There are centralbanks!When bonds can be outsorced to centralbanks it seems that they can do it over and over.
Important is that all great economic spaces do it in the same way.Which is the case in the moment.
Interest rate must be low.
For me it ssems that all great nations play this games.Nations like (russia) who don't want to play this game get sanctions.
What is a second factor is a low energy price.In this defintion range they can do it longer as we can imagine.