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var sign restriction

Posted: Fri Mar 22, 2013 4:52 am
by hichbenn
I'm looking for a code where I can impose sign parameters restricitons on VAR models.

I found this way to do it for a simple regression: "To impose a positive sign on coefficient of y(t-1) write y(t)=(exp(a)))*y(t-1)+...You then need to use a non-linear regression program to estimate a. For negative of course you would just write (-exp(a))*y(t-1)"

Would you please help me to find a code to do it using a VAR model.

Re: var sign restriction

Posted: Fri Mar 22, 2013 11:25 am
by TomDoan
Why would you want to do that? VAR coefficients generally have signs that switch from lag to lag due to the high correlation of adjacent lags.