Chapter 5 개방경제 (The Open Economy) Chapter 5 extends the analysis to a small open economy. This PowerPoint presentation contains a slide explaining why the U.S. is often called “the world’s largest debtor nation.” This material will help motivate the rest of the chapter: First, students learn exactly what trade surpluses and trade deficits are. Next, students learn the link between the trade balance and net capital outflow or net lending to/borrowing from abroad. Finally, students see a new time series graph on the U.S. trade deficit, and get the latest available numbers on U.S. net indebtedness to the rest of the world. This data begs the question: how did it come to this? why has the U.S. had such huge trade deficits? what can the government do about this? These are among the many topical questions that students will better understand as they study this chapter. NOTE: If you are planning on covering chapter 12 (Aggregate Demand in the Open Economy), then covering this chapter is highly recommended.

이 장에서 공부할 내용 개방경제의 회계항등식 소국 개방경제 모형 “소국”을 구분하는 기준은 무엇인가? 무역수지와 환율은 어떻게 결정되나? 어떤 정책들이 무역수지와 환율에 영향을 미칠까?

세계 여러국가의 무역-GDP 비율, 2004 GDP에서 차지하는 (수입 + 수출) 비중 룩셈부르크 275.5% 아일랜드 150.9 체코 공화국 143.0 헝가리 134.5 오스트리아 97.1 스위스 85.1 스웨덴 83.8 대한민국 83.7 폴란드 80.0 캐나다 73.1 독일 71.1% 터키 63.6 멕시코 61.2 스페인 55.6 영국 53.8 프랑스 51.7 이탈리아 50.0 호주 39.6 미국 25.4 일본 24.4 This data shows the degree of “openness” (measured by the trade-to-GDP ratio) of selected OECD countries. Despite the huge absolute value of U.S. trade, most of the other countries shown have higher trade-GDP ratios. Source: OECD.org

개방경제에서는, 지출이 생산량과 일치할 필요가 없다. 저축이 투자와 일치할 필요가 없다. Regarding “spending need not equal output”: Residents of an open economy can spend more than the country’s output simply by importing foreign goods. Residents can spend less than output, and the extra output will be exported. Regarding “saving need not equal investment”: If individuals in an open economy want to save more than domestic firms want to borrow, no problem. The savers simply send their extra funds abroad to buy foreign assets. Similarly, if domestic firms want to borrow more than individuals are willing to save, then the firms simply borrow from abroad (i.e. sell bonds to foreigners).

예비단계(Preliminaries) 윗첨자들: d = 국내상품에 대한 소비 f = 해외상품에 대한 소비 EX = 수출 = 국내상품에 대한 해외 소비 IM = 수입 = C f + I f + G f = 해외상품에 대한 국내소비 NX = 순수출 ( “무역수지”라고도 함) = EX – IM Before displaying the second and subsequent lines, explain the first one: Total consumption expenditure is the sum of consumer spending on domestically produced goods and foreign produced goods. EX: The value of the goods we export to other countries equals their expenditure on our output. IM: The value of our imports equals the portion of our country’s expenditure (the portion of C+I+G) that falls on foreign products.

GDP = 국내에서 생산된 재화와 서비스에 대한 지출 A country’s GDP is total expenditure on its output of final goods & services. The first line adds up all sources of spending on domestically produced goods & services. The second & subsequent lines present an algebraic derivation of the national income accounting identity for an open economy.

개방경제하에서의 국민소득 항등식 (The national income identity in an open economy) Y = C + I + G + NX or, NX = Y – (C + I + G ) 산출량 순수출 국내지출 Solving this identity for NX yields the second equation, which says: A country’s net exports---its net outflow of goods---equals the difference between its output and its expenditure. Example: If we produce $500b worth of goods, and only buy $400b worth, then we export the remainder. Of course, NX can be a negative number, which would occur if our spending exceeds our income/output.

