>Surely the banks have to declare how much cash they're holding. Couldn't they just be forced to pay negative interest on that? Could they? With appropriate le

>Surely the banks have to declare how much cash they're holding. Couldn't they just be forced to pay negative interest on that? Could they? With appropriate legislation/government action, of course. >..or give the money to someone else for a while so they can do something with it. You are talking about forcing them to invest the money. And what happens if that person cannot pay back what was lent to them? If there were any available investments that were safe enough, the banks would be tripping over each other to make that investment, believe me. Hoarding money costs the bank money. Investing it is not only free, but it turns their money into more money. If you were to force them to make unsafe investments, then that risk is essentially passed onto the people who deposited their money in that bank, in the form of potentially not being able to withdraw their money.