multiplicative dummy involving squared residuals and varian

Discussions of ARCH, GARCH, and related models
sulong
Posts: 13
Joined: Sun Mar 20, 2011 1:59 am

multiplicative dummy involving squared residuals and varian

Unread post by sulong »

hi Tom,

is it possible to model the following variance equation using the GARCH instruction?
How can i do that?


thanks
sulong.
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TomDoan
Posts: 7814
Joined: Wed Nov 01, 2006 4:36 pm

Re: multiplicative dummy involving squared residuals and var

Unread post by TomDoan »

No. You would have to do that with MAXIMIZE. Set it up with something like:

Code: Select all

nonlin(parmset=garchparms) g0 g1 g2 g3 gd
frml hf = (1+gd)*(g0 + g1*h{1} + g2*u{1}^2 + %if(u{1}<0.0,g3*u{1}^2,0.0))
frml logl = (h(t)=hf(t)),(u(t)=resid(t)),-.5*(log(h)+u^2/h)
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