dynare/matlab/det_cond_forecast.m

358 lines
16 KiB
Matlab

function det_cond_forecast(constrained_paths, constrained_vars, options_cond_fcst, constrained_perfect_foresight)
% Computes conditional forecasts for a deterministic model.
%
% INPUTS
% o constrained_paths [double] m*p array, where m is the number of constrained endogenous variables and p is the number of constrained periods.
% o constrained_vars [char] m*x array holding the names of the controlled endogenous variables.
% o options_cond_fcst [structure] containing the options. The fields are:
% + replic [integer] scalar, number of monte carlo simulations.
% + parameter_set [char] values of the estimated parameters:
% "posterior_mode",
% "posterior_mean",
% "posterior_median",
% "prior_mode" or
% "prior mean".
% [double] np*1 array, values of the estimated parameters.
% + controlled_varexo [char] m*x array, list of controlled exogenous variables.
% + conf_sig [double] scalar in [0,1], probability mass covered by the confidence bands.
% o constrained_perfect_foresight [double] m*1 array indicating if the endogenous variables path is perfectly foresight (1) or is a surprise (0)
%
%
% OUTPUTS
% None.
%
% SPECIAL REQUIREMENTS
% This routine has to be called after an estimation statement or an estimated_params block.
%
% REMARKS
% [1] Results are stored in a structure which is saved in a mat file called conditional_forecasts.mat.
% [2] Use the function plot_icforecast to plot the results.
% Copyright (C) 2013 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/>.
global options_ oo_ M_
if ~isfield(options_cond_fcst,'periods') || isempty(options_cond_fcst.periods)
options_cond_fcst.periods = 100;
end
maximum_lag = M_.maximum_lag;
maximum_lead = M_.maximum_lead;
ys = oo_.steady_state;
ny = size(ys,1);
xs = [oo_.exo_steady_state ; oo_.exo_det_steady_state];
nx = size(xs,1);
constrained_periods = size(constrained_paths,2);
n_endo_constrained = size(constrained_vars,1);
if isfield(options_cond_fcst,'controlled_varexo')
n_control_exo = size(options_cond_fcst.controlled_varexo, 1);
if n_control_exo ~= n_endo_constrained
error(['det_cond_forecast:: the number of exogenous controlled variables (' int2str(n_control_exo) ') has to be equal to the number of constrained endogenous variabes (' int2str(n_endo_constrained) ')'])
end;
else
error('det_cond_forecast:: to run a deterministic conditional forecast you have to specified the exogenous variables controlled using the option controlled_varex in forecast command');
end;
exo_names = M_.exo_names;
controlled_varexo = zeros(1,n_control_exo);
for i = 1:nx
for j=1:n_control_exo
if strcmp(deblank(exo_names(i,:)), deblank(options_cond_fcst.controlled_varexo(j,:)))
controlled_varexo(j) = i;
end
end
end
%todo check if zero => error message
save_options_initval_file = options_.initval_file;
options_.initval_file = '__';
[pos_constrained_pf, junk] = find(constrained_perfect_foresight);
indx_endo_solve_pf = constrained_vars(pos_constrained_pf);
if isempty(indx_endo_solve_pf)
pf = 0;
else
pf = length(indx_endo_solve_pf);
end;
indx_endo_solve_surprise = setdiff(constrained_vars, indx_endo_solve_pf);
if isempty(indx_endo_solve_surprise)
surprise = 0;
else
surprise = length(indx_endo_solve_surprise);
end;
eps = options_.solve_tolf;
maxit = options_.simul.maxit;
initial_conditions = oo_.steady_state;
past_val = 0;
save_options_periods = options_.periods;
options_.periods = options_cond_fcst.periods;
save_options_dynatol_f = options_.dynatol.f;
options_.dynatol.f = 1e-8;
eps1 = 1e-4;
exo = zeros(maximum_lag + options_cond_fcst.periods, nx);
endo = zeros(maximum_lag + options_cond_fcst.periods, ny);
endo(1,:) = oo_.steady_state';
% if all the endogenous paths are perfectly anticipated we do not need to
% implement extended path
if pf && ~surprise
time_index_constraint = maximum_lag + 1:maximum_lag + constrained_periods;
second_system_size = pf * constrained_periods;
J = zeros(second_system_size,second_system_size);
r = zeros(second_system_size,1);
