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Identity equation with "dependent" variable on right side
Posted: Tue Oct 28, 2014 7:30 am
by leah
Is there a way in eviews to solve for an unknown variable in an identity when the unknown variable is impossible to isolate on one side of the equation? This is the equation if it helps:
beta, gamma, phi, and tau are all known series. alpha is unknown -
gamma = ((1-exp(-phi-alpha))*alpha*(gamma(-1)+tau(-1)))/(beta+alpha) + (exp(-phi-alpha))*gamma
Re: Identity equation with "dependent" variable on right sid
Posted: Tue Oct 28, 2014 7:52 am
by EViews Gareth
Not really. You could use the optimize function to get darn close.
Re: Identity equation with "dependent" variable on right sid
Posted: Tue Oct 28, 2014 9:41 am
by leah
Okay, sortof fumbling around in the dark. Is this on the right track? When I run it I get an error saying that the "objective function evaluates to NA for one or more observations".
wfcreate a 2000 2013
fetch(d=na) gdp gdph jfnsco jf
subroutine f(series alpha, series phi, series gamma, series tau, series beta)
gamma = ((1-exp(-phi-alpha))*alpha*(gamma(-1)+tau(-1)))/(beta+alpha)+(exp(-phi-alpha))*gamma
endsub
series out
optimize f(out, gdp, gdph, jfnsco, jf)
Re: Identity equation with "dependent" variable on right sid
Posted: Tue Oct 28, 2014 9:49 am
by EViews Gareth
You'll have to set starting values for alpha.