dynare/matlab/dyn_ramsey_static_.m

138 lines
4.7 KiB
Matlab

function [resids, rJ,mult] = dyn_ramsey_static_(x,M_,options_,oo_,it_)
% function [resids, rJ,mult] = dyn_ramsey_static_(x)
% Computes the static first order conditions for optimal policy
%
% INPUTS
% x: vector of endogenous variables
%
% OUTPUTS
% resids: residuals of non linear equations
% rJ: Jacobian
% mult: Lagrangian multipliers
%
% SPECIAL REQUIREMENTS
% none
% Copyright (C) 2003-2007 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/>.
% recovering usefull fields
endo_nbr = M_.endo_nbr;
exo_nbr = M_.exo_nbr;
fname = M_.fname;
% inst_nbr = M_.inst_nbr;
% i_endo_no_inst = M_.endogenous_variables_without_instruments;
max_lead = M_.maximum_lead;
max_lag = M_.maximum_lag;
beta = options_.planner_discount;
% indices of all endogenous variables
i_endo = [1:endo_nbr]';
% indices of endogenous variable except instruments
% i_inst = M_.instruments;
% lead_lag incidence matrix for endogenous variables
i_lag = M_.lead_lag_incidence;
if options_.steadystate_flag
k_inst = [];
instruments = options_.instruments;
for i = 1:size(instruments,1)
k_inst = [k_inst; strmatch(options_.instruments(i,:), ...
M_.endo_names,'exact')];
end
oo_.steady_state(k_inst) = x;
[x,check] = feval([M_.fname '_steadystate'],...
oo_.steady_state,...
[oo_.exo_steady_state; ...
oo_.exo_det_steady_state]);
if size(x,1) < M_.endo_nbr
if length(M_.aux_vars) > 0
x = add_auxiliary_variables_to_steadystate(x,M_.aux_vars,...
M_.fname,...
oo_.exo_steady_state,...
oo_.exo_det_steady_state,...
M_.params);
else
error([M_.fname '_steadystate.m doesn''t match the model']);
end
end
end
% value and Jacobian of objective function
ex = zeros(1,M_.exo_nbr);
[U,Uy,Uyy] = feval([fname '_objective_static'],x(i_endo),ex, M_.params);
Uy = Uy';
Uyy = reshape(Uyy,endo_nbr,endo_nbr);
y = repmat(x(i_endo),1,max_lag+max_lead+1);
% value and Jacobian of dynamic function
k = find(i_lag');
it_ = 1;
% [f,fJ,fH] = feval([fname '_dynamic'],y(k),ex);
[f,fJ] = feval([fname '_dynamic'],y(k),[oo_.exo_simul oo_.exo_det_simul], M_.params, it_);
% indices of Lagrange multipliers
inst_nbr = endo_nbr - size(f,1);
i_mult = [endo_nbr+1:2*endo_nbr-inst_nbr]';
% derivatives of Lagrangian with respect to endogenous variables
% res1 = Uy;
A = zeros(endo_nbr,endo_nbr-inst_nbr);
for i=1:max_lag+max_lead+1
% select variables present in the model at a given lag
[junk,k1,k2] = find(i_lag(i,:));
% res1(k1) = res1(k1) + beta^(max_lag-i+1)*fJ(:,k2)'*x(i_mult);
A(k1,:) = A(k1,:) + beta^(max_lag-i+1)*fJ(:,k2)';
end
% i_inst = var_index(options_.olr_inst);
% k = setdiff(1:size(A,1),i_inst);
% mult = -A(k,:)\Uy(k);
mult = -A\Uy;
% resids = [f; Uy(i_inst)+A(i_inst,:)*mult];
resids1 = Uy+A*mult;
% resids = [f; sqrt(resids1'*resids1/endo_nbr)];
[q,r,e] = qr([A Uy]');
if options_.steadystate_flag
resids = [r(end,(endo_nbr-inst_nbr+1:end))'];
else
resids = [f; r(end,(endo_nbr-inst_nbr+1:end))'];
end
rJ = [];
return;
% Jacobian of first order conditions
n = nnz(i_lag)+exo_nbr;
iH = reshape(1:n^2,n,n);
rJ = zeros(2*endo_nbr-inst_nbr,2*endo_nbr-inst_nbr);
rJ(i_endo,i_endo) = Uyy;
for i=1:max_lag+max_lead+1
% select variables present in the model at a given lag
[junk,k1,k2] = find(i_lag(i,:));
k3 = length(k2);
rJ(k1,k1) = rJ(k1,k1) + beta^(max_lag-i+1)*reshape(fH(:,iH(k2,k2))'*x(i_mult),k3,k3);
rJ(k1,i_mult) = rJ(k1,i_mult) + beta^(max_lag-1+1)*fJ(:,k2)';
rJ(i_mult,k1) = rJ(i_mult,k1) + fJ(:,k2);
end
% rJ = 1e-3*rJ;
% rJ(209,210) = rJ(209,210)+1-1e-3;