82 lines
1.6 KiB
Modula-2
82 lines
1.6 KiB
Modula-2
var y i pi ;
|
|
|
|
varexo e;
|
|
|
|
parameters a1 a2 a3 a4 a5;
|
|
|
|
a1 = -.5;
|
|
a2 = .1;
|
|
a3 = .9;
|
|
a4 = 1.5;
|
|
a5 = 0.5;
|
|
|
|
model;
|
|
|
|
y = y(1)+a1*(i-pi(1))+e;
|
|
|
|
pi = a2*y + a3*pi(1);
|
|
|
|
i = max(0, a4*pi+a5*y);
|
|
|
|
end;
|
|
|
|
steady_state_model;
|
|
y=0;
|
|
i=0;
|
|
pi=0;
|
|
end;
|
|
|
|
steady;
|
|
check;
|
|
|
|
shocks;
|
|
var e;
|
|
periods 1 2;
|
|
values .3 -0.1;
|
|
end;
|
|
|
|
perfect_foresight_setup(periods=5);
|
|
perfect_foresight_solver;
|
|
|
|
if ~oo_.deterministic_simulation.status
|
|
error('Perfect foresight simulation failed')
|
|
end
|
|
|
|
% Initialize the analytical solution for the endogenous variables.
|
|
expected_y = zeros(1, 6);
|
|
expected_pi = zeros(1, 6);
|
|
expected_i = zeros(1, 6);
|
|
|
|
% Set period 2.
|
|
tmp = inv(eye(3)-[0 0 a1; a2 0 0; a5 a4 0])*[oo_.exo_simul(2); 0; 0];
|
|
|
|
if tmp(3)>=0
|
|
expected_y(2) = tmp(1);
|
|
expected_pi(2) = tmp(2);
|
|
expected_i(2) = tmp(3);
|
|
else
|
|
expected_y(2) = oo_.exo_simul(2);
|
|
expected_pi(2) = expected_y(2)*a2;
|
|
expected_i(2) = 0;
|
|
end
|
|
|
|
% Set period 1.
|
|
tmp = inv(eye(3)-[0 0 a1; a2 0 0; a5 a4 0])*[oo_.exo_simul(1)+expected_y(2)-a1*expected_pi(2); a3*expected_pi(2); 0];
|
|
|
|
if tmp(3)>=0
|
|
expected_y(1) = tmp(1);
|
|
expected_pi(1) = tmp(2);
|
|
expected_i(1) = tmp(3);
|
|
else
|
|
expected_y(1) = oo_.exo_simul(1)+expected_y(2)-a1*expected_pi(2);
|
|
expected_pi(1) = expected_y(2)*a2+a3*expected_pi(2);
|
|
expected_i(1) = 0;
|
|
end
|
|
|
|
% Compare the paths returned by sim1_purely_forward routine and the analytical solution.
|
|
if max(abs(oo_.endo_simul(1,:)-expected_y))>options_.dynatol.x || ...
|
|
max(abs(oo_.endo_simul(2,:)-expected_i))>options_.dynatol.x || ...
|
|
max(abs(oo_.endo_simul(3,:)-expected_pi))>options_.dynatol.x
|
|
error('Wrong solution!')
|
|
end
|