Ramsey policy :MJDGGES returns the following error code: 685


When trying to solve for the ramsey policy using the command:

“ramsey_policy(irf=30,planner_discount = 0.9928, order=1) c;”

(Here, c is a variable in the model)

I get the error message

“MJDGGES returns the following error code: 685”

Does anyone know what this means and what causes it?



This means that the QZ step for solving the linear rational expectation problem that is the linearization of the Ramsey problem failed.

I have seen it happen when the recursive definition of welfare is included in the model (the constraints of Ramsey problem) or the recursive definition of another value that is the current value of a future stream.