I recently updated from dynare 4.5.7 to 5.4. In the simple Ramsey growth model I’m analyzing most things remain the same, but I’m puzzled by one difference. With 4.5.7 I got
EIGENVALUES:
Modulus Real Imaginary
0.949 0.949 0
1.106 1.106 0
There are 1 eigenvalue(s) larger than 1 in modulus
for 1 forward-looking variable(s)
while with 5.4 I get (for the same model specification)
EIGENVALUES:
Modulus Real Imaginary
0.949 0.949 0
1.106 1.106 0
Inf -Inf 0
There are 2 eigenvalue(s) larger than 1 in modulus
for 2 forward-looking variable(s)
It seems to me there’s only one “real” forward-looking variable, namely c, so I’m wondering where the extra infinite eigenvalue is coming from. The model spec is as follows
model;
// Resource constraint
y - A*x*k(-1)^alpha;
c + k - y - (1-delta)*k(-1);
s - (y-c)/y;
// Euler equation
c^(-sigma) - (1+theta)^(-1)*(A*alpha*x(+1)*k^(alpha-1) + 1 - delta)*c(+1)^(-sigma);
end;
Thanks for any enlightenment.