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Coherence and phase

Posted: Tue Jul 07, 2015 1:01 pm
by Alberto
Hi Tom,
I am trying to implement an exercise based on spectral analysis methods in the spirit of Sargent 1987 (Macroec. Theory, 2nd ed., sect 11. Alternative definitions of the business cycle) looking at spectrum, coherence and phase of various real GDP annual growth rate measures. I attach a sample programme looking at these measures for US, UK and Japan from 1961q1 to 2014q4 using the @spectrum and @crosspec procedures.
I have three main questions:
1) how can I save or display separately coherence and phase lead from the @crossspec procedure (there is no option to save them as for spectrum in the @spectrum, right?)?
2) how can I change the horizontal scale for the spectrum, say to have it in fractions of pi?
2) I am not sure what the best options such as ordinates, window, weights etc. are as they seem to differ across examples from Hamilton, Brock and Davis etc.: would you have any practical guidance?
thanks a lot
Alberto

Re: Coherence and phase

Posted: Mon Jul 13, 2015 9:38 pm
by TomDoan
Alberto wrote:Hi Tom,
I am trying to implement an exercise based on spectral analysis methods in the spirit of Sargent 1987 (Macroec. Theory, 2nd ed., sect 11. Alternative definitions of the business cycle) looking at spectrum, coherence and phase of various real GDP annual growth rate measures. I attach a sample programme looking at these measures for US, UK and Japan from 1961q1 to 2014q4 using the @spectrum and @crosspec procedures.
I have three main questions:
1) how can I save or display separately coherence and phase lead from the @crossspec procedure (there is no option to save them as for spectrum in the @spectrum, right?)?
I added options for that to the procedure. See

https://estima.com/forum/viewtopic.php?f=7&t=2404
Alberto wrote: 2) how can I change the horizontal scale for the spectrum, say to have it in fractions of pi?
That's what it was already doing.
Alberto wrote: 3) I am not sure what the best options such as ordinates, window, weights etc. are as they seem to differ across examples from Hamilton, Brock and Davis etc.: would you have any practical guidance?
A flat window with a width somewhere around the square root of the number of ordinates generally works OK unless the spectrum has very sharp features.

Re: Coherence and phase

Posted: Wed Jul 15, 2015 11:25 am
by Alberto
Great, thanks a lot for your feedback.
Best regards
Alberto