dynare/matlab/DsgeVarLikelihood.m

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7.0 KiB
Matlab
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function [fval,cost_flag,ys,trend_coeff,info,PHI,SIGMAu,iXX] = DsgeVarLikelihood(xparam1,gend)
% stephane.adjemian@ens.fr
global bayestopt_ estim_params_ M_ options_ xparam1_test
global xparam_
nvx = estim_params_.nvx;
nvn = estim_params_.nvn;
ncx = estim_params_.ncx;
ncn = estim_params_.ncn;
np = estim_params_.np;
nx = nvx+nvn+ncx+ncn+np;
ns = nvx+nvn+ncx+ncn;
info = [ ];
mYY = evalin('base', 'mYY');
mYX = evalin('base', 'mYX');
mXY = evalin('base', 'mXY');
mXX = evalin('base', 'mXX');
fval = [];
cost_flag = [];
ys = [];
trend_coeff = [];
xparam1_test = xparam1;
cost_flag = 1;
nobs = size(options_.varobs,1);
if options_.mode_compute ~= 1 & any(xparam1 < bayestopt_.lb)
k = find(xparam1 < bayestopt_.lb);
fval = bayestopt_.penalty*min(1e3,exp(sum(bayestopt_.lb(k)-xparam1(k))));
cost_flag = 0;
return;
end
if options_.mode_compute ~= 1 & any(xparam1 > bayestopt_.ub)
k = find(xparam1 > bayestopt_.ub);
fval = bayestopt_.penalty*min(1e3,exp(sum(xparam1(k)-bayestopt_.ub(k))));
cost_flag = 0;
return;
end
Q = M_.Sigma_e;
for i=1:estim_params_.nvx
k = estim_params_.var_exo(i,1);
Q(k,k) = xparam1(i)*xparam1(i);
end
offset = estim_params_.nvx;
if estim_params_.nvn
H = zeros(nobs,nobs);
for i=1:estim_params_.nvn
k = estim_params_.var_endo(i,1);
H(k,k) = xparam1(i+offset)*xparam1(i+offset);
end
offset = offset+estim_params_.nvn;
end
if estim_params_.ncx
for i=1:estim_params_.ncx
k1 =estim_params_.corrx(i,1);
k2 =estim_params_.corrx(i,2);
Q(k1,k2) = xparam1(i+offset)*sqrt(Q(k1,k1)*Q(k2,k2));
Q(k2,k1) = Q(k1,k2);
end
[CholQ,testQ] = chol(Q);
if testQ%% The variance-covariance matrix of the structural innovations is not definite positive.
%% We have to compute the eigenvalues of this matrix in order to build the penalty.
a = eig(Q);
k = a<0;
if k > 0
fval = bayestopt_.penalty*min(1e3,exp(sum(-a(k))));
cost_flag = 0;
return
end
end
offset = offset+estim_params_.ncx;
end
if estim_params_.nvn & estim_params_.ncn
for i=1:estim_params_.ncn
k1 = options_.lgyidx2varobs(estim_params_.corrn(i,1));
k2 = options_.lgyidx2varobs(estim_params_.corrn(i,2));
H(k1,k2) = xparam1(i+offset)*sqrt(H(k1,k1)*H(k2,k2));
H(k2,k1) = H(k1,k2);
end
[CholH,testH] = chol(H);
if testH
a = eig(H);
k = a<0;
if k > 0
fval = bayestopt_.penalty*min(1e3,exp(sum(-a(k))));
cost_flag = 0;
return
end
end
offset = offset+estim_params_.ncn;
end
M_.params(estim_params_.param_vals(:,1)) = xparam1(offset+1:end);
M_.Sigma_e = Q;
%% Weight of the dsge prior:
dsge_prior_weight = M_.params(strmatch('dsge_prior_weight',M_.param_names));
%------------------------------------------------------------------------------
% 2. call model setup & reduction program
%------------------------------------------------------------------------------
[T,R,SteadyState,info] = dynare_resolve(bayestopt_.restrict_var_list,...
bayestopt_.restrict_columns,...
bayestopt_.restrict_aux);
if info(1) == 1 | info(1) == 2 | info(1) == 5
fval = bayestopt_.penalty;
cost_flag = 0;
return
elseif info(1) == 3 | info(1) == 4 | info(1) == 20
fval = bayestopt_.penalty*min(1e3,exp(info(2)));
cost_flag = 0;
return
end
if options_.loglinear == 1
constant = log(SteadyState(bayestopt_.mfys));
else
constant = SteadyState(bayestopt_.mfys);
end
if bayestopt_.with_trend == 1
trend_coeff = zeros(nobs,1);
for i=1:nobs
trend_coeff(i) = evalin('base',bayestopt_.trend_coeff{i});
end
trend = constant*ones(1,gend)+trend_coeff*(1:gend);
else
trend = constant*ones(1,gend);
end
%------------------------------------------------------------------------------
% 3. theorretical moments (second order)
%------------------------------------------------------------------------------
tmp = lyapunov_symm(T,R*Q*R');% I compute the variance-covariance matrix
% of the restricted state vector.
