> I don’t agree that it doesn’t make sense. It’s a good approximation a lot of the time.

So is a weather forecast that says “the weather will be sunny tomorrow” in Miami. True most of the time yet utterly meaningless.

> Also: from your comment I’m pretty sure you don’t have the background (correct me if that’s wrong)

I have to admit my DSGE class was more than 10 years ago at this point, but I still vividly remember the hypothesis being hilarious (spherical cow in vacuum−level) even though now I would need to spend a bit of time digging into it to be able to write down why exactly.