A world without money would require what economists call a double coincidence of:

1. Barter has a famous problem. 2. To understand the usefulness of money we consider a world without it. 3. That world is described under barter and the double coincidence of wants. 4. Each trader must want exactly what the other is offering. _Source: OpenStax Principles of Macroeconomics for AP Courses 2e (CC BY 4.0), Ch 13 'Money and Banking'_