무역수지 흑자와 적자 (Trade surpluses and deficits) NX = EX – IM = Y – (C + I + G ) 무역흑자(trade surplus): 산출량 > 지출 및 수출 > 수입 무역흑자의 크기 = NX 무역적자(trade deficit): 지출 > 산출량 및 수입 > 수출 무역적자의 크기 = –NX

미국의 순수출 , 1950-2006 (U.S. net exports) After learning the terms trade surplus and trade deficit on the preceding slides, we see here that the U.S. has had trade deficits since the early 1980s. In the early 1990s, the trade deficit shrunk relative to GDP, but since then it’s become huge. The next slides show the link between the trade balance and capital flows. Students will see that the huge trade deficits on this slide have caused the U.S. to become the world’s largest debtor nation (and will learn exactly what that means). source: FRED Database, The Federal Reserve Bank of St. Louis, http://research.stlouisfed.org/fred2/

국제적 자본이동 (International capital flows) 순자본유출(Net capital outflow) = S – I = 대부자금”의 순유출 = 해외자산의 순구매 해외자산의 국내구매에서 국내자산의 해외구매를 차 감한 값 S > I 일 때, 이 국가는 순대부자(net lender)이다. S < I 일 때, 이 국가는 순차입자(net borrower)이다 In chapter 3, we examined a closed economy model of the loanable funds market. Savers could only lend money to domestic borrowers. Firms borrowing to finance their investment could only borrow from domestic savers. Thus, S = I. But in an open economy, S need not equal I. A country’s supply of loanable funds can be used to finance domestic investment, or to finance foreign investment (e.g. buying bonds from a foreign company that needs funding to build a new factory in its country). Similarly, domestic firms can finance their investment projects by borrowing loanable funds from domestic savers or by borrowing them from foreign savers. International borrowing and lending is called “international capital flows” even though it’s not the physical capital that is flowing abroad --- we don’t see factories uprooted and shipped to Mexico (Ross Perot’s famous remark notwithstanding). Rather, what can flow internationally is “loanable funds,” or financial capital, which of course is used to finance the purchase of physical capital. Note: foreign investment might involve the purchase of financial assets – stocks and bonds and so forth – or physical assets, such as direct ownership in office buildings or factories. In either case, a person in one country ends up owning part of the capital stock of another country. The equation “net capital outflow = S – I” shows that, if a country’s savers supply more funds than its firms wish to borrow for investment, the excess of loanable funds will flow abroad in the form of net capital outflow (the purchase of foreign assets). Alternatively, if firms wish to borrow more than domestic savers wish to lend, then the firms borrow the excess on international financial markets; in this case, there’s a net inflow of loanable funds, and S < I.

무역수지와 자본흐름의 연관성 (The link between trade & cap. Flows) NX = Y – (C + I + G ) 이므로 NX = (Y – C – G ) – I = S – I 무역수지 = 순자본유출 Starting from the equation derived on slides 6 and 7, we can derive another important identity: NX = S – I This equation says that Net exports (the net outflow of goods) = net capital outflow (the net outflow of loanable funds) While the identity and its derivation are very simple, we learn a very important lesson from it: A country (such as the U.S.) with persistent, large trade deficits (NX < 0) also has low saving, relative to its investment, and is a net borrower of assets. 따라서, 무역적자(NX < 0)인 국가는 순차입자가 된다(S < I ).

세계에서 가장 채무가 큰 국가 (“The world’s largest debtor nation”) 미국은 1980년대 이래로 매해 순차입자였으며, 가장 큰 무역적자국이다. 2005년 12월 31일 현재: 미국인들은 10.0조 달러의 해외자산을 보유하고 있다. 외국인들은 12.7조 달러의 미국자산을 보유하고 있다. 미국이 다른 나라에 지고 있는 순채무: 2.7조 달러로서 다른 어느 나라보다도 많다. 따라서 미국은 세계에서 가장 큰 채무국(“world’s largest debtor nation”)이 다. Source: Bureau of Economic Analysis, http://www.bea.gov Look for “International Investment Position” under “International” or “International Economic Accounts” The U.S.’ net indebtedness to the rest of the world (henceforth NIROW) is $2.7 trillion as of the end of 2005. The U.S. NIROW is bigger than any other country’s NIROW, which is why the U.S. has earned the dubious distinction of being “the world’s largest debtor nation.” Servicing this huge debt, of course, uses up some of our GDP each year (though fortunately relatively little). How did it get to this point? Why do we have such huge trade deficits year after year? How do government policies affect the trade deficit? These are the questions your students will learn about in the rest of this chapter.

