dynare/matlab/dyn_ramsey_static.m

152 lines
4.5 KiB
Matlab

function [steady_state,params,check] = dyn_ramsey_static(x,M,options_,oo)
% function [steady_state,params,check] = dyn_ramsey_static_(x)
% Computes the static first order conditions for optimal policy
%
% INPUTS
% x: vector of endogenous variables or instruments
%
% OUTPUTS
% resids: residuals of non linear equations
% rJ: Jacobian
% mult: Lagrangian multipliers
%
% SPECIAL REQUIREMENTS
% none
% Copyright (C) 2003-2010 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/>.
steady_state = [];
params = M.params;
check = 0;
nl_func = @(x) dyn_ramsey_static_1(x,M,options_,oo);
if options_.steadystate_flag
k_inst = [];
instruments = options_.instruments;
inst_nbr = size(options_.instruments);
for i = 1:inst_nbr
k_inst = [k_inst; strmatch(options_.instruments(i,:), ...
M.endo_names,'exact')];
end
ys = oo.steady_state;
if inst_nbr == 1
inst_val = csolve(nl_func,oo_.steady_state(k_inst),'',options_.solve_tolf,100);
else
[inst_val,info1] = dynare_solve(nl_func,ys(k_inst),0);
end
ys(k_inst) = inst_val;
[x,params,check] = evaluate_steadystate_file(ys,exo_ss,params,M.fname,options_.steadystate_flag);
if size(x,1) < M.endo_nbr
if length(M.aux_vars) > 0
x = feval([M.fname '_set_auxiliary_variables'],xx,...
[oo.exo_steady_state,...
oo.exo_det_steady_state],...
M.params);
else
error([M.fname '_steadystate.m doesn''t match the model']);
end
end
[junk,junk,multbar] = dyn_ramsey_static_1(x(k_inst),M,options_,oo_);
steady_state = [x(1:M.orig_endo_nbr); multbar];
else
xx = oo.steady_state(1:M.orig_endo_nbr);
[xx,info1] = dynare_solve(nl_func,xx,0);
[junk,junk,multbar] = nl_func(xx);
steady_state = [xx; multbar];
end
function [resids, rJ,mult] = dyn_ramsey_static_1(x,M,options_,oo)
resids = [];
rJ = [];
mult = [];
% recovering usefull fields
endo_nbr = M.endo_nbr;
exo_nbr = M.exo_nbr;
orig_endo_nbr = M.orig_endo_nbr;
orig_eq_nbr = M.orig_eq_nbr;
inst_nbr = orig_endo_nbr - orig_eq_nbr;
% indices of Lagrange multipliers
i_mult = [orig_endo_nbr+(1:orig_eq_nbr)]';
fname = M.fname;
max_lead = M.maximum_lead;
max_lag = M.maximum_lag;
% 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]);
end
% setting steady state of auxiliary variables
xx = zeros(endo_nbr,1);
xx(1:orig_endo_nbr) = x(1:orig_endo_nbr);
x = feval([M.fname '_set_auxiliary_variables'],xx,...
[oo.exo_steady_state,...
oo.exo_det_steady_state],...
M.params);
% value and Jacobian of objective function
ex = zeros(1,M.exo_nbr);
[U,Uy,Uyy] = feval([fname '_objective_static'],x,ex, M.params);
Uy = Uy';
Uyy = reshape(Uyy,endo_nbr,endo_nbr);
% set multipliers to 0 to compute residuals
[f,fJ] = feval([fname '_static'],x,[oo.exo_simul oo.exo_det_simul], ...
M.params);
aux_eq = [1:orig_endo_nbr orig_endo_nbr+orig_eq_nbr+1:size(fJ,1)];
A = fJ(aux_eq,orig_endo_nbr+1:end);
y = f(aux_eq);
mult = -A\y;
resids1 = y+A*mult;
if inst_nbr == 1
r1 = sqrt(resids1'*resids1);
else
[q,r,e] = qr([A y]');
r1 = r(end,(orig_endo_nbr-inst_nbr+1:end))';
end
if options_.steadystate_flag
resids = r1;
else
resids = [f(i_mult); r1];
end
rJ = [];