bayestopt_.mf = bayestopt_.mf1;
mf = bayestopt_.mf1;
NumberOfObservedVariables = size(options_.varobs,1);
NumberOfLags = options_.varlag;
k = NumberOfObservedVariables*NumberOfLags ;
TheoreticalAutoCovarianceOfTheObservedVariables = ...
zeros(NumberOfObservedVariables,NumberOfObservedVariables,NumberOfLags+1);
TheoreticalAutoCovarianceOfTheObservedVariables(:,:,1) = tmp(mf,mf);
for lag = 1:NumberOfLags
tmp = T*tmp;
TheoreticalAutoCovarianceOfTheObservedVariables(:,:,lag+1) = tmp(mf,mf);
end
GYX = zeros(NumberOfObservedVariables,k);
for i=1:NumberOfLags
GYX(:,(i-1)*NumberOfObservedVariables+1:i*NumberOfObservedVariables) = ...
TheoreticalAutoCovarianceOfTheObservedVariables(:,:,i+1);
end
GXX = kron(eye(NumberOfLags), ...
TheoreticalAutoCovarianceOfTheObservedVariables(:,:,1));
for i = 1:NumberOfLags-1
tmp1 = diag(ones(NumberOfLags-i,1),i);
tmp2 = diag(ones(NumberOfLags-i,1),-i);
GXX = GXX + kron(tmp1,TheoreticalAutoCovarianceOfTheObservedVariables(:,:,i+1));
GXX = GXX + kron(tmp2,TheoreticalAutoCovarianceOfTheObservedVariables(:,:,i+1)');
end
GYY = TheoreticalAutoCovarianceOfTheObservedVariables(:,:,1);
assignin('base','GYY',GYY);
assignin('base','GXX',GXX);
assignin('base','GYX',GYX);
if ~isinf(dsge_prior_weight)
SIGMAu = dsge_prior_weight*gend*TheoreticalAutoCovarianceOfTheObservedVariables(:,:,1) + mYY ;
tmp1 = dsge_prior_weight*gend*GYX + mYX;
tmp2 = inv(dsge_prior_weight*gend*GXX+mXX);
SIGMAu = SIGMAu - tmp1*tmp2*tmp1';
SIGMAu = SIGMAu / (gend*(dsge_prior_weight+1));
PHI = tmp2*tmp1';
prodlng1 = sum(gammaln(.5*((1+dsge_prior_weight)*gend- ...
NumberOfObservedVariables*NumberOfLags ...
+1-(1:NumberOfObservedVariables)')));
prodlng2 = sum(gammaln(.5*(dsge_prior_weight*gend- ...
NumberOfObservedVariables*NumberOfLags ...
+1-(1:NumberOfObservedVariables)')));
lik = .5*NumberOfObservedVariables*log(det(dsge_prior_weight*gend*GXX+mXX)) ...
+ .5*((dsge_prior_weight+1)*gend-k)*log(det((dsge_prior_weight+1)*gend*SIGMAu)) ...
- .5*NumberOfObservedVariables*log(det(dsge_prior_weight*gend*GXX)) ...
- .5*(dsge_prior_weight*gend-k)*log(det(dsge_prior_weight*gend*(GYY-GYX*inv(GXX)*GYX'))) ...
+ .5*NumberOfObservedVariables*gend*log(2*pi) ...
- .5*log(2)*NumberOfObservedVariables*((dsge_prior_weight+1)*gend-k) ...
+ .5*log(2)*NumberOfObservedVariables*(dsge_prior_weight*gend-k) ...
- prodlng1 + prodlng2;
else % cod<6F> par SM (s<>rement pas exact... Que font ici les moments empiriques ?).
tmp1 = GYX;
tmp2 = inv(GXX);
PHI = tmp2*tmp1';
SIGMAu = GYY - tmp1*tmp2*tmp1;
% <20> finir de corriger...
lik = -.5*sum(diag(inv(tmp2)*(mYY-2*tmp1'*mYX'+tmp1'*mXX*tmp1))) ...
-(gend/2)*log(det(tmp2));
end
lnprior = priordens(xparam1,bayestopt_.pshape,bayestopt_.p1,bayestopt_.p2,bayestopt_.p3,bayestopt_.p4);
fval = (lik-lnprior);
iXX = tmp2;