A tariff always increases domestic consumer surplus while decreasing domestic producer surplus, regardless of the market conditions.

A tariff is a tax imposed on imported goods, and it can change how consumers and producers in a country behave. When a tariff is applied, the price of imported goods usually rises, which may lead domestic consumers to pay more or buy less. This situation can decrease consumer surplus because consumers are now paying higher prices or are unable to find the products they want at lower prices. On the other hand, domestic producers might benefit from less competition, which could increase their profits and producer surplus. However, the overall effect is that while domestic producers may gain, the losses for consumers often outweigh these gains, leading to a net decrease in overall welfare.