(三)课后练习 tradeoffs.Use a production possibilities frontier to illustrate society's tradeoff betweena clean environment and high incomes.What do you suppose determines the shape and position of the frontier?Show what happens to the frontier if engineers develop an automobile engine with almost no emissions (四) 教学方法与手段 课堂讲授。 第三章Interdependence and The Gains from Trade (-) 目的与要求 By the end of this chapter,students should understand: 1.how everyone can benefit when people trade with one another 2.the meaning of absolute advantage and comparative advantage 3.how compar ative advantage explains the gains from trade 4.how to apply the theory of comparative advantage to every life and nation policy. (二) 教学内容 A Parable for the Modem Economy A. Example:two goods meat and potatoes and two people a cattle rancher and a potato farmer (both of whom like to consume both potatoes and meat). Production possibilities The Principle of Comparative Advantage A. Absolute Advantage Definition of Absolute Advantage:the comparison among producers of a good according to their productivity. Opportunity Cost and Comparative Advantage Definition of Opportunity Co:whatever must be given up toobain some item. Definition of Comparative Advantage:the comparison among producers of a good according to their opportunity cost. 3. Because the opportunity cost of producing one good is the inverse of the oppo the other,it is in possible fo person to have a comparative advantage in the production of both goods. Comparative Advantage and Trade When specialization in a good occurs (assuming there is a comparative advantage),total output will grow 66 （三） 课后练习 1. The first principle of economics discussed in Chapter 1 is that people face tradeoffs. Use a production possibilities frontier to illustrate society’s tradeoff between a clean environment and high incomes. What do you suppose determines the shape and position of the frontier? Show what happens to the frontier if engineers develop an automobile engine with almost no emissions. （四） 教学方法与手段 课堂讲授。 第三章 Interdependence and The Gains from Trade （一） 目的与要求 By the end of this chapter, students should understand: 1. how everyone can benefit when people trade with one another 2. the meaning of absolute advantage and comparative advantage 3. how comparative advantage explains the gains from trade 4. how to apply the theory of comparative advantage to every life and nation policy. （二） 教学内容 I. A Parable for the Modern Economy A. Example: two goods — meat and potatoes and two people — a cattle rancher and a potato farmer (both of whom like to consume both potatoes and meat). B. Production Possibilities C. Specialization and Trade II. The Principle of Comparative Advantage A. Absolute Advantage Definition of Absolute Advantage: the comparison among producers of a good according to their productivity. B. Opportunity Cost and Comparative Advantage 1. Definition of Opportunity Cost: whatever must be given up to obtain some item. 2. Definition of Comparative Advantage: the comparison among producers of a good according to their opportunity cost. 3. Because the opportunity cost of producing one good is the inverse of the opportunity cost of producing the other, it is impossible for a person to have a comparative advantage in the production of both goods. C. Comparative Advantage and Trade 1. When specialization in a good occurs (assuming there is a comparative advantage), total output will grow