Permanent shock

I’m trying to simulate a permanent shock (a permanent change in one of the model parameters). How should I do that?
I tried to use “histval” however the results are highly depended on the number of periods I use. What does it mean?
Many thanks

Hi there,

Correct me if I’m wrong, I am not really an expert.

In my model (no stochastics) I simply specified that the shock happens in period 1 and last until period 50 or something. Normally a model reaches the steady state after 10-20 periods. Copy the relevant outcomes (not all the way up to period 50 ofcourse) from Matlab to Excell or any other similar program.

//var s; periods 1:90; values 0.5952012;