소국 개방경제에서의 저축과 투자 (Saving and investment in a small open economy) 3장에서 배운 대부자금모형을 개방경제에 적용시킬 수 있다. 동일한 요소들이 많다: 생산함수 소비함수 투자함수 외생적 정책변수

총저축: 대부자금의 공급 (National saving: The supply of loanable funds) r S, I 3장에서와 마찬가지로 총저축은 이자율에 의존하지 않는다.

가정: 자본이동 (Assumptions: Capital flows) a. 국내채권과 해외채권은 완전 대체재이다(위험, 만기 등이 동일하다). b. 완전한 자본이동성(perfect capital mobility): 자산의 국가간 이동에 아무런 제약이 없다. c. 경제규모는 작다(small): 세계 이자율(r* )에 영향을 미치지 못한다 This slide is the first on which students see a foreign variable, in this case, the foreign interest rate r*. In general, a star or asterisk “*” on a variable denotes the foreign or world version of that variable. Thus, Y* = foreign GDP, P* = foreign price level, etc. The assumption that domestic & foreign bonds are perfect substitutes is implicit in the text, but necessary for the equality of the domestic and foreign interest rate. Students will realize that assumption a is unrealistic, and c is unrealistic for the U.S. (as well as Japan and the Euro zone). However, these assumptions keep our model simple, and we can still learn a LOT about how the world works (just as the model of supply and demand in perfectly competitive markets is often not realistic, yet teaches us a great deal about how the world works). At the end of the chapter, there’s a brief section discussing how the results we are about to derive differ in a large open economy. And you may wish to have your students read the appendix to chapter 5, which presents a formal model of the large open economy. a & b 는 r = r*을 의미한다. c 는 r* 이 외생적임을 의미한다.

투자: 대부자금의 수요 (Investment: The demand for loanable funds) 투자는 여전히 이자율에 대하여 우하향의 기울기를 가진 함수이다. r S, I I (r ) 그러나 외생적인 세계 이자율은….. r * …그 나라의 투자수준을 결정한다. I (r* )

만일 경제가 폐쇄적이라면 (If the economy were closed…) S, I I (r ) …이자율은 투자와 저축을 일치시키도록 조정될 것이다: rc

그러나 소국 개방경제에서는 (But in a small open economy…) r S, I 외생적인 세계 이자율이 투자수준을 결정하고… I (r ) NX r* I 1 …저축과 투자의 차이는 순자본유출과 순수출을 결정한다. rc This graph really determines net capital outflow, not NX. But, the national accounting identities say that NX = net capital outflow, so we write “NX” on the graph as shown. A little bit later in the chapter, we will see that it is the adjustment of the exchange rate that ensures that NX = net capital outflow. For now, though, students will just have to trust the accounting identities.

세 가지 실험: (three experiments) 1. 국내의 재정정책 2. 해외의 재정정책 3. 투자수요의 증가 In the textbook, NX = 0 in the economy’s initial equilibrium for each of these three experiments. In these slides, NX > 0 in the initial equilibrium. For completeness, you might have your students repeat the three experiments for the case of NX < 0 in the initial equilibrium. This would be a good homework or in-class exercise.

국내의 재정정책 (Fiscal policy at home) r S, I G의 증가 혹은 T의 감소는 저축을 감소시킨다. I (r ) NX2 I 1 NX1 결과: In a small open economy, the fixed world interest rate pins down the value of investment, regardless of fiscal policy changes. Thus, a $1 decrease in saving causes a $1 decrease in NX and net capital outflow. Note that the analysis on this slide applies to ANYTHING that causes a decrease in saving. Other examples: a shift in consumer preferences regarding the tradeoff between saving and consumption, or a change in the tax laws that reduces the incentive to save. Our model generates a prediction: the government’s budget deficit and the country’s trade balance should be negatively related. Does this prediction come true in the real world? Let’s look at the data….

