I am running some deterministic simulations in Dynare, and I would like to look at the effects of a change in parameters over time (for example, growth rates, demographics, and so on). However, due to the nature of my model, some steady state variables do not have a closed form expression, and as such I need to solve them numerically (with fsolve).

The question I have is: what is the best way to handle steady state computation for deterministic simulations? Should I go with providing a numerical guess (computed externally) using `initval;`

or with either `steady_state_model;`

or a `_steadystate.m`

file? How to handle this problem when deep parameters are changing over time, particularly when the fsolve routine requires these time-varying deep parameters as inputs?

For example:

`initval; a = a_initial; n = n_initial; end;`

`steady;`

where by _steadystate.m contains:

`options[...]; %solver options`

`ss_vars0 = [1,2,3]; %initial guesses`

`ss_vars = fsolve(@(x) find_steady(x,...,a,n,...),ss_vars0,options);`

`R = ss_vars(1);`

`Z = ss_vars(2);`

`W = ss_vars(3);`

`PI = 1;`

`Q = 1;`

`...`

and where I also need:

`endval; a=a_final, n=n_final; end;`

Such that I feed a smoothed fitted series of values for `a`

and `n`

to Dynare using the `shocks;`

block.

Has anyone got advice on this or an example mod file? Thanks.