2017-05-18 15:41:46 +02:00
|
|
|
function forecasts = backward_model_forecast(initialcondition, listofvariables, periods, withuncertainty)
|
|
|
|
|
|
|
|
% Returns unconditional forecasts.
|
|
|
|
%
|
|
|
|
% INPUTS
|
|
|
|
% - initialcondition [dseries] Initial conditions for the endogenous variables.
|
|
|
|
% - periods [integer] scalar, the number of (forecast) periods.
|
|
|
|
% - withuncertainty [logical] scalar, returns confidence bands if true.
|
|
|
|
%
|
|
|
|
% OUTPUTS
|
|
|
|
% - forecast [dseries]
|
|
|
|
|
|
|
|
% Copyright (C) 2017 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 M_ options_ oo_
|
|
|
|
|
|
|
|
% Check that the model is actually backward
|
|
|
|
if M_.maximum_lead
|
|
|
|
error(['backward_model_irf:: The specified model is not backward looking!'])
|
|
|
|
end
|
|
|
|
|
|
|
|
% Initialize returned argument.
|
|
|
|
forecasts = struct();
|
|
|
|
|
|
|
|
% Set defaults.
|
|
|
|
if nargin<2
|
|
|
|
listofvariables = cellstr(M_.endo_names);
|
|
|
|
periods = 8;
|
|
|
|
withuncertainty = false;
|
|
|
|
end
|
|
|
|
|
|
|
|
if nargin<3
|
|
|
|
periods = 8;
|
|
|
|
withuncertainty = false;
|
|
|
|
end
|
|
|
|
|
|
|
|
if nargin<4
|
|
|
|
withuncertainty = false;
|
|
|
|
end
|
|
|
|
|
|
|
|
% Get full list of endogenous variables
|
|
|
|
endo_names = cellstr(M_.endo_names);
|
|
|
|
|
|
|
|
% Get vector of indices for the selected endogenous variables.
|
|
|
|
n = length(listofvariables);
|
|
|
|
idy = zeros(n,1);
|
|
|
|
for i=1:n
|
2017-08-10 13:26:47 +02:00
|
|
|
j = find(strcmp(listofvariables{i}, endo_names));
|
2017-05-18 15:41:46 +02:00
|
|
|
if isempty(j)
|
|
|
|
error('backward_model_forecast:: Variable %s is unknown!', listofvariables{i})
|
|
|
|
else
|
|
|
|
idy(i) = j;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
|
|
|
% Set the number of simulations (if required).
|
|
|
|
if withuncertainty
|
|
|
|
B = 1000;
|
|
|
|
end
|
|
|
|
|
|
|
|
% Get the covariance matrix of the shocks.
|
|
|
|
if withuncertainty
|
|
|
|
Sigma = M_.Sigma_e + 1e-14*eye(M_.exo_nbr);
|
|
|
|
sigma = transpose(chol(Sigma));
|
|
|
|
end
|
|
|
|
|
2017-06-01 15:16:00 +02:00
|
|
|
% Set initial condition.
|
|
|
|
if isdates(initialcondition)
|
|
|
|
if isempty(M_.endo_histval)
|
|
|
|
error('backward_model_irf: histval block for setting initial condition is missing!')
|
|
|
|
end
|
|
|
|
initialcondition = dseries(transpose(M_.endo_histval), initialcondition, endo_names, cellstr(M_.endo_names_tex));
|
|
|
|
end
|
|
|
|
|
2017-05-18 15:41:46 +02:00
|
|
|
% Put initial conditions in a vector of doubles
|
|
|
|
initialconditions = transpose(initialcondition{endo_names{:}}.data);
|
|
|
|
|
|
|
|
% Compute forecast without shock
|
2017-08-11 11:47:34 +02:00
|
|
|
innovations = zeros(periods+M_.maximum_exo_lag, M_.exo_nbr);
|
2017-06-01 15:16:00 +02:00
|
|
|
if M_.maximum_exo_lag
|
|
|
|
if isempty(M_.exo_histval)
|
|
|
|
error('You need to set the past values for the exogenous variables!')
|
|
|
|
else
|
|
|
|
innovations(1:M_.maximum_exo_lag, :) = M_.exo_histval;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
2017-05-18 15:41:46 +02:00
|
|
|
oo__0 = simul_backward_model(initialconditions, periods, options_, M_, oo_, innovations);
|
|
|
|
forecasts.pointforecast = dseries(transpose(oo__0.endo_simul(idy,:)), initialcondition.init, listofvariables);
|
|
|
|
|
|
|
|
if withuncertainty
|
|
|
|
% Preallocate an array gathering the simulations.
|
2017-08-11 11:47:34 +02:00
|
|
|
ArrayOfForecasts = zeros(n, periods+size(initialconditions, 2), B);
|
2017-05-18 15:41:46 +02:00
|
|
|
for i=1:B
|
2017-08-11 11:47:34 +02:00
|
|
|
innovations(M_.maximum_exo_lag+1:end,:) = transpose(sigma*randn(M_.exo_nbr, periods));
|
2017-05-18 15:41:46 +02:00
|
|
|
oo__ = simul_backward_model(initialconditions, periods, options_, M_, oo_, innovations);
|
|
|
|
ArrayOfForecasts(:,:,i) = oo__.endo_simul(idy,:);
|
|
|
|
end
|
|
|
|
% Compute mean (over future uncertainty) forecast.
|
|
|
|
forecasts.meanforecast = dseries(transpose(mean(ArrayOfForecasts, 3)), initialcondition.init, listofvariables);
|
|
|
|
forecasts.medianforecast = dseries(transpose(median(ArrayOfForecasts, 3)), initialcondition.init, listofvariables);
|
|
|
|
forecasts.stdforecast = dseries(transpose(std(ArrayOfForecasts, 1,3)), initialcondition.init, listofvariables);
|
|
|
|
% Compute lower and upper 95% confidence bands
|
|
|
|
ArrayOfForecasts = sort(ArrayOfForecasts, 3);
|
|
|
|
forecasts.lb = dseries(transpose(ArrayOfForecasts(:,:,round(0.025*B))), initialcondition.init, listofvariables);
|
|
|
|
forecasts.ub = dseries(transpose(ArrayOfForecasts(:,:,round(0.975*B))), initialcondition.init, listofvariables);
|
|
|
|
end
|