Gareth
In the first you're regressing X on its future value, in the second you're regressing X on its past value.

Different estimations.


Perhaps you meant an example such as:

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create u 100 series x=nrnd ls x c x(1) ls x(-1) c x
Which also gives different R^2. That's because the sample is different.

Re: dependent variable lagged

Posted: Thu Aug 02, 2012 9:31 am
by startz
In the first you're regressing X on its future value, in the second you're regressing X on its past value.

Different estimations.
Gareth,

I don't think so.Both equation windows show the same sample.

And in a bivariate regression the R^2 should be the same whether you regress y on x or x on y. (The square of the correlation coefficient.)

Perhaps this is an issue of exactly how the R^2 is calculated, since the means of the dependent variables will be slightly different?

Re: dependent variable lagged

Posted: Thu Aug 02, 2012 10:04 am
by EViews Glenn
There is something strange but I'm not sure what it might be. If I had to bet I think it's the fact that the descriptive statistics aren't computing the lagged dependent properly. I'll look into it.