dynare/matlab/+mom/standard_errors.m

119 lines
5.8 KiB
Matlab

function [SE_values, Asympt_Var] = standard_errors(xparam, objective_function, Bounds, oo_, estim_params_, M_, options_mom_, Wopt_flag)
% [SE_values, Asympt_Var] = standard_errors(xparam, objective_function, Bounds, oo_, estim_params_, M_, options_mom_, Wopt_flag)
% -------------------------------------------------------------------------
% This function computes standard errors to the method of moments estimates
% Adapted from replication codes of
% o 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 xparam: value of estimated parameters as returned by set_prior()
% o objective_function string of objective function
% o Bounds: structure containing parameter bounds
% o oo_: structure for results
% o estim_params_: structure describing the estimated_parameters
% o M_ structure describing the model
% o options_mom_: structure information about all settings (specified by the user, preprocessor, and taken from global options_)
% o Wopt_flag: indicator whether the optimal weighting is actually used
% -------------------------------------------------------------------------
% OUTPUTS
% o SE_values [nparam x 1] vector of standard errors
% o Asympt_Var [nparam x nparam] asymptotic covariance matrix
% -------------------------------------------------------------------------
% This function is called by
% o mom.run.m
% -------------------------------------------------------------------------
% This function calls:
% o get_the_name
% o get_error_message
% o mom.objective_function
% o mom.optimal_weighting_matrix
% =========================================================================
% Copyright © 2020-2021 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/>.
% -------------------------------------------------------------------------
% Author(s):
% o Willi Mutschler (willi@mutschler.eu)
% o Johannes Pfeifer (jpfeifer@uni-koeln.de)
% =========================================================================
% Some dimensions
num_mom = size(oo_.mom.model_moments,1);
dim_params = size(xparam,1);
D = zeros(num_mom,dim_params);
eps_value = options_mom_.mom.se_tolx;
if strcmp(options_mom_.mom.mom_method,'GMM') && options_mom_.mom.analytic_standard_errors
fprintf('\nComputing standard errors using analytical derivatives of moments\n');
D = oo_.mom.model_moments_params_derivs; %already computed in objective function via get_perturbation_params.m
idx_nan = find(any(isnan(D)));
if any(idx_nan)
for i = idx_nan
fprintf('No standard errors available for parameter %s\n',get_the_name(i,options_mom_.TeX, M_, estim_params_, options_mom_))
end
warning('There are NaN in the analytical Jacobian of Moments. Check your bounds and/or priors, or use a different optimizer.')
Asympt_Var = NaN(length(xparam),length(xparam));
SE_values = NaN(length(xparam),1);
return
end
else
fprintf('\nComputing standard errors using numerical derivatives of moments\n');
for i=1:dim_params
%Positive step
xparam_eps_p = xparam;
xparam_eps_p(i,1) = xparam_eps_p(i) + eps_value;
[~, info_p, ~, ~,~, oo__p] = feval(objective_function, xparam_eps_p, Bounds, oo_, estim_params_, M_, options_mom_);
% Negative step
xparam_eps_m = xparam;
xparam_eps_m(i,1) = xparam_eps_m(i) - eps_value;
[~, info_m, ~, ~,~, oo__m] = feval(objective_function, xparam_eps_m, Bounds, oo_, estim_params_, M_, options_mom_);
% The Jacobian:
if nnz(info_p)==0 && nnz(info_m)==0
D(:,i) = (oo__p.mom.model_moments - oo__m.mom.model_moments)/(2*eps_value);
else
problpar = get_the_name(i,options_mom_.TeX, M_, estim_params_, options_mom_);
message_p = get_error_message(info_p, options_mom_);
message_m = get_error_message(info_m, options_mom_);
warning('method_of_moments:info','Cannot compute the Jacobian for parameter %s - no standard errors available\n %s %s\nCheck your bounds and/or priors, or use a different optimizer.\n',problpar, message_p, message_m)
Asympt_Var = NaN(length(xparam),length(xparam));
SE_values = NaN(length(xparam),1);
return
end
end
end
T = options_mom_.nobs; %Number of observations
if isfield(options_mom_,'variance_correction_factor')
T = T*options_mom_.variance_correction_factor;
end
WW = oo_.mom.Sw'*oo_.mom.Sw;
if Wopt_flag
% We have the optimal weighting matrix
Asympt_Var = 1/T*((D'*WW*D)\eye(dim_params));
else
% We do not have the optimal weighting matrix yet
WWopt = mom.optimal_weighting_matrix(oo_.mom.m_data, oo_.mom.model_moments, options_mom_.mom.bartlett_kernel_lag);
S = WWopt\eye(size(WWopt,1));
AA = (D'*WW*D)\eye(dim_params);
Asympt_Var = 1/T*AA*D'*WW*S*WW*D*AA;
end
SE_values = sqrt(diag(Asympt_Var));