Interdependence and the Gains from Trade 상호의존관계와 교역의 이득

Presentation on theme: "Interdependence and the Gains from Trade 상호의존관계와 교역의 이득"— Presentation transcript:

1 Interdependence and the Gains from Trade 상호의존관계와 교역의 이득
3 Interdependence and the Gains from Trade 상호의존관계와 교역의 이득 Economics P R I N C I P L E S O F N. Gregory Mankiw Please ask your students in advance to bring calculators to class. This PowerPoint chapter includes simple in-class exercises which lead students to see for themselves the gains from trade arising from comparative advantage. This PowerPoint chapter covers the same topics as Chapter 3 in the textbook (comparative & absolute advantage, the gains from trade), but using a different example and a different approach that is likely to benefit your students. The textbook presents these topics using an example involving two individual producers (the farmer & rancher). After the example, the textbook states that its lessons apply to countries as well as individual producers. This PowerPoint presentation takes the opposite approach, illustrating the concepts with an example involving two countries, and then states that that the lessons apply to individuals as well as countries. Seeing the analysis both ways, and seeing a different example in class than in the textbook, will help students better learn these concepts. The example in this PowerPoint chapter builds on the PPF example introduced in the Chapter 2 PowerPoint. (It is not essential to cover the Chapter 2 PowerPoint before this one, though.) This PowerPoint omits “Should Tiger Woods Mow His Own Lawn?” It’s a great example of comparative advantage, but it does not introduce any new concepts, and students can easily understand it on their own. Premium PowerPoint Slides by Ron Cronovich

2 In this chapter, look for the answers to these questions:
사람들은 (그리고 국가들은) 왜 경제적으로 서로 의존하는 것을 선택하는가? Why do people – and nations – choose to be economically interdependent? 교역은 어떻게 모두를 더 잘살게 해주는가? How can trade make everyone better off? 절대우위란 무엇인가? What is absolute advantage? 비교우위란 무엇인가? What is comparative advantage? 이 개념들은 어떻게 비슷한가? How are these concepts similar? 그것들은 어떻게 다른가? How are they different? 1

3 상호의존관계 Interdependence
매일 여러분은 전세계 수많은 사람들에게 의존하고 있다. 대부분 한 번도 만난 적이 없는 그들은 여러분이 즐기는 재화와 서비스를 제공해주고 있다. Every day you rely on many people from around the world, most of whom you’ve never met, to provide you with the goods and services you enjoy. hair gel from Cleveland, OH cell phone from Taiwan dress shirt from China coffee from Kenya 2

4 상호의존관계 Interdependence
제1장의 10대 기본원리 중 하나는 교역이 모든 사람들을 더 잘살게 해 준다는 것이다. One of the Ten Principles from Chapter 1: Trade can make everyone better off. 사람들이 (그리고 국가들이) 왜 서로 의존하는 것을 선택하고 어떻게 교역으로부터 이득을 얻는지 학습하자. We now learn why people – and nations – choose to be interdependent, and how they can gain from trade. INTERDEPENDENCE AND THE GAINS FROM TRADE

5 Our Example 미국과 일본 두 나라 Two countries: the U.S. and Japan
미국과 일본 두 나라 Two countries: the U.S. and Japan 컴퓨터와 밀 두 재화 Two goods: computers and wheat 자원은 노동 한 가지로 시간으로 측정 One resource: labor, measured in hours 우리는 (다음 경우에) 각국이 두 재화를 얼마나 많이 생산하고 소비하는지를 살펴볼 것이다 We will look at how much of both goods each country produces and consumes 자급자족을 선택한다면 if the country chooses to be self-sufficient 다른 나라와 교역을 한다면 if it trades with the other country The lessons illustrated by this international trade example also apply to trade between two individual producers. Note that this chapter in the textbook does the reverse: It develops the lessons in the context of an example involving two individual producers, and then states that the lessons also apply to international trade. So, between this PowerPoint and the textbook chapter, students will see the same concepts and lessons developed in two different but entirely consistent approaches and examples. The example here is highly contrived and unrealistic in order to illustrate complex concepts as simply as possible. The example has some qualities that make it especially valuable: * The two goods are fundamentally different (one is agricultural, the other manufactured), which makes gains from trade based on comparative advantage very likely. An example using more similar goods, say laptop computers and MP3 players, would not be appropriate for this chapter because it would more likely give rise to inter-industry trade, and the gains would likely arise from a source other than comparative advantage (probably increasing returns to scale). * In the example here, it turns out that the U.S. has an absolute advantage in both goods, yet both countries gain from trade. Students see, therefore, that comparative advantage, not absolute advantage, is what’s necessary for trade to be mutually beneficial. * In the real world, one often sees gains from trade based on comparative advantage occurring between countries that are very different – such as between rich industrialized countries and poor developing countries. This example shows that trade based on comparative advantage can also occur between countries that are at similar levels of industrialization and income. (Of course, the U.S. and Japan are very different; but they are far more similar than are, say, the U.S. and Botswana.) INTERDEPENDENCE AND THE GAINS FROM TRADE 4

