In all instances, the Fed as central bank is buying promises to pay in the future, as bonds. There -should- be a limit on the total amount of such credit in our economies. The difference is, with private entity bonds, there is at least some drag on the total amount of such future credit. Credit as notes through the banking system is ultimately throttled, in some sense, by the finite amount of available credit that private entities have.

With public bonds, especially US Gov't bonds, there is apparently no upper bounds on the total amount of such future credit.

The number one willing holder of US Govt debt in the past used to be the SS Trust Fund; no matter how willing, that willing debt holder is newly out of the debt holding market. As Congress and the POTUS continue to magically raise the debt ceiling bound by nothing but their whims, the reality of finding brand new willing debt holders -- at such low rates of interest -- is slapping them up the side of the head. And so, they will on an accelerated basis do the only thing they can do: print US Bonds on a laser printer, sell them to the FED, and not only create money out of nothing, but pre-spend the wealth and toil and effort of endless people not even born yet.

Now, desperate, the US Govt must rely on the FED to buy its bonds.

Our Treasury can show up with a self-declared unlimited and endless credit demand, and flood our economies with current accounts manufactured from nothing. Not quite the same as simply printing money-- because in theory, those notes will be paid for in the future by demands placed on taxpayers. But that is a sham, because the future arrives, and the only thing that ever happens is a totally unbounded self-awarded increase in the ability to borrow more money, now, some to payoff old debt, and yet more, to freshly spend anew. To go out into the economies and, if properly connected to the selective political cronies, bathe in the sea of printed money and cushy contracts and demand value from the struggling economies.

We are watching the death spiral of US Government finances.

In the meanwhile, America is going to take all the time it can --- all the time it can endure -- to figure this one out. And it is exactly the middle class and poor who have and will continue to bear the brunt of this nonsense.