Final answer:
Consumer surplus decreases and producer surplus increases with the introduction of a tariff.
Step-by-step explanation:
When a tariff is introduced, the consumer surplus changes from a higher amount to a lower amount. This is because consumers now have to pay a higher price for a lower quantity of goods, reducing their surplus.
On the other hand, the producer surplus changes from a lower amount to a higher amount. Producers are now able to sell more quantity at a higher price, resulting in an increase in their surplus.