6 미국의 생산가능성 Production Possibilities in the U.S.
미국은 한 달에 5만 시간의 노동을 생산에 쓸 수 있다. The U.S. has 50,000 hours of labor available for production, per month. 컴퓨터 1대를 생산하는 데 100시간의 노동이 필요하다. Producing one computer requires 100 hours of labor. 밀 1톤을 생산하는 데 10시간의 노동이 필요하다. Producing one ton of wheat requires 10 hours of labor. If you just covered Chapter 2, point out to your students that the U.S. PPF here is the same as in the Chapter 2 PowerPoint. Warn students that, in a few moments, they will be asked to derive Japan’s PPF. They will need to follow the same steps that you are about to show for deriving the U.S. PPF. INTERDEPENDENCE AND THE GAINS FROM TRADE 5

7 미국의 생산가능곡선 The U.S. PPF 4,000 100 5,000 2,000 1,000 3,000 500 200 300 400 Computers Wheat (tons) 미국은 컴퓨터 500대를 생산하기에 충분한 노동을 가지고 있다. The U.S. has enough labor to produce 500 computers, 혹은 밀 5,000톤이나 PPF 상 어떤 조합도 생산할 수 있다. or 5,000 tons of wheat, or any combination along the PPF. Deriving the intercepts, or endpoints of the PPF: The U.S. has 50,000 labor hours. It takes 100 hours to produce a computer. If the U.S. uses all its labor to produce computers, then it will produce 50,000/100 = 500 computers. Hence, the horizontal intercept is (500 computers, 0 wheat). It takes 10 hours to produce a ton of wheat. If the U.S. uses all its labor to produce wheat, then it will produce 50,000/10 = 5000 tons of wheat. Hence, the vertical intercept is (0 computers, 5000 tons of wheat). The PPF is the straight line that connects the two endpoints. INTERDEPENDENCE AND THE GAINS FROM TRADE 6

8 무역을 안 할 때의 미국 The U.S. Without Trade
4,000 100 5,000 2,000 1,000 3,000 500 200 300 400 Computers Wheat (tons) 미국이 노동력의 절반씩을 각 재화의 생산에 사용한다고 하자. Suppose the U.S. uses half its labor to produce each of the two goods. 그러면 컴퓨터 250대와 밀 2,500톤을 생산하여 소비할 것이다. Then it will produce and consume 250 computers and 2,500 tons of wheat. Of course, the U.S. could choose a different point. The actual choice will depend on the preferences of society. (In the following chapter – on supply and demand – we will learn what determines how much of each good society produces.) Important note for students: Without trade, a country consumes what it produces. INTERDEPENDENCE AND THE GAINS FROM TRADE 7

9 A C T I V E L E A R N I N G 1 일본의 생산가능곡선을 도출하라 Derive Japan’s PPF
다음 정보를 이용하여 일본의 생산가능곡선을 그려라. Use the following information to draw Japan’s PPF. 일본은 한 달에 3만 시간의 노동을 생산에 쓸 수 있다. Japan has 30,000 hours of labor available for production, per month. 컴퓨터 1대를 생산하는 데 125시간의 노동이 필요하다. Producing one computer requires 125 hours of labor. 밀 1톤을 생산하는 데 25시간의 노동이 필요하다. Producing one ton of wheat requires 25 hours of labor. (Your graph should measure computers on the horizontal axis.) Using this information to draw Japan’s PPF requires a calculator (or the ability to do long division). If your students have the “gutted handout” of these slides, they can draw their PPF on the axes provided on the following slide. This activity should take only 3 minutes of class time. It’s good practice & review for students, and helps break up the lecture. 8

