It's not the wild west, though. The Central Bank do know how much these banks are issuing; and also differentiate between the different kinds of money. And not

It's not the wild west, though. The Central Bank do know how much these banks are issuing; and also differentiate between the different kinds of money. And not only banks issue money, other financial institutions do also issue some kind of money. From Wikipedia (https://en.wikipedia.org/wiki/Money_supply https://en.wikipedia.org/wiki/Money_supply) - M0: In some countries, such as the United Kingdom, M0 includes bank reserves, so M0 is referred to as the monetary base, or narrow money.[20] - MB: is referred to as the monetary base or total currency.[17] This is the base from which other forms of money (like checking deposits, listed below) are created and is traditionally the most liquid measure of the money supply.[21] - M1: Bank reserves are not included in M1. - M2: Represents M1 and "close substitutes" for M1.[22] M2 is a broader classification of money than M1. M2 is a key economic indicator used to forecast inflation.[23] - M3: M2 plus large and long-term deposits. Since 2006, M3 is no longer published by the US central bank.[24] However, there are still estimates produced by various private institutions. - MZM: Money with zero maturity. It measures the supply of financial assets redeemable at par on demand. Velocity of MZM is historically a relatively accurate predictor of inflation.[25][26][27] You can see the M0, M1 and M2 money supplies at Trading Economics: https://tradingeconomics.com/united-states/money-supply-m2 https://tradingeconomics.com/united-states/money-supply-m2 By the way, you can issue money too. Let's say you buy a computer for $1.000 and promise the seller that you are going to pay him $1.050 by next year. You just issued $1.050 of M2. Counter-intuitively, this money supply system is helping developed countries control inflation. In some developing countries, inflation is harder to control because people are issuing money on their own.