dynare/matlab/DsgeSmoother.m

302 lines
12 KiB
Matlab

function [alphahat,etahat,epsilonhat,ahat,SteadyState,trend_coeff,aK,T,R,P,PK,decomp,trend_addition,state_uncertainty,M_,oo_,options_,bayestopt_] = DsgeSmoother(xparam1,gend,Y,data_index,missing_value,M_,oo_,options_,bayestopt_,estim_params_)
% Estimation of the smoothed variables and innovations.
%
% INPUTS
% o xparam1 [double] (p*1) vector of (estimated) parameters.
% o gend [integer] scalar specifying the number of observations ==> varargin{1}.
% o data [double] (n*T) matrix of data.
% o data_index [cell] 1*smpl cell of column vectors of indices.
% o missing_value 1 if missing values, 0 otherwise
% o M_ [structure] decribing the model
% o oo_ [structure] storing the results
% o options_ [structure] describing the options
% o bayestopt_ [structure] describing the priors
% o estim_params_ [structure] characterizing parameters to be estimated
%
% OUTPUTS
% o alphahat [double] (m*T) matrix, smoothed endogenous variables (a_{t|T}) (decision-rule order)
% o etahat [double] (r*T) matrix, smoothed structural shocks (r>=n is the number of shocks).
% o epsilonhat [double] (n*T) matrix, smoothed measurement errors.
% o ahat [double] (m*T) matrix, updated (endogenous) variables (a_{t|t}) (decision-rule order)
% o SteadyState [double] (m*1) vector specifying the steady state level of each endogenous variable (declaration order)
% o trend_coeff [double] (n*1) vector, parameters specifying the slope of the trend associated to each observed variable.
% o aK [double] (K,n,T+K) array, k (k=1,...,K) steps ahead
% filtered (endogenous) variables (decision-rule order)
% o T and R [double] Matrices defining the state equation (T is the (m*m) transition matrix).
% o P: (m*m*(T+1)) 3D array of one-step ahead forecast error variance
% matrices (decision-rule order)
% o PK: (K*m*m*(T+K)) 4D array of k-step ahead forecast error variance
% matrices (meaningless for periods 1:d) (decision-rule order)
% o decomp (K*m*r*(T+K)) 4D array of shock decomposition of k-step ahead
% filtered variables (decision-rule order)
% o trend_addition [double] (n*T) pure trend component; stored in options_.varobs order
% o state_uncertainty [double] (K,K,T) array, storing the uncertainty
% about the smoothed state (decision-rule order)
% o M_ [structure] decribing the model
% o oo_ [structure] storing the results
% o options_ [structure] describing the options
% o bayestopt_ [structure] describing the priors
%
% Notes:
% m: number of endogenous variables (M_.endo_nbr)
% T: number of Time periods (options_.nobs)
% r: number of strucural shocks (M_.exo_nbr)
% n: number of observables (length(options_.varobs))
% K: maximum forecast horizon (max(options_.nk))
%
% To get variables that are stored in decision rule order in order of declaration
% as in M_.endo_names, ones needs code along the lines of:
% variables_declaration_order(dr.order_var,:) = alphahat
%
% Defines bayestopt_.mf = bayestopt_.smoother_mf (positions of observed variables
% and requested smoothed variables in decision rules (decision rule order)) and
% passes it back via global variable
%
% ALGORITHM
% Diffuse Kalman filter (Durbin and Koopman)
%
% SPECIAL REQUIREMENTS
% None
% Copyright (C) 2006-2020 Dynare Team
%
% This file is part of Dynare.
%
% Dynare is free software: you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation, either version 3 of the License, or
% (at your option) any later version.