소국개방경제하에서 국내의 재정팽창 [그림 5-3] r * 실질이자율, r S2 S1 I(r) 투자, 저축, I, S 2. 재정팽창으로 인해 저축이 감소 1. 무역수지가 균형인 상태에서 출발 r * Page.140 NX 3. 무역수지 적자 발생 I(r) 투자, 저축, I, S

순수출과 연방재정적자, 1960-2006 (NX and the federal budget deficit) (% of GDP), 4% 8% 재정적자 (오른쪽 축) 6% 2% 4% 0% 2% -2% 0% Our model implies a negative relationship between NX and the budget deficit. We observe this negative relationship during most periods. Exceptions: 1. Late 1970s. 2. 1991-2001. In the latter period, the U.S. enjoyed an unusually long expansion, which fueled a surge in both imports and tax revenues. Source: Department of Commerce. Obtained from: http://research.stlouisfed.org/fred2/ 순수출 (왼쪽 축) -4% -2% -6% -4% 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 slide 21

해외의 재정정책 (Fiscal policy abroad) S, I I (r ) 해외에서의 확장적인 재정정책은 세계 이자율을 상승시킨다. NX2 NX1 결과: It might be worth taking a moment to explain that the world interest rate r* is determined by saving and investment in the world loanable funds market. S* is the sum of all countries’ saving; I* the sum of all countries’ investment. r* adjusts to equate I* with S*, just like in Chapter 3, because the world as a whole is a closed economy. A fiscal expansion in other countries would reduce S* and raise r* (same results as in chapter 3). The higher world interest rate reduces investment in our small open economy, and hence reduces the demand for loanable funds. The supply of loanable funds (national saving) is unchanged, so there’s an increase in the amount of funds flowing abroad.

소국개방경제하에서 해외의 재정팽창 [그림 5-4] r * r * 실질이자율, r S I(r) 투자, 저축, I, S 2. 투자의 감소와 무역흑자의 발생 NX 1. 세계 이자율의 상승 r * 2 Page.141 r * 1 I(r) 투자, 저축, I, S

3. 투자수요의 증가 (An increase in investment demand) S, I S I (r )1 I 1 NX1 예제: 모형을 사용하여 투자수요의 증가가 NX, S, I, 및 순자본흐름에 어떤 영향을 미치는지 살펴보아라. Have students get out a piece of paper, draw this graph on it, and then do the analysis. A couple minutes should suffice. It might be useful to have them compare their answers with the results from the closed economy case.

3. 투자수요의 증가 (An increase in investment demand) S, I S I (r )2 NX2 풀이: I > 0, S = 0, 순자본흐름과 순수출(NX)은 투자증가분(I ) 만큼 하락한다. I (r )1 I 1 NX1 I 2 In contrast to a closed economy, investment is not constrained by the fixed (domestic) supply of loanable funds. Hence, the increase in firm’s demand for loanable funds can be satisfied by borrowing abroad, which reduces net outflow of financial capital. And since net capital outflow = NX, we see a fall in NX equal to the increase in investment.

소국개방경제하에서 투자스케줄의 이동 [그림 5-5] 실질이자율, r S r* I(r)2 I(r)1 투자, 저축 I, S 1. 투자수요의 증대 2. 무역적자의 발생 NX r* Page.142 I(r)2 I(r)1 투자, 저축 I, S

명목환율 (The nominal exchange rate) (예; 1 달러당 엔화 환율, Yen/$) Warning to students: Some textbooks and newspapers define the exchange rate as the reciprocal of the one here (e.g., dollars per yen instead of yen per dollar). The one here is easier to use, because a rise in “e” corresponds to an “appreciation” of the country’s currency. Using the reciprocal would mean that a rise in “e” is a depreciation, which seems counter-intuitive. So it would be worthwhile to point out to students that a country’s “e” is simply the price (measured in foreign currency) of a unit of that country’s currency.

