Make rool for trend_component_model in var_expectation.

Not yet working, a bug in the preprocessor remains to be fixed. The
preprocessor does not create the correct number of reduced form parameters
for VAR_EXPECTATION when the auxiliary model is a trend component model,
because it ignores the fact that the model has to be rewritten in levels.
time-shift
Stéphane Adjemia (Scylla) 2018-08-27 14:37:26 +02:00
parent e25b6a0a18
commit 83c9b0d5b6
8 changed files with 152 additions and 30 deletions

View File

@ -44,23 +44,23 @@ end
varexpectationmodel = DynareModel.var_expectation.(varexpectationmodelname);
% Get the name of the associated VAR model and test its existence.
if ~isfield(DynareModel.var, varexpectationmodel.auxiliary_model_name)
if ~isfield(DynareModel.(varexpectationmodel.auxiliary_model_type), varexpectationmodel.auxiliary_model_name)
error('Unknown VAR (%s) in VAR_EXPECTATION_MODEL (%s)!', varexpectationmodel.auxiliary_model_name, varexpectationmodelname)
end
varmodel = DynareModel.var.(varexpectationmodel.auxiliary_model_name);
auxmodel = DynareModel.(varexpectationmodel.auxiliary_model_type).(varexpectationmodel.auxiliary_model_name);
% Check that we have the values of the VAR matrices.
if ~isfield(DynareOutput.var, varexpectationmodel.auxiliary_model_name)
error('VAR model %s has to be estimated or calibrated first!', varexpectationmodel.auxiliary_model_name)
if ~isfield(DynareOutput.(varexpectationmodel.auxiliary_model_type), varexpectationmodel.auxiliary_model_name)
error('Auxiliary model %s has to be estimated or calibrated first!', varexpectationmodel.auxiliary_model_name)
end
varcalib = DynareOutput.var.(varexpectationmodel.auxiliary_model_name);
auxcalib = DynareOutput.(varexpectationmodel.auxiliary_model_type).(varexpectationmodel.auxiliary_model_name);
if ~isfield(varcalib, 'CompanionMatrix') || any(isnan(varcalib.CompanionMatrix(:)))
message = sprintf('VAR model %s has to be estimated first.', varexpectationmodel.auxiliary_model_name);
message = sprintf('s\nPlease use get_companion_matrix command first.', message);
error(message)
if ~isfield(auxcalib, 'CompanionMatrix') || any(isnan(auxcalib.CompanionMatrix(:)))
message = sprintf('Auxiliary model %s has to be estimated first.', varexpectationmodel.auxiliary_model_name);
message = sprintf('%s\nPlease use get_companion_matrix command first.', message);
error(message);
end
% Set discount factor
@ -85,7 +85,7 @@ if discountfactor>1
end
% Set variable_id in VAR model
variable_id_in_var = find(varexpectationmodel.variable_id==varmodel.lhs);
variable_id_in_var = find(varexpectationmodel.variable_id==auxmodel.lhs);
% Get the horizon parameter.
horizon = varexpectationmodel.horizon;
@ -121,7 +121,7 @@ if wrong_horizon_parameter
end
% Get the companion matrix
CompanionMatrix = varcalib.CompanionMatrix;
CompanionMatrix = auxcalib.CompanionMatrix;
% Get the dimension of the problem.
n = length(CompanionMatrix);

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@ -0,0 +1,45 @@
function initialize(varexpectationmodel)
% Initialize a VAR_EXPECTATION_MODEL.
%
% INPUTS
% - varepxpectationmodel [string] Name of the VAR expectation model.
%
% OUTPUTS
% None
%
% SPECIAL REQUIREMENTS
% none
% Copyright (C) 2018 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_
auxiliary_model_name = M_.var_expectation.(varexpectationmodel).auxiliary_model_name;
if isfield(M_, 'var') && isfield(M_.var, auxiliary_model_name)
auxiliary_model_type = 'var';
elseif isfield(M_, 'trend_component') && isfield(M_.trend_component, auxiliary_model_name)
auxiliary_model_type = 'trend_component';
else
error('Unknown type of auxiliary model.')
end
M_.var_expectation.(varexpectationmodel).auxiliary_model_type = auxiliary_model_type;
get_companion_matrix(auxiliary_model_name, auxiliary_model_type);

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@ -51,9 +51,8 @@ foo = .5*foo(-1) + var_expectation(varexp);
end;
// Build the companion matrix of the VAR model (toto).
get_companion_matrix('toto');
// Initialize the VAR expectation model, will build the companion matrix of the VAR.
var_expectation.initialize('varexp')
// Update VAR_EXPECTATION reduced form parameters
var_expectation.update('varexp');

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@ -51,9 +51,8 @@ foo = .5*foo(-1) + var_expectation(varexp);
end;
// Build the companion matrix of the VAR model (toto).
get_companion_matrix('toto');
// Initialize the VAR expectation model, will build the companion matrix of the VAR.
var_expectation.initialize('varexp')
// Update VAR_EXPECTATION reduced form parameters
var_expectation.update('varexp');

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@ -50,10 +50,8 @@ y = d*y(-2) + e*z(-1) + e_y;
foo = .5*foo(-1) + var_expectation(varexp);
end;
// Build the companion matrix of the VAR model (toto).
get_companion_matrix('toto');
// Initialize the VAR expectation model, will build the companion matrix of the VAR.
var_expectation.initialize('varexp')
// Update VAR_EXPECTATION reduced form parameters
var_expectation.update('varexp');

