Hi, I am solving a model where I simplified the equations looking for the MSV version. The reason is that I wanted to avoid singularity problems (BK type) and because I want to solve several Ramsey Planner Problems using the private eq. as input, and thus, I would prefer the smallest possible system to reduce dimensionality curse issues (and again, Blanchard-Kahn issues in the planner model).
The MSV model does not have variables that I care about. Is there a fast way to obtain the IRF for this (substituted variables) from the remaining ones?
Say for example, that I substituted the output, to get rid of an equation. My model still has its components (A , H, K). Can I create the IRF for Y, operating the IRFs for (A,H,K) like this?:
y2 = simult_(M_,options_,initial_condition_states,oo_.dr,shock_matrix,1);
y_IRF = y2(:,M_.maximum_lag+1:end)-repmat(oo_.dr.ys,1,options_.irf); %deviation from steady state
Ktemp = y_IRF(strmatch('K',M_.endo_names,'exact'),:); Htemp = y_IRF(strmatch('H',M_.endo_names,'exact'),:); Atemp = y_IRF(strmatch('A',M_.endo_names,'exact'),:);
And then use:
Yirf = exp(Atemp)*Htemp^(1-alphha)*Ktemp^(alphha);
as in the longer (more equations) version of the same model?