I tried with the initval and endval blocks:

[code]initval;

C =1.05961;

R =1.0101;

pibar =1;

F =3.8835;

K =3.8835;

s =0.833333;

pstar =1;

l =1.07497;

x =0.1;

Q =0.296039;

J =0.142857;

V =98.805;

U =98.7892;

mm =0.99;

f =3.30469;

vartheta =1;

tight =11.163;

Y =1.07497;

v =0.337793;

wbar =0.984429;

u =0;

taun =0;

irpef =0;

eps_taun =0;

//R_ann=4*R;

end;

steady(solve_algo=4, maxit=1000);

endval;

C =1.05961;

R =1.0101;

pibar =1;

F =3.8835;

K =3.8835;

s =0.833333;

pstar =1;

l =1.07497;

x =0.1;

Q =0.296039;

J =0.142857;

V =98.805;

U =98.7892;

mm =0.99;

f =3.30469;

vartheta =1;

tight =11.163;

Y =1.07497;

v =0.337793;

wbar =0.984429;

u =0;

taun =0;

irpef =0;

eps_taun = .1;

//R_ann=4*R;

end;

steady(solve_algo=4, maxit=1000);

shocks;

var eps_ut;

periods 1:9;

values 0;

end;

perfect_foresight_setup(periods=50);

perfect_foresight_solver(lmmcp);

figure

subplot(2,2,1)

plot(0:12,oo_.endo_simul(strmatch(‘C’,M_.endo_names,‘exact’),M_.maximum_lag+1:M_.maximum_lag+13),’-x’)

axis([0 12 -15 5])

subplot(2,2,2)

plot(0:12,oo_.endo_simul(strmatch(‘pibar’,M_.endo_names,‘exact’),M_.maximum_lag+1:M_.maximum_lag+13),’-x’)

axis([0 12 -25 5])

subplot(2,2,3)

plot(0:12,oo_.endo_simul(strmatch(‘R’,M_.endo_names,‘exact’),M_.maximum_lag+1:M_.maximum_lag+13),’-x’)

axis([0 12 -2 6])

subplot(2,2,4)

plot(0:12,oo_.endo_simul(strmatch(‘taun’,M_.endo_names,‘exact’),M_.maximum_lag+1:M_.maximum_lag+13),’-’)

axis([0 12 -6 6])[/code]

With small shocks, perfect foresight works, with stronger ones, homotopy does. However, the IRFs’ plots always appear flat, as if no change happened at all