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the cross section dependence (cd) test
Posted: Wed Oct 15, 2008 1:18 pm
by farnaz
how can I go through the cross section dependence (cd) test for panel data?
Re: the cross section dependence (cd) test
Posted: Fri Oct 17, 2008 2:01 pm
by EViews Glenn
how can I go through the cross section dependence (cd) test for panel data?
The question is a bit vague, but I'm assuming that you mean the Pesaran (2004) CD test. There are two variants, an ordered (p) and non-ordered one. I'm only going to be discussing the non-ordered one here, but the extension to the ordered is pretty straightforward. A related test statistic is the original Breusch-Pagan CD statistic.
None of these statistics are particularly difficult to compute in EViews, the only real issue is that EViews 6 does not compute correlations across panel units as an in-built operation. What you
can do is to take the residuals from your panel equation and unstack them in a new workfile page, then compute the correlations amongst the unstacked series.
The following code snippet shows how to do this operation in a couple of steps, and then performs the actual computation of the BP and Pesaran statistics. The statistics and p-values are saved in scalars, but you could put them in tables instead if desired.
I've done a bit of quick validation of the Pesaran results, but haven't had a chance to check the BP results against anything. The usual disclaimers about using at your own risk apply.
The code below assumes that the original data are in a workfile page called panel. When completed, the results will be in a new page called stacked. To change back to the original page, issue a "pageselect panel" command...Note also that this code assumes that you are using EViews 6. You can compute the unbalanced pairwise correlations in EViews 5, but it's a lot more work.
I should point out that the workfile that I am using as an example below is structured using the cross-section ID series ID01 and period ID series ID02.
Code: Select all
' select the original panel page
pageselect panel
' estimate the original equation with fixed effects
equation eq01.ls(cx=f) impor rd frd c
' make the residuals in stacked form
eq01.makeresid presid
' unstack into a new page page
pageunstack(page=unstack) id01 id02 @ presid
' compute the uncentered correlation and number of observations of the unstacked residuals by cross-section
do presid.cov(out=a) ucor obs
' get number of groups
scalar n = @columns(acorr)
' get vech of observations
vector t = @vech(aobs)
' adjust correlation matrix to zero out diagonals
acorr = acorr - @identity(n)
' get the vech of the correlation matrix and the squared vech
vector vcor = @vech(acorr)
vector vcor2 = @epow(vcor, 2)
' compute the scaled Breusch-Pagan LM stat (generalized slightly for unbalanced)
scalar cdlm = @inner(vcor2, t) - n*(n-1)/2
cdlm = cdlm / @sqrt(n * (n-1))
scalar cdlmpval = 2*@cnorm(-@abs(cdlm))
' compute the Pesaran CD test
vector sqrtt = @sqrt(t)
scalar cd= @inner(vcor, sqrtt)
cd = cd * @sqrt(2 / (n * (n-1)))
scalar cdpval = 2*@cnorm(-@abs(cd))
Hope that this answers your question.
Re: the cross section dependence (cd) test
Posted: Sat Oct 18, 2008 4:40 pm
by farnaz
hi
Thank you for your reply.
Actualy I meant the cross section dependence (cd) test from Pesaran (2004). could it be poosible to give me step by step gudance for that in eviews please. I am trying to perform this test through 6 banks and between my defined dependent and on one of my high correlated independent variable.
Thank you in advance
Kindregards
Farnaz
Re: the cross section dependence (cd) test
Posted: Mon Oct 20, 2008 10:25 am
by EViews Glenn
My earlier post shows how to perform both the Breusch-Pagan test and the Pesaran CD test.
Re: the cross section dependence (cd) test
Posted: Sat Jun 30, 2012 5:51 am
by eva
hi,
I've tried to do this test (adapted to my workfile) and it always gives me the same error message when I try to unstack the residuals:
'series sepecified for unstacking does not have valid values for forming series name'
What do I do wrong?
thank you,
Re: the cross section dependence (cd) test
Posted: Sat Jun 30, 2012 1:25 pm
by EViews Gareth
The series you are using for stacking does not contain entries that are valid as series names. The values cannot start with a number, not have spaces in them, and not contain certain special characters.
Re: the cross section dependence (cd) test
Posted: Sun Jul 01, 2012 7:08 am
by eva
hi,
Thank you for your response.
I don't think any of this is the case. I use country names for unstacking.
I have attached the workfile I'm using. id01 = country and id02 = dateid in my case.
thank you in advance
Re: the cross section dependence (cd) test
Posted: Sun Jul 01, 2012 12:31 pm
by EViews Gareth
"New Zealand" has a space in it.
Re: the cross section dependence (cd) test
Posted: Wed Jan 09, 2013 3:19 am
by wolly77
Hi guys,
a simple question. What is the null hypothesis in this test constructed in Eviews? A p-value = 0.35 implies that the cross sections are dependent? Thank you.
Re: the cross section dependence (cd) test
Posted: Wed Jan 09, 2013 12:14 pm
by EViews Glenn
The null is independence.
Re: the cross section dependence (cd) test
Posted: Fri Jan 02, 2015 3:28 pm
by codru
Hello,
I want to test for cross-sectional independence. I am running a multi-equation model using the system object and SURE as an estimator. My panel data is unabalanced. I work with data for several countries, and for each country I have 2 equations and at least 20 annual observations. Is there any add-in for a CD test for system objects? If not what is the best way to proceed?
thank you, c.
Re: the cross section dependence (cd) test
Posted: Wed Jan 21, 2015 3:58 am
by RheaMaria
Hi I've been trying to follow your instructions for a cross section dependence test and the Breusch Pagan test. However when I try to get the number of groups using the code
scalar n = @columns(acorr)
I get the error message saying 'acorr is not defined'. Could you please advise me how to sort this out so I can compute the test statistics?
Also, is the add-in for cross sectional dependence valid to use for panel data?
Thanks
Rhea