3. Suppose that, from an initial equilibrium position in the offer curve diagram, country I imposes a tariff on country II's export good at the same time that consumers in country II change their tastes toward wanting more of II's export good. Illustrate and explain the impact of these two simultaneous events on country I's volume and terms of trade. (Assume that both countries' offer curves are "elastic" throughout.)

4. Will the gains from trade be larger or smaller if one of the factors is not mobile in production? Why? Demonstrate your conclusion graphically. Is it true that if neither factor is mobile the country will receive no gains from trade? Explain.