You can see in the pdf, N=3. For a lot of conclusions, there is nearly no evidence here.

That being said; money printing is an interesting economic tool in that it is an extreme stretch to say it has any positive impact in the real world. That the US is now resorting to it as a strategy for what seems to be every crisis is a very bad sign. Not because it is, in itself, a problem but because it suggests the leadership in several systemically important decision making offices are being challenged and are not capable of answering the challenge.