Final answer:
The economy where goods and services are exchanged without an expected or immediate return is known as a Gift Economy. This is different from a barter economy, which requires a double coincidence of wants, and is less efficient than a market economy that uses money.
Step-by-step explanation:
The name of the economy that consists of situations where goods and services are exchanged without an expected or immediate return is a Gift Economy. In a gift economy, items or services are given without any explicit agreement for immediate or future rewards. This contrasts with a barter economy, where there is a direct exchange of goods or services, and a market economy, which is driven by the forces of supply and demand and typically uses money as a medium of exchange.
In environments where money is not used, such as a barter economy, the exchange relies on the double coincidence of wants. This is where each party has something the other wants. However, managing such exchanges in a modern economy with countless goods and services can be highly complex and inefficient, hence the historical shift towards money as a common medium of exchange.