I am trying to look for ramsey optimal policy in Gali Chapter 8 nonlinear model in Dynare 4.6.4, which this code comes from Prof. Pfeifer. But something is wrong, code is attached below:
I have read most the ramsey policy posts on the dynare forum . I have two question:
(1) In the state-state-model or _steadystate.m ，Do we not need to set the initial value of the instrument variable？
But, as we can see, If the instrument variable does not have an initial value ，the steady-state value of other variables represented by it may be NAN .
(2) The code run successfully in taylor rule, if we put it in ramsey optimal policy, Do we still need to change the equation in _steadystate.m ?
(3)If we introduce uncertainty shocks into the model, can we still make ramsey optimal monetary policy ?
Thank you so much in advance!