Final answer:
Quota rent is the extra profit that producers make when supply is restricted by an import quota, due to the ability to charge higher prices in a less competitive market.
Step-by-step explanation:
The extra profit that producers make when supply is artificially limited by an import quota is referred to as a quota rent. This term describes the earnings above the normal profit level that producers obtain due to the restrictions on supply created by the quota.
When a country imposes an import quota, the supply of that particular good is reduced, which can lead to higher prices and, therefore, higher profits for domestic producers.
These extra profits, or rents, accrue because the restriction on imports allows domestic producers to charge more than they otherwise could in a more competitive market. Essentially, quota rents are a measure of the monetary benefit that accrues to producers due to the imposition of the quota.