If you understood what money is you would not ask that question.
Do You ask what is gold backed by?
The banker JP Morgan famously answered that gold is money and nothing else.
Today bitcoin is added to the list of things that are money
Do not allow yourself to be defrauded by present day bankers. They wish to
present the credits and debits they find in their T-accounts as money.
They talk about "the money supply" when they mean "the debt supply"
Some ninety-seven percent of the "money" in circulation is no more than
an obligation on someone to extinguish a debt to someone else. The
remaining three percent is money - gold, silver, bitcoin. Everything else is no
more relevant than the position of beads on an abacus.
Unfortunately, perception matters. To understand this look at this image:
http://dragon.uml.edu/psych/woman.htmlThink of money as the young woman, and debt as the old woman.
They look the same but you cannot see money and debt at the same time.
When you hold money, you hold a scarce resource. When you hold debt
you are enslaved.