10 일본의 생산가능곡선 Japan’s PPF Computers Wheat (tons) 2,000 1,000 200 100 300 Japan has enough labor to produce 240 computers, or 1,200 tons of wheat, or any combination along the PPF. Horizontal intercept: (30,000 labor-hours)/(125 hours per computer) = 240 computers. Vertical intercept: (30,000 labor-hours)/(25 hours per ton of wheat) = 1200 tons of wheat. INTERDEPENDENCE AND THE GAINS FROM TRADE 9

11 무역을 안 할 때의 일본 Japan Without Trade
Computers Wheat (tons) 2,000 1,000 200 100 300 일본이 노동력의 절반씩을 각 재화에 사용한다고 하자. Suppose Japan uses half its labor to produce each good. 그러면 120대의 컴퓨터와 600톤의 밀을 생산하여 소비할 것이다. Then it will produce and consume 120 computers and 600 tons of wheat. INTERDEPENDENCE AND THE GAINS FROM TRADE 10

12 소비 Consumption With and Without Trade
무역을 안 할 때 Without trade, 미국 소비자는 컴퓨터 250대와 밀 2,500톤을 얻는다 U.S. consumers get 250 computers and 2,500 tons wheat. 일본 소비자는 컴퓨터 120대와 밀 600톤을 얻는다 Japanese consumers get 120 computers and 600 tons wheat. 무역을 안 할 때와 무역을 할 때 소비를 비교할 것이다. We will compare consumption without trade to consumption with trade. 먼저, 두 나라가 각 재화를 얼마나 생산하여 교역하는지 살펴볼 필요가 있다. First, we need to see how much of each good is produced and traded by the two countries. INTERDEPENDENCE AND THE GAINS FROM TRADE 11

13 A C T I V E L E A R N I N G 2 무역을 할 때의 생산 Production under trade
1. 미국이 3,400톤의 밀을 생산한다고 하자. 남은 노동으로 미국은 몇 대의 컴퓨터를 생산할 수 있는가? 미국의 생산가능곡선 상에 이 조합을 나타내는 점을 그려라. Suppose the U.S. produces 3,400 tons of wheat. How many computers would the U.S. be able to produce with its remaining labor? Draw the point representing this combination of computers and wheat on the U.S. PPF. 2. 일본이 240대의 컴퓨터를 생산한다고 하자. 남은 노동으로 일본은 몇 톤의 밀을 생산할 수 있는가? 일본의 생산가능곡선 상에 이 점을 그려라. Suppose Japan produces 240 computers. How many tons of wheat would Japan be able to produce with its remaining labor? Draw this point on Japan’s PPF. Give your students a few minutes to solve these problems before showing the answers on the next slides. This will break up the lecture, get the students involved, and give them practice with “word problems.” It is not necessary that all students finish both problems before moving on. It’s fine if most finish the first, and a few finish the second. However, the second problem is easy for most students. Note that most students will need a calculator to solve the first problem. 12

14 무역을 할 때 미국의 생산 U.S. Production With Trade
Computers Wheat (tons) 4,000 100 5,000 2,000 1,000 3,000 500 200 300 400 3,400톤의 밀을 생산하는 데 34,000시간의 노동이 필요하다. Producing 3,400 tons of wheat requires 34,000 labor hours. 남은 16,000시간의 노동력은 160대의 컴퓨터를 생산하는 데 사용된다. The remaining 16,000 labor hours are used to produce 160 computers. Point out to students that the red dot represents the combination (160 computers, 3400 tons of wheat). We will assume that this is the combination the U.S. produces in the scenario in which the U.S. trades. INTERDEPENDENCE AND THE GAINS FROM TRADE 13