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@ -50,10 +50,8 @@ y = d*y(-2) + e*z(-1) + e_y;
foo = .5*foo(-1) + var_expectation(varexp);
end;
// Build the companion matrix of the VAR model (toto).
get_companion_matrix('toto');
// Initialize the VAR expectation model, will build the companion matrix of the VAR.
var_expectation.initialize('varexp')
// Update VAR_EXPECTATION reduced form parameters
var_expectation.update('varexp');

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@ -38,7 +38,6 @@ var_model(model_name = toto, eqtags = [ 'X' 'Y' 'Z' ]);
var_expectation_model(model_name = varexp, variable = x, auxiliary_model_name = toto, horizon = 15:50, discount = beta) ;
model;
[ name = 'X' ]
x = a*x(-1) + b*x(-2) + c*z(-2) + e_x;
@ -50,10 +49,8 @@ y = d*y(-2) + e*z(-1) + e_y;
foo = .5*foo(-1) + var_expectation(varexp);
end;
// Build the companion matrix of the VAR model (toto).
get_companion_matrix('toto');
// Initialize the VAR expectation model, will build the companion matrix of the VAR.
var_expectation.initialize('varexp')
// Update VAR_EXPECTATION reduced form parameters
var_expectation.update('varexp');

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@ -0,0 +1,86 @@
// --+ options: stochastic,json=compute +--
var foo x1 x2 x1bar x2bar;
varexo ex1 ex2 ex1bar ex2bar;
parameters a_x1_0 a_x1_0_ a_x1_1 a_x1_2 a_x1_x2_1 a_x1_x2_2
a_x2_0 a_x2_1 a_x2_2 a_x2_x1_1 a_x2_x1_2
beta ;
a_x1_0 = -.9;
a_x1_0_ = -.8;
a_x1_1 = .4;
a_x1_2 = .3;
a_x1_x2_1 = .1;
a_x1_x2_2 = .2;
a_x2_0 = -.9;
a_x2_1 = .2;
a_x2_2 = -.1;
a_x2_x1_1 = -.1;
a_x2_x1_2 = .2;
beta = 1/(1+.02);
// Define a TREND_COMPONENT model from a subset of equations in the model block.
trend_component_model(model_name=toto, eqtags=['eq:x1', 'eq:x2', 'eq:x1bar', 'eq:x2bar'], trends=['eq:x1bar', 'eq:x2bar']);
/* Define a VAR_EXPECTATION_MODEL
** ------------------------------
**
** model_name: the name of the VAR_EXPECTATION_MODEL (mandatory).
** auxiliary_model_name: the name of the VAR model used for the expectations (mandatory).
** variable: the name of the variable to be forecasted (mandatory).
** horizon: the horizon forecast (mandatory).
** discount: the discount factor, which can be a value or a declared parameter (default is 1.0, no discounting).
**
**
** The `horizon` parameter can be an integer in which case the (discounted) `horizon` step ahead forecast
** is computed using the VAR model `var_model_name`. Alternatively, `horizon` can be a range. In this case
** VAR_EXPECTATION_MODEL returns a discounted sum of expected values. If `horizon` is set equal to the range
** 0:Inf, then VAR_EXPECTATION_MODEL computes:
**
** βʰ E[y]
**
** where the sum is over h=0,, and the conditional expectations are computed with VAR model `var_model_name`.
*/
var_expectation_model(model_name = varexp, variable = x1bar, auxiliary_model_name = toto, horizon = 15:50, discount = beta) ;
model;
[name='eq:x1', data_type='nonstationary']
diff(x1) = a_x1_0*(x1(-1)-x1bar(-1))+a_x1_0_*(x2(-1)-x2bar(-1)) + a_x1_1*diff(x1(-1)) + a_x1_2*diff(x1(-2)) + + a_x1_x2_1*diff(x2(-1)) + a_x1_x2_2*diff(x2(-2)) + ex1;
[name='eq:x2', data_type='nonstationary']
diff(x2) = a_x2_0*(x2(-1)-x2bar(-1)) + a_x2_1*diff(x1(-1)) + a_x2_2*diff(x1(-2)) + + a_x2_x1_1*diff(x2(-1)) + a_x2_x1_2*diff(x2(-2)) + ex2;
[name='eq:x1bar', data_type='nonstationary']
x1bar = x1bar(-1) + ex1bar;
[name='eq:x2bar', data_type='nonstationary']
x2bar = x2bar(-1) + ex2bar;
foo = .5*foo(-1) + var_expectation(varexp);
end;
// Initialize the VAR expectation model, will build the companion matrix of the VAR.
var_expectation.initialize('varexp')
// Update VAR_EXPECTATION reduced form parameters
var_expectation.update('varexp');
/*
** REMARK The VAR model is such that x depends on past values of x
** (x and x) and on z. Consequently the reduced
** form parameters associated to y, y have to be zero.
*/
weights = M_.params(M_.var_expectation.varexp.param_indices);
if weights(2) || ~weights(3) || weights(5) || ~weights(1) || ~weights(4) || ~weights(6)
error('Wrong reduced form parameter for VAR_EXPECTATION_MODEL')
end