3.2. On Bills of Exchanges and their Nature
There is an expense associated with transporting money based on the distance, risks, and other transaction costs. Bills of Exchange are a type of contract that can reduce this cost by avoiding shipments that are offsetting between two locations. When money must be sent, bankers charge a fee for arranging the shipment and providing their customers with a bill of exchange, or check, that can be drawn or cashed at a correspondent bank where the money is sent. When the exchange rate is above par, it indicates a balance of payments deficit, and when the exchange rate is below par, it indicates a balance of payments surplus.
From Part 3: International Trade and Business Cycles. Narrated by Millian Quinteros.