Irf is wired in the first periods?

I made a fiscal policy shock,but the irf is wired in the first periods. I don’t know why?
The irf is attached.

Any help would be appreciated!
Thanks a million!

Generally speaking, using inappropriate values of parameters. It is hard to tell you where the problem is without the codes.

What is it that you consider to be weird? And why does your model feature such a high persistence after 20 periods?

I mean ,there shouldn’t be turning point, like the irf below


BSR.mod (9.7 KB) BSRindex.m (3.1 KB)
Thanks for your reply, here is my code.

There is no reason why an IRF cannot have a sharp turning point. It very much depends on the parameterization and the endogenous propagation mechanisms you put into the model. If you want to find out where it comes from, you need to simplify your by taking away features. At some point, the kink must go away.

Thank you , I guess I get the point. I change the parameters and it disappear .