TGARCH variance
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Hi I have estimate the conditional variance of a given financial time series data under the hypothesis that the returns follow a student t distribution with this specification
spec = garchset('P',1,'Q',1,'C',NaN,'Distribution','T','Display','off');
h=par.K + par.ARCH+par.GARCH;
I want this to estimate the Value at Risk. What I wanna know is if the variance estimated with this code is corrected by the degrees of freedom (I have set the degrees of freedom 10).I can't find in any manual how this variance is estimated and if is corrected by the degrees of freedom! Thank you very much.
EDIT [25 May 2012, 13:36 BST - OK] Added code from comments.
T=length(r); WE=1000;
p = 0.01;
VaR = zeros(T,1);
spec = garchset('P',1,'Q',1,'C',NaN,'Distribution','T','Display','off');
for t=WE+1:T
t1 = t-WE; t2 =t-1;
window = r(t1:t2);
[par, errors, LLF, innovations, ht]=garchfit(spec,window);
h=par.K + par.ARCH*window(end)^2+par.GARCH*ht(end)^2;
VaR(t,1)=-sqrt(h)*tinv(p,10);
end
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