Use of filename_dynamic

Dynare help (legacy posts)
1

Dear all,

I am writing a mod file in which I declare the equations in log-levels, ie, exp(x) = …, where x is the log of my variable (say X).
When I use the stoch_simul command, I know Dynare computes a linear approximation around the steady-state of my model, so it is actually a log-linear approximation, given the way I declared my variables.

But I also want to use information of the model’s Jacobian which is stored in the modname_dynamic function. My question is, are these the jacobian associated with the variables in log-levels or in log deviation from the steady-state? Or does this make no difference at all?

Cheers.

2

Dynare always only knows the variables themselves when it takes analytical derivatives. It does not care about how you define them. The filename_dynamic and filename_static files store the derivatives of the model equations with respect to the model variables (declared with var).
If your model defines y to be the log-level of output, the Jacobian will thus be with respect to the log level of output.