indx_endo = zeros(second_system_size,1);
col_count = 1;
for j = 1:length(constrained_vars)
indx_endo(col_count : col_count + constrained_periods - 1) = constrained_vars(j) + (time_index_constraint - 1) * ny;
col_count = col_count + constrained_periods;
end;
make_ex_;
make_y_;
it = 1;
convg = 0;
while ~convg && it <= maxit
disp('---------------------------------------------------------------------------------------------');
disp(['iteration ' int2str(it)]);
not_achieved = 1;
alpha = 1;
while not_achieved
simul();
result = sum(sum(isfinite(oo_.endo_simul(:,time_index_constraint)))) == ny * constrained_periods;
if (~oo_.deterministic_simulation.status || ~result) && it > 1
not_achieved = 1;
alpha = alpha / 2;
col_count = 1;
for j = controlled_varexo
oo_.exo_simul(time_index_constraint,j) = (old_exo(:,j) + alpha * D_exo(col_count: col_count + constrained_periods - 1));
col_count = col_count + constrained_periods;
end;
disp(['Divergence in Newton: reducing the path length alpha=' num2str(alpha)]);
oo_.endo_simul = repmat(oo_.steady_state, 1, options_cond_fcst.periods + 2);
else
not_achieved = 0;
end;
end;
y = oo_.endo_simul(constrained_vars(j), time_index_constraint);
ys = oo_.endo_simul(indx_endo);
col_count = 1;
for j = 1:length(constrained_vars)
y = oo_.endo_simul(constrained_vars(j), time_index_constraint);
r(col_count:col_count+constrained_periods - 1) = (y - constrained_paths(j,1:constrained_periods))';
col_count = col_count + constrained_periods;
end;
col_count = 1;
for j = controlled_varexo
for time = time_index_constraint
saved = oo_.exo_simul(time,j);
oo_.exo_simul(time,j) = oo_.exo_simul(time,j) + eps1;
simul();
J(:,col_count) = (oo_.endo_simul(indx_endo) - ys) / eps1;
oo_.exo_simul(time,j) = saved;
col_count = col_count + 1;
end;
end;
normr = norm(r, 1);
disp(['iteration ' int2str(it) ' error = ' num2str(normr)]);
if normr <= eps
convg = 1;
disp('convergence achieved');
else
% Newton update on exogenous shocks
old_exo = oo_.exo_simul(time_index_constraint,:);
D_exo = - J \ r;
col_count = 1;
for j = controlled_varexo
oo_.exo_simul(time_index_constraint,j) = (oo_.exo_simul(time_index_constraint,j) + D_exo(col_count: col_count + constrained_periods - 1));
col_count = col_count + constrained_periods;
end;
end;
it = it + 1;
end;
endo(maximum_lag + 1 :maximum_lag + options_cond_fcst.periods ,:) = oo_.endo_simul(:,maximum_lag + 1:maximum_lag + options_cond_fcst.periods )';
exo = oo_.exo_simul;
else
for t = 1:constrained_periods
disp('=============================================================================================');
disp(['t=' int2str(t) ' constrained_paths(:,t)=' num2str(constrained_paths(:,t)') ]);
disp('=============================================================================================');
if t == 1
make_ex_;
exo_init = oo_.exo_simul;
make_y_;
end;
oo_.exo_simul = exo_init;
oo_.endo_simul(:,1) = initial_conditions;
convg = 0;
it = 1;
time_index_constraint = maximum_lag + 1:maximum_lag + constrained_periods - t + 1;
second_system_size = surprise + pf * (constrained_periods - t + 1);
indx_endo = zeros(second_system_size,1);
col_count = 1;
for j = 1:length(constrained_vars)
if constrained_perfect_foresight(j)
indx_endo(col_count : col_count + constrained_periods - t) = constrained_vars(j) + (time_index_constraint - 1) * ny;
col_count = col_count + constrained_periods - t + 1;
else
indx_endo(col_count) = constrained_vars(j) + maximum_lag * ny;
col_count = col_count + 1;
end;
end;
J = zeros(second_system_size,second_system_size);
r = zeros(second_system_size,1);
while ~convg && it <= maxit
disp('---------------------------------------------------------------------------------------------');
disp(['iteration ' int2str(it) ' time ' int2str(t)]);
not_achieved = 1;
alpha = 1;
while not_achieved
simul();
result = sum(sum(isfinite(oo_.endo_simul(:,time_index_constraint)))) == ny * length(time_index_constraint);
if (~oo_.deterministic_simulation.status || ~result) && it > 1
not_achieved = 1;
