dynare/matlab/+mom/optimal_weighting_matrix.m

78 lines
3.1 KiB
Matlab

function W_opt = optimal_weighting_matrix(m_data, moments, q_lag)
% W_opt = optimal_weighting_matrix(m_data, moments, q_lag)
% -------------------------------------------------------------------------
% This function computes the optimal weigthing matrix by a Bartlett kernel with maximum lag q_lag
% Adapted from replication codes of Andreasen, Fernández-Villaverde, Rubio-Ramírez (2018):
% "The Pruned State-Space System for Non-Linear DSGE Models: Theory and Empirical Applications",
% Review of Economic Studies, 85(1):1-49.
% -------------------------------------------------------------------------
% INPUTS
% o m_data [T x numMom] selected data moments at each point in time
% o moments [numMom x 1] selected estimated moments (either data_moments or estimated model_moments)
% o q_lag [integer] Bartlett kernel maximum lag order
% -------------------------------------------------------------------------
% OUTPUTS
% o W_opt [numMom x numMom] optimal weighting matrix
% -------------------------------------------------------------------------
% This function is called by
% o mom.run.m
% -------------------------------------------------------------------------
% This function calls:
% o corr_matrix (embedded)
% -------------------------------------------------------------------------
% Copyright © 2020-2023 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 <https://www.gnu.org/licenses/>.
% initialize
[T,num_Mom] = size(m_data); % note that in m_data NaN values (due to leads or lags in matched_moments and missing data) were replaced by the mean
% center around moments (could be either data_moments or model_moments)
h_func = m_data - repmat(moments',T,1);
% the required correlation matrices
gamma_array = zeros(num_Mom,num_Mom,q_lag);
gamma0 = corr_matrix(h_func,T,num_Mom,0);
if q_lag > 0
for ii=1:q_lag
gamma_array(:,:,ii) = corr_matrix(h_func,T,num_Mom,ii);
end
end
% the estimate of S
S = gamma0;
if q_lag > 0
for ii=1:q_lag
S = S + (1-ii/(q_lag+1))*(gamma_array(:,:,ii) + gamma_array(:,:,ii)');
end
end
% the estimate of W
W_opt = S\eye(size(S,1));
W_opt = (W_opt+W_opt')/2; % ensure symmetry
end % main function end
% The correlation matrix
function gamma_corr = corr_matrix(h_func,T,num_Mom,v)
gamma_corr = zeros(num_Mom,num_Mom);
for t = 1+v:T
gamma_corr = gamma_corr + h_func(t-v,:)'*h_func(t,:);
end
gamma_corr = gamma_corr/T;
end % corr_matrix end