in the real world, there are often protests against opening to trade. This suggests that something must be missing or wrong in the assumptions of the model, so that some groups of people feel that they lose from opening to trade. Explain why U.S. workers employed in the phone sector gain in the Ricardian model, but that this conclusion might be less clear in a more realistic model of opening to trade. What do the workers in the phone sector do after the two countries open to trade? What are the costs and benefits of doing this in the model? In the 'real world'?