Discuss allowed use of endogenous variables outside of model-block
Consider the mod-file
var y, c, k, a, h, b;
varexo e, u;
parameters beta, rho, alpha, delta, theta, psi, tau test;
alpha = 0.36;
rho = 0.95;
tau = 0.025;
beta = 0.99;
delta = 0.025;
psi = 0;
theta = 2.95;
phi = 0.1;
test=y*beta;
model;
c*theta*h^(1+psi)=(1-alpha)*y;
k = beta*(((exp(b)*c)/(exp(b(+1))*c(+1)))
*(exp(b(+1))*alpha*y(+1)+(1-delta)*k));
y = exp(a)*(k(-1)^alpha)*(h^(1-alpha));
k = exp(b)*(y-c)+(1-delta)*k(-1);
a = rho*a(-1)+tau*b(-1) + e;
b = tau*a(-1)+rho*b(-1) + u;
end;
initval;
y = 1.08068253095672;
c = 0.80359242014163;
h = 0.29175631001732;
k = 11.08360443260358;
a = 0;
b = 0;
e = 0;
u = 0;
end;
shocks;
var e; stderr 0.009;
var u; stderr 0.009;
var e, u = phi*0.009*0.009;
end;
stoch_simul;
The definition
test=y*beta;
results in the preprocessor plugging in for the endogenous variable y
with its yet uncomputed steady state, i.e. 0. Users thus can create a circular problem with the steady state of y
depending on test
with test
depending on y
- and would never notice the problem, because the definition does not result in an error. Would it be possible to block this behavior? If we want to allow users to access the steady state value of endogenous variables outside of the model-block, it should be through the steady_state
operator.
Or do I miss something that makes this behavior desirable?