Fiat currency already means the supply side of capital is detached from anything in reality. Remember price is where supply and demand meet, and interest rate is the price of capital. Central planning of the currency market, just like DDR had central planning of the car market with the Trabant.

With central banking, the supply can be infinite, and that’s what we Swedes are seeing with NEGATIVE interest rates. Jyske Bank in DK borrows to consumers house loans where you are paid to borrow. It can not end well, please someone show me logically/from first principle how it ever can.

The central actor can use the exact same rules that they currently make the lenders use.