Answer:
Principle of a double coincidence of wants.
Step-by-step explanation:
The principle of a double coincidence of desires is the basis of an exchange economy. It occurs when two parties wish to exchange an item they each own without the exchange being made involving any monetary payment, so both parties need to be willing to agree to sell and buy each commodity. This economic phenomenon arises due to needs, desires or motivational situations for the exchange to take place in the same place and time.