Orthogonality C test - matrix problem

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Ties
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Joined: Mon Mar 09, 2015 9:55 am

Orthogonality C test - matrix problem

Postby Ties » Mon Mar 09, 2015 10:19 am

Hi all,

I have to test for endogeinity and when performing the orthogonality c test using TSLS on my instruments I get an error: "Weighting matrix is of wrong size". What does this mean and how can I solve this?

My formula is:
stn = c + hicpp-2 + ygapp + r + r*(hicpp-2) + r*(ygapp) + ar(1)
and white robust standard errors

Instruments are pcr (private consumption), nxr (net exports), itr (gross investment), compr (comodity prices), urx (unemployment rate).


Kind regards,
Ties
Attachments
taylor rule worksheet.wf1
(46.37 KiB) Downloaded 261 times

EViews Gareth
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Re: Orthogonality C test - matrix problem

Postby EViews Gareth » Mon Mar 09, 2015 10:26 am

To which equation object are you referring?

Ties
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Joined: Mon Mar 09, 2015 9:55 am

Re: Orthogonality C test - matrix problem

Postby Ties » Mon Mar 09, 2015 10:39 am

taylor_white_ar is the equation I am using

EViews Gareth
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Re: Orthogonality C test - matrix problem

Postby EViews Gareth » Mon Mar 09, 2015 11:05 am

We don't support equations with AR terms with automatically added instruments for the ar terms for that test. The error message should be more informative, sorry.

Ties
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Joined: Mon Mar 09, 2015 9:55 am

Re: Orthogonality C test - matrix problem

Postby Ties » Mon Mar 09, 2015 11:10 am

So I should remove the AR(1) for the equation? But still my model needs to be corrected for serial correlation and heteroskedasticity. How do I solve that?

EViews Gareth
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Re: Orthogonality C test - matrix problem

Postby EViews Gareth » Mon Mar 09, 2015 11:27 am

You can keep the AR term in, as long as you decheck the box that adds lagged values of regressors as instruments. But note if you do that, you'll probably need to add more instruments yourself so that the model is identified.

Ties
Posts: 9
Joined: Mon Mar 09, 2015 9:55 am

Re: Orthogonality C test - matrix problem

Postby Ties » Mon Mar 09, 2015 1:27 pm

I have dechecked the box for including lagged regressors for linear equations with ARMA and added one more instrument (therefore it does not give the error "not enough instruments" anymore). However now I get an error stating: "singular matrix". How do I solve this?

-edit: could I be suffering from a dummy variable trap?

The new workfile is added to this comment (hence that I checked the box to be able to save the equation).
Attachments
taylor rule worksheet.wf1
(48.09 KiB) Downloaded 272 times
Last edited by Ties on Mon Mar 09, 2015 1:33 pm, edited 1 time in total.

EViews Gareth
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Re: Orthogonality C test - matrix problem

Postby EViews Gareth » Mon Mar 09, 2015 1:29 pm

Probably need even more instruments

Ties
Posts: 9
Joined: Mon Mar 09, 2015 9:55 am

Re: Orthogonality C test - matrix problem

Postby Ties » Mon Mar 09, 2015 1:41 pm

Need those instruments be in percentages? (The data for estimators are in percentages)


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