What a person desires to sell is exactly not the same as what other wishes to buy, in other words when both the parties( buyer & seller) do not agree to exchange each other’* goods is called as the problem of double coincidence of need.
The producer of wheat may want shoes in exchange he may find it difficult to get a person who is willing to take the wheat. No exchange is possible if the double co-incidence of wants is not there. Money solves this problem as producer of wheat can sell wheat & get money from which he can buy shoes. He does’nt need to find a person who is ready to sell shoes & ready to buy wheat.
