the effect of a tariff in the small country case where a country cannot affect foreign export prices. in this case a tariff raises the price of the imported good in the country imposing the tariff by the full amount of the tariff, from Pw to Pw + t. production of the imported good rises from S1 to S2, while consumption of the good falls from D1 to D2. as a result of the tariff, then, imports fall in the country imposing the tariff.