15 무역을 할 때 일본의 생산 Japan’s Production With Trade
Computers Wheat (tons) 2,000 1,000 200 100 300 240대의 컴퓨터를 생산에는 일본의 3만 시간 노동 전부가 필요하다. Producing 240 computers requires all of Japan’s 30,000 labor hours. 따라서 일본의 밀 생산은 0이 될 것이다. So, Japan would produce 0 tons of wheat. The red dot represents the combination (240 computers, 0 tons wheat). We will assume this is the combination that Japan produces. Point out that, just because Japan is not producing any wheat does not mean that Japan’s consumers must all go on the Atkins diet (which shuns bread and other foods made from wheat). When trade is allowed, Japan can trade some of its computers for wheat produced in another country. INTERDEPENDENCE AND THE GAINS FROM TRADE 14

16 기본적 무역 용어 Basic international trade terms
Exports: goods produced domestically and sold abroad To export means to sell domestically produced goods abroad. Imports: goods produced abroad and sold domestically To import means to purchase goods produced in other countries. These terms are so basic that many instructors skip this slide. There’s a subtle point that you might want to mention (if you’re anal like me), or that your students might ask about (especially if tourism is an important part of your local economy). Someone from Germany or South Korea visits Las Vegas and spends $200 on a pair of tickets to a show. How should we classify this and other expenditures by foreign tourists on lodging and entertainment while they are vacationing here? Answer: we count it in U.S. exports. It doesn’t matter that the service was consumed here. What matters is that it was produced here but sold to a foreign buyer. Hence, a more precise definition of exports would be goods and serviced produced here and purchased by foreign buyers. This stricter definition of exports doesn’t care whether the good or service was consumed in the buyer’s home country or in the exporting country. Similarly, a stricter and more precise definition of imports would include purchases by domestic residents of goods and services produced abroad – including entertainment and lodging services that tourists from the U.S. consume in the foreign countries they visit. INTERDEPENDENCE AND THE GAINS FROM TRADE 15

17 A C T I V E L E A R N I N G 3 무역을 할 때의 소비 Consumption under trade
미국이 700톤의 밀을 일본으로 수출하고 110대의 컴퓨터를 일본으로부터 수입한다고 하자. Suppose the U.S. exports 700 tons of wheat to Japan, and imports 110 computers from Japan. (So, Japan imports 700 tons wheat and exports 110 computers.) 미국에서는 각 재화가 얼마나 소비되는가? 이 조합을 미국의 생산가능곡선에 표시하라. How much of each good is consumed in the U.S.? Plot this combination on the U.S. PPF. 일본에서는 각 재화가 얼마나 소비되는가? 이 조합을 일본의 생산가능곡선에 표시하라. How much of each good is consumed in Japan? Plot this combination on Japan’s PPF. Some students need help figuring out that consumption of a good is the difference between the amount produced and the amount exported. 16

18 무역을 할 때 미국의 소비 U.S. Consumption With Trade
Computers Wheat (tons) wheat computers 3400 160 produced 4,000 100 5,000 2,000 1,000 3,000 500 200 300 400 110 + imported 700 – exported 2700 270 = amount consumed The red point again represents production. Trade un-tethers consumption from production. The light blue point represents consumption. Notice that the consumption point is above the PPF. Without trade, it would not be possible to consume this combination of the two goods! In a sense, international trade is like technological progress: it allows society to produce quantities of goods that would otherwise not be possible. INTERDEPENDENCE AND THE GAINS FROM TRADE 17

19 무역을 할 때 일본의 소비 Japan’s Consumption With Trade
wheat computers Computers Wheat (tons) 2,000 1,000 200 100 300 240 produced 700 + imported 110 – exported 700 130 = amount consumed Again, the light blue point representing consumption is above the PPF. Without trade, it would not be possible to consume this combination of the goods. INTERDEPENDENCE AND THE GAINS FROM TRADE 18

20 무역을 하면 두 나라 모두 잘살게 된다 Trade Makes Both Countries Better Off
U.S. consumption without trade consumption with trade gains from trade 20 270 250 computers 200 2,700 2,500 wheat gains from trade consumption with trade consumption without trade Japan These tables summarize the gains from trade for both countries. 10 130 120 computers 100 700 600 wheat INTERDEPENDENCE AND THE GAINS FROM TRADE 19

