The double coincidence of wants refers to a situation in a barter economy where both trading parties simultaneously desire exactly what the other possesses, allowing for a direct exchange of goods or services.

• Example: If you have eggs and want bread, while the other party has bread and wants eggs, a mutually beneficial trade can take place.
• However, such perfect alignment of desires is rare, which makes barter inefficient as transactions require this precise matching of needs at the same time.