%
% Dynare is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with Dynare. If not, see <http://www.gnu.org/licenses/>.
alphahat = [];
etahat = [];
epsilonhat = [];
ahat = [];
SteadyState = [];
trend_coeff = [];
aK = [];
T = [];
R = [];
P = [];
PK = [];
decomp = [];
vobs = length(options_.varobs);
smpl = size(Y,2);
if ~isempty(xparam1) %not calibrated model
M_ = set_all_parameters(xparam1,estim_params_,M_);
end
%------------------------------------------------------------------------------
% 2. call model setup & reduction program
%------------------------------------------------------------------------------
oldoo.restrict_var_list = oo_.dr.restrict_var_list;
oldoo.restrict_columns = oo_.dr.restrict_columns;
oo_.dr.restrict_var_list = bayestopt_.smoother_var_list;
oo_.dr.restrict_columns = bayestopt_.smoother_restrict_columns;
[T,R,SteadyState,info,M_,options_,oo_] = dynare_resolve(M_,options_,oo_);
if info~=0
print_info(info,options_.noprint, options_);
return
end
oo_.dr.restrict_var_list = oldoo.restrict_var_list;
oo_.dr.restrict_columns = oldoo.restrict_columns;
%get location of observed variables and requested smoothed variables in
%decision rules
bayestopt_.mf = bayestopt_.smoother_var_list(bayestopt_.smoother_mf);
if options_.noconstant
constant = zeros(vobs,1);
else
if options_.loglinear
constant = log(SteadyState(bayestopt_.mfys));
else
constant = SteadyState(bayestopt_.mfys);
end
end
trend_coeff = zeros(vobs,1);
if bayestopt_.with_trend == 1
[trend_addition, trend_coeff] =compute_trend_coefficients(M_,options_,vobs,gend);
trend = constant*ones(1,gend)+trend_addition;
else
trend_addition=zeros(size(constant,1),gend);
trend = constant*ones(1,gend);
end
start = options_.presample+1;
np = size(T,1);
mf = bayestopt_.mf;
% ------------------------------------------------------------------------------
% 3. Initial condition of the Kalman filter
% ------------------------------------------------------------------------------
%
% Here, Pinf and Pstar are determined. If the model is stationary, determine
% Pstar as the solution of the Lyapunov equation and set Pinf=[] (Notation follows
% Koopman/Durbin (2003), Journal of Time Series Analysis 24(1))
%
Q = M_.Sigma_e;
H = M_.H;
if isequal(H,0)
H = zeros(vobs,vobs);
end
Z = zeros(vobs,size(T,2));
for i=1:vobs
Z(i,mf(i)) = 1;
end
expanded_state_vector_for_univariate_filter=0;
kalman_algo = options_.kalman_algo;
if options_.lik_init == 1 % Kalman filter
if kalman_algo ~= 2
kalman_algo = 1;
end
Pstar=lyapunov_solver(T,R,Q,options_);
Pinf = [];
elseif options_.lik_init == 2 % Old Diffuse Kalman filter
if kalman_algo ~= 2
kalman_algo = 1;
end
Pstar = options_.Harvey_scale_factor*eye(np);
Pinf = [];
elseif options_.lik_init == 3 % Diffuse Kalman filter
if kalman_algo ~= 4
kalman_algo = 3;
else
if ~all(all(abs(H-diag(diag(H)))<1e-14))% ie, the covariance matrix is diagonal...
%Augment state vector (follows Section 6.4.3 of DK (2012))
expanded_state_vector_for_univariate_filter=1;
T = blkdiag(T,zeros(vobs));
np = size(T,1);
Q = blkdiag(Q,H);
R = blkdiag(R,eye(vobs));
H = zeros(vobs,vobs);
Z = [Z, eye(vobs)];
end
end
[Pstar,Pinf] = compute_Pinf_Pstar(mf,T,R,Q,options_.qz_criterium);
elseif options_.lik_init == 4 % Start from the solution of the Riccati equation.