alpha = alpha / 2;
col_count = 1;
for j = controlled_varexo
if constrained_perfect_foresight(j)
oo_.exo_simul(time_index_constraint,j) = (old_exo(time_index_constraint,j) + alpha * D_exo(col_count: col_count + constrained_periods - t));
col_count = col_count + constrained_periods - t + 1;
else
oo_.exo_simul(maximum_lag + 1,j) = old_exo(maximum_lag + 1,j) + alpha * D_exo(col_count);
col_count = col_count + 1;
end;
end;
disp(['Divergence in Newton: reducing the path length alpha=' num2str(alpha) ' result=' num2str(result) ' sum(sum)=' num2str(sum(sum(isfinite(oo_.endo_simul(:,time_index_constraint))))) ' ny * length(time_index_constraint)=' num2str(ny * length(time_index_constraint)) ' oo_.deterministic_simulation.status=' num2str(oo_.deterministic_simulation.status)]);
oo_.endo_simul = [initial_conditions repmat(oo_.steady_state, 1, options_cond_fcst.periods + 1)];
else
not_achieved = 0;
end;
end;
if t==constrained_periods
ycc = oo_.endo_simul;
end;
yc = oo_.endo_simul(:,maximum_lag + 1);
ys = oo_.endo_simul(indx_endo);
col_count = 1;
for j = 1:length(constrained_vars)
if constrained_perfect_foresight(j)
y = oo_.endo_simul(constrained_vars(j), time_index_constraint);
r(col_count:col_count+constrained_periods - t) = (y - constrained_paths(j,t:constrained_periods))';
col_count = col_count + constrained_periods - t + 1;
else
y = yc(constrained_vars(j));
r(col_count) = y - constrained_paths(j,t);
col_count = col_count + 1;
end;
end
disp('computation of derivatives w.r. to exogenous shocks');
col_count = 1;
for j = 1:length(controlled_varexo)
j_pos = controlled_varexo(j);
if constrained_perfect_foresight(j)
for time = time_index_constraint
saved = oo_.exo_simul(time,j_pos);
oo_.exo_simul(time,j_pos) = oo_.exo_simul(time,j_pos) + eps1;
simul();
J(:,col_count) = (oo_.endo_simul(indx_endo) - ys) / eps1;
oo_.exo_simul(time,j_pos) = saved;
col_count = col_count + 1;
end;
else
saved = oo_.exo_simul(maximum_lag+1,j_pos);
oo_.exo_simul(maximum_lag+1,j_pos) = oo_.exo_simul(maximum_lag+1,j_pos) + eps1;
simul();
J(:,col_count) = (oo_.endo_simul(indx_endo) - ys) / eps1;
oo_.exo_simul(maximum_lag+1,j_pos) = saved;
col_count = col_count + 1;
end;
end;
normr = norm(r, 1);
disp(['iteration ' int2str(it) ' error = ' num2str(normr) ' at time ' int2str(t)]);
if normr <= eps
convg = 1;
disp('convergence achieved');
else
% Newton update on exogenous shocks
D_exo = - J \ r;
old_exo = oo_.exo_simul;
col_count = 1;
for j = 1:length(controlled_varexo)
j_pos=controlled_varexo(j);
if constrained_perfect_foresight(j)
oo_.exo_simul(time_index_constraint,j_pos) = (oo_.exo_simul(time_index_constraint,j_pos) + D_exo(col_count: col_count + constrained_periods - t));
col_count = col_count + constrained_periods - t + 1;
else
oo_.exo_simul(maximum_lag + 1,j_pos) = oo_.exo_simul(maximum_lag + 1,j_pos) + D_exo(col_count);
col_count = col_count + 1;
end;
end;
end;
it = it + 1;
end;
if ~convg
error(['convergence not achived at time ' int2str(t) ' after ' int2str(it) ' iterations']);
end;
for j = 1:length(controlled_varexo)
j_pos=controlled_varexo(j);
if constrained_perfect_foresight(j)
% in case of mixed surprise and perfect foresight
% endogenous path at each date all the exogenous paths have to be
% stored. The paths are stacked in exo.
for time = time_index_constraint;
exo(past_val + time,j_pos) = oo_.exo_simul(time,j_pos);
end
else
exo(maximum_lag + t,j_pos) = oo_.exo_simul(maximum_lag + 1,j_pos);
end;
end;
past_val = past_val + length(time_index_constraint);
if t < constrained_periods
endo(maximum_lag + t,:) = yc;
else
endo(maximum_lag + t :maximum_lag + options_cond_fcst.periods ,:) = ycc(:,maximum_lag + 1:maximum_lag + options_cond_fcst.periods - constrained_periods + 1)';
end;
initial_conditions = yc;
end;
end;
options_.periods = save_options_periods;
options_.dynatol.f = save_options_dynatol_f;
options_.initval_file = save_options_initval_file;
% disp('endo');
% disp(endo);
% disp('exo');
% disp(exo);
oo_.endo_simul = endo';
oo_.exo_simul = exo;