Dear team Dynare.
When I run my mod file, it indicates this error message:

The generalized Schur (QZ) decomposition failed. For more information, see the documentation for Lapack function dgges: info=30, n=21. You can also
run model_diagnostics to get more information on what may cause this problem.

and molde_diagnostics says it’s because of a colinear equations.

model_diagnostics(M_, options_, oo_);
MODEL_DIAGNOSTICS: The Jacobian of the static model is singular
MODEL_DIAGNOSTICS: there is 1 colinear relationships between the variables and the equations
Colinear variables:
epsilontheta
R
Omega
theta
epsilon
l
k
w
lr
lw
c
cr
cw
lambda
hr
hw
y
inv
a
Rk
pi
pistar
mc
g
b
tau
f1
f2
ii
Colinear equations
14 16 17 20
MODEL_DIAGNOSTICS: The presence of a singularity problem typically indicates that there is one
MODEL_DIAGNOSTICS: redundant equation entered in the model block, while another non-redundant equation
MODEL_DIAGNOSTICS: is missing. The problem often derives from Walras Law.

I’ve checked equations 14, 16, 17, 20, but I think these are still needed.

Could anyone please give me some advice to solve this issue?

Hello, professor, thank you very much for your reply!
I tried Dynare version 4.6.0, and 5.1. both indicated the similar error message.
version 5.1 says: The generalized Schur (QZ) decomposition failed. For more information, see the documentation for Lapack function dgges: info=30, n=21. You can also
run model_diagnostics to get more information on what may cause this problem.

version 4.6.0 says: One of the eigenvalues is close to 0/0 (the absolute value of numerator and denominator is smaller than 0.0000!
If you believe that the model has a unique solution you can try to reduce the value of qz_zero_threshold.

But the model diagnstics mentioned that there is 1 colinear relationships between the variables and the equations.

I’ve replicate Gertler 1999(Government debt and social security in a life-cycle economy) and It worked I think. (with the same parameter the paper mentioned)
So I silightly extended model which I add NK calvo price setting and fiscal and monetary policy.
and something happened here.

Professor, can you please tell me how I try different parameterizations? most of parameters are the same as Gertler’s paper. I have no idea what to do. Please.

This is a very hard problem to debug. It seems the error message differs across version due to numerical issues. In any case, I tend to believe it may be something systematic. But problems like the current one are very hard to debug. If you have a baseline version that runs without any indication of a problem, it’s most probably one of the modifications that causes the error.