A pound in your bank account is no more than a promise by the bank to pay you that pound; you don’t actually own any publicly created money. In fact, commercial banks create new money (in the sense of money in bank accounts) whenever they make loans, and that money disappears when the loan is paid back. The fact that the size of our money supply – the total amount of money in circulation – is dependent upon millions of separate commercial lending decisions by banks makes it hard to maintain economic stability.
for keynesian demand management and demand side economic policies