21 이런 이득은 어디서 오는 것인가? Where Do These Gains Come From?
절대우위 Absolute advantage : 다른 생산자보다 적은 생산요소를 사용하여 재화를 생산하는 능력 the ability to produce a good using fewer inputs than another producer 미국은 밀에 절대우위가 있으니, 밀 1톤을 생산하는 데 일본이 25시간의 노동을 사용하는 반면 미국은 10시간을 사용한다 The U.S. has an absolute advantage in wheat: producing a ton of wheat uses 10 labor hours in the U.S. vs. 25 in Japan. 만약 각국이 한 재화에 절대우위를 가져서 그 재화에 특화한다면 양국은 모두 무역의 이득을 얻을 수 있다 If each country has an absolute advantage in one good and specializes in that good, then both countries can gain from trade. The last bullet point states that gains from trade will arise if each country has an absolute advantage in something. We will see next, though, that absolute advantage is not required for both countries to gain from trade. INTERDEPENDENCE AND THE GAINS FROM TRADE 20

22 이런 이득은 어디서 오는 것인가? Where Do These Gains Come From?
어느 나라가 컴퓨터에 절대우위를 가지는가? Which country has an absolute advantage in computers? 컴퓨터 1대에 필요한 노동이 Producing one computer requires 일본은 125시간 125 labor hours in Japan, 반면 미국은 단 100시간 but only 100 in the U.S. 미국은 두 재화 모두에 절대우위를 가진다. The U.S. has an absolute advantage in both goods! 그렇다면 왜 일본은 컴퓨터에 특화하고 왜 두 나라 다 무역의 이득을 얻는가? So why does Japan specialize in computers? Why do both countries gain from trade? INTERDEPENDENCE AND THE GAINS FROM TRADE 21

23 재화 비용의 두 가지 측정치 Two Measures of the Cost of a Good
두 나라가 각각 가장 낮은 비용으로 생산하는 재화에 특화를 하면 무역의 이득을 얻을 수 있다. Two countries can gain from trade when each specializes in the good it produces at lowest cost. 절대우위는 한 재화의 비용을 생산에 필요한 투입요소로 측정한다. Absolute advantage measures the cost of a good in terms of the inputs required to produce it. 다른 하나의 비용 측정치가 ‘기회비용’임을 상기하라 Recall: Another measure of cost is opportunity cost. 우리의 예에서 컴퓨터의 기회비용은 컴퓨터 1대 생산에 필요한 노동을 사용하여 생산할 수 있는 밀의 수량이다. In our example, the opportunity cost of a computer is the amount of wheat that could be produced using the labor needed to produce one computer. INTERDEPENDENCE AND THE GAINS FROM TRADE 22

24 기회비용과 비교우위 Opportunity Cost and Comparative Advantage
비교우위 Comparative advantage: 다른 생산자보다 더 낮은 기회비용으로 어떤 재화를 생산할 수 있는 능력 the ability to produce a good at a lower opportunity cost than another producer 어느 나라가 컴퓨터에 비교우위를 가지는가? Which country has the comparative advantage in computers? 이 질문에 답하려면 각국에서 컴퓨터의 기회비용을 판정해야 한다. To answer this, must determine the opp. cost of a computer in each country. INTERDEPENDENCE AND THE GAINS FROM TRADE 23

25 기회비용과 비교우위 Opportunity Cost and Comparative Advantage
컴퓨터 1대의 기회비용은 The opp. cost of a computer is 미국에서는 밀 10톤이다. 왜냐하면 컴퓨터 1대를 생산하는 데 필요한 100시간의 노동으로 밀 10톤을 생산할 수 있기 때문이다. 10 tons of wheat in the U.S., because producing one computer requires 100 labor hours, which instead could produce 10 tons of wheat. 일본에서는 밀 5톤이다. 왜냐하면 컴퓨터 1대를 생산하는 데 필요한 125시간의 노동으로 밀 5톤을 생산할 수 있기 때문이다. 5 tons of wheat in Japan, because producing one computer requires 125 labor hours, which instead could produce 5 tons of wheat. 그러므로 일본은 컴퓨터에 비교우위를 가진다. 비교우위를 위해 절대우위가 필수적인 것은 아니라는 교훈을 얻을 수 있다! So, Japan has a comparative advantage in computers. Lesson: Absolute advantage is not necessary for comparative advantage! INTERDEPENDENCE AND THE GAINS FROM TRADE 24

