Why does money have value?

A dollar bill is a piece of paper. It buys things not because of what it's printed on, but because everyone accepting it believes everyone after them will accept it too. That belief is what economists call trust, and it's the entire foundation of money.

This wasn't always paper backed by nothing but belief — gold and silver coins had value partly because the metal itself was scarce and useful. But even a gold coin only worked as money because people agreed to treat it as a stable unit of account, not just a lump of metal.

Different forms of money and value earn that trust in different ways — that's the whole idea behind DollarAndGold's five trust models. A dollar is trusted because of the institution behind it; gold because of its scarcity and history; Bitcoin because of a network and its rules.