Pstar = kalman_steady_state(transpose(T),R*Q*transpose(R),transpose(build_selection_matrix(mf,np,vobs)),H);
Pinf = [];
if kalman_algo~=2
kalman_algo = 1;
end
elseif options_.lik_init == 5 % Old diffuse Kalman filter only for the non stationary variables
[eigenvect, eigenv] = eig(T);
eigenv = diag(eigenv);
nstable = length(find(abs(abs(eigenv)-1) > 1e-7));
unstable = find(abs(abs(eigenv)-1) < 1e-7);
V = eigenvect(:,unstable);
indx_unstable = find(sum(abs(V),2)>1e-5);
stable = find(sum(abs(V),2)<1e-5);
nunit = length(eigenv) - nstable;
Pstar = options_.Harvey_scale_factor*eye(np);
if kalman_algo ~= 2
kalman_algo = 1;
end
R_tmp = R(stable, :);
T_tmp = T(stable,stable);
Pstar_tmp=lyapunov_solver(T_tmp,R_tmp,Q,DynareOptions);
Pstar(stable, stable) = Pstar_tmp;
Pinf = [];
end
kalman_tol = options_.kalman_tol;
diffuse_kalman_tol = options_.diffuse_kalman_tol;
riccati_tol = options_.riccati_tol;
data1 = Y-trend;
% -----------------------------------------------------------------------------
% 4. Kalman smoother
% -----------------------------------------------------------------------------
if ~missing_value
for i=1:smpl
data_index{i}=(1:vobs)';
end
end
ST = T;
R1 = R;
if kalman_algo == 1 || kalman_algo == 3
[alphahat,epsilonhat,etahat,ahat,P,aK,PK,decomp,state_uncertainty] = missing_DiffuseKalmanSmootherH1_Z(ST, ...
Z,R1,Q,H,Pinf,Pstar, ...
data1,vobs,np,smpl,data_index, ...
options_.nk,kalman_tol,diffuse_kalman_tol,options_.filter_decomposition,options_.smoothed_state_uncertainty);
if isinf(alphahat)
if kalman_algo == 1
kalman_algo = 2;
elseif kalman_algo == 3
kalman_algo = 4;
else
error('This case shouldn''t happen')
end
end
end
if kalman_algo == 2 || kalman_algo == 4
if ~all(all(abs(H-diag(diag(H)))<1e-14))% ie, the covariance matrix is diagonal...
if ~expanded_state_vector_for_univariate_filter
%Augment state vector (follows Section 6.4.3 of DK (2012))
expanded_state_vector_for_univariate_filter=1;
Z = [Z, eye(vobs)];
ST = blkdiag(ST,zeros(vobs));
np = size(ST,1);
Q = blkdiag(Q,H);
R1 = blkdiag(R,eye(vobs));
if kalman_algo == 4
%recompute Schur state space transformation with
%expanded state space
[Pstar,Pinf] = compute_Pinf_Pstar(mf,ST,R1,Q,options_.qz_criterium);
else
Pstar = blkdiag(Pstar,H);
if ~isempty(Pinf)
Pinf = blkdiag(Pinf,zeros(vobs));
end
end
%now reset H to 0
H = zeros(vobs,vobs);
else
%do nothing, state vector was already expanded
end
end
[alphahat,epsilonhat,etahat,ahat,P,aK,PK,decomp,state_uncertainty] = missing_DiffuseKalmanSmootherH3_Z(ST, ...
Z,R1,Q,diag(H), ...
Pinf,Pstar,data1,vobs,np,smpl,data_index, ...
options_.nk,kalman_tol,diffuse_kalman_tol, ...
options_.filter_decomposition,options_.smoothed_state_uncertainty);
end
if expanded_state_vector_for_univariate_filter && (kalman_algo == 2 || kalman_algo == 4)
% extracting measurement errors
% removing observed variables from the state vector
k = (1:np-vobs);
alphahat = alphahat(k,:);
ahat = ahat(k,:);
aK = aK(:,k,:,:);
epsilonhat=etahat(end-vobs+1:end,:);
etahat=etahat(1:end-vobs,:);
if ~isempty(PK)
PK = PK(:,k,k,:);
end
if ~isempty(decomp)
decomp = decomp(:,k,:,:);
end
if ~isempty(P)
P = P(k,k,:);
end
if ~isempty(state_uncertainty)
state_uncertainty = state_uncertainty(k,k,:);
end
end