26 비교우위와 무역 Comparative Advantage and Trade
무역의 이득은 비교우위(기회비용의 차이)에서 발생한다 Gains from trade arise from comparative advantage (differences in opportunity costs). 각국이 비교우위가 있는 재화에 특화를 하면 모든 나라 생산의 합이 더 많아져 세계의 ‘경제적 파이’가 커지고 모든 나라는 무역의 이득을 얻을 수 있다. When each country specializes in the good(s) in which it has a comparative advantage, total production in all countries is higher, the world’s “economic pie” is bigger, and all countries can gain from trade. 똑같은 원리가 서로 다른 재화에 특화를 하여 서로 교역을 하는 개별 생산자(농부와 목장주인처럼)에게도 적용된다. The same applies to individual producers (like the farmer and the rancher) specializing in different goods and trading with each other. INTERDEPENDENCE AND THE GAINS FROM TRADE 25

27 A C T I V E L E A R N I N G 4 Absolute & comparative advantage
Argentina and Brazil each have 10,000 hours of labor per month. In Argentina, producing one pound coffee requires 2 hours producing one bottle wine requires 4 hours In Brazil, producing one pound coffee requires 1 hour producing one bottle wine requires 5 hours Which country has an absolute advantage in the production of coffee? Which country has a comparative advantage in the production of wine? Allow a few minutes for students to work on this problem. Ask for volunteers to share their answers. Variation: Before asking for volunteers, instruct students to compare their answers with their neighbors. Not everyone will volunteer to explain their answer to the class, but everyone will at least get to explain his or her answer to a classmate. 26

28 A C T I V E L E A R N I N G 4 Answers
Brazil has an absolute advantage in coffee: Producing a pound of coffee requires only one labor-hour in Brazil, but two in Argentina. Argentina has a comparative advantage in wine: Argentina’s opp. cost of wine is two pounds of coffee, because the four labor-hours required to produce a bottle of wine could instead produce two pounds of coffee. Brazil’s opp. cost of wine is five pounds of coffee. 27

29 남은 문제들 Unanswered Questions….
우리는 각국이 생산, 무역, 소비를 하는 각 재화의 수량 및 두 나라가 컴퓨터와 밀을 교환하는 가격에 관한 많은 가정을 하였다. We made a lot of assumptions about the quantities of each good that each country produces, trades, and consumes, and the price at which the countries trade wheat for computers. 현실 세계에서는 이 수량과 가격이 양국의 소비자 선호, 기술 및 자원에 의해 결정될 것이다. In the real world, these quantities and prices would be determined by the preferences of consumers and the technology and resources in both countries. (맨큐의 경제학) 다음 장에서부터 우리는 이것을 공부할 것이다. We will begin to study this in the next chapter. 다만 지금의 목표는 무역이 어떻게 모두를 더 잘살게 하는지를 보여주는 것뿐이다. For now, though, our goal was merely to see how trade can make everyone better off. The 5th edition adds a brief explanation of the range of prices that will permit gains from trade, in the context of the farmer-rancher example. The second bullet point mentions technology and resources. In our example, the technology is how many labor-hours are required to produce each good. The resources are simply the quantity of labor-hours available in each country. In the following chapter (on supply & demand), students will begin their study of how prices and quantities are determined. INTERDEPENDENCE AND THE GAINS FROM TRADE 28

30 CHAPTER SUMMARY Interdependence and trade allow everyone to enjoy a greater quantity and variety of goods & services. Comparative advantage means being able to produce a good at a lower opportunity cost. Absolute advantage means being able to produce a good with fewer inputs. When people – or countries – specialize in the goods in which they have a comparative advantage, the economic “pie” grows and trade can make everyone better off. 29