환율, 2006년 7월 14일 현재 국가 환율 유로 0.79 Euro/$ 인도네시아 9,105 Rupiahs/$ 일본 116.3 Yen/$ 멕시코 11.0 Pesos/$ 러시아 27.0 Rubles/$ 남아프리카 7.2 Rand/$ 영국 0.54 Pounds/$ If you’d like to update these figures before your lecture, you can find good exchange rate data at: http://www.xe.net/ict/

실질환율 (The real exchange rate) = 실질환율, 외국상품의 크기로 표시한 국내상품의 상대가격 (예; 미국 빅맥 1개 당 일본 빅맥의 양) ε 그리스어 소문자 엡실론 epsilon

[그림 5-7] 순수출과 실질환율 실질환율, Page.150 NX( ) 순수출, NX

제5장 개방경제

[그림 5-8] 실질환율의 결정 실질환율, S - I 균형실질 환율 Page.151 NX( ) 순수출, NX

실질환율의 이해 (Understanding the units of ε) Students often have trouble understanding the units of the real exchange rate. It’s worth explaining each line carefully, and making sure students understand it before displaying the next line. Note: The examples here and in the text are in terms of one good, i.e. Big Macs. But P and P* are the overall price levels of the domestic & foreign countries. Thus, they each measure the price of a basket of goods. When you get to the bottom line, emphasize that the real exchange rate measures the amount of purchasing power in Japan that must be sacrificed for each unit of purchasing power in the U.S.

~ McZample ~ ε 1가지 재화: Big Mac 일본에서의 가격: P* = 200 Yen 명목환율 e = 120 Yen/$ 미국 빅맥 1개를 사기 위해서는, 일본 빅맥 1.5개를 살 만큼의 엔화가 필요하다. ε slide 35

현실세계 및 모형에서의 실질환율 (ε in the real world & our model) 현실세계에는: 실질환율(ε)을 외국상품 바스켓으로 표시한 국 내상품 바스켓의 상대가격으로 생각할 수 있다. 우리의 거시모형에서는: 오직 1가지 재화(“산출물”)만 존재하므로 실질 환율(ε)을 타국의 산출물로 표시한 한 국가의 산출물의 상대가격이다. A good candidate for the basket of goods mentioned here is the CPI basket. Perhaps a better candidate would be a basket including all goods & services that comprise GDP. Then, the real exchange rate would measure how many units of foreign GDP trade for one unit of domestic GDP.

순수출은 실질환율에 어떻게 영향을 받을까? (How NX depends on ε ) ε  외국상품에 비해서 상대적으로 미국상품이 더 비 싸진다.  EX, IM  NX

미국의 순수출과 실질환율 , 1973-2006 (U.S. net exports and the real exchange rate) 3% 무역가중 실질환율지수 140 2% 120 1% 100 0% -1% (대 GDP 비중) (1973년 3월 = 100) 80 -2% 60 -3% NX The real exchange rate here is a broad index. Source: Federal Reserve Statistical Release H.10, Board of Governors. (To find it, simply google “Federal Reserve Statistical Release H.10”) NX as a percent of GDP was computed from NX and GDP source data from Department of Commerce, Bureau of Economic Analysis, obtained at: http://research.stlouisfed.org/fred2/ -4% 순수출 (왼쪽 축) 40 지수 -5% 20 -6% -7% 1973 1977 1981 1985 1989 1993 1997 2001 2005

순수출함수 (The net exports function) 순수출함수(The net exports function) 순수출(NX)과 실질환율(ε) 사이의 역관계를 반영한 것이다: NX = NX(ε )

미국의 순수출 곡선 (The NX curve for the U.S.) NX ε NX (ε) NX(ε1) 따라서 미국의 순수출은 높을 것이다 ε1 ε 가 상대적으로 낮을 때, 미국상품은 상대적으로 비싸다

미국의 순수출 곡선 (The NX curve for the U.S.) ε2 실질환율(ε)이 충분히 높은 값을 가지고 있을 때 미국상품은 매우 비싸지므로 NX ε NX (ε) NX(ε2) 수입보다 수출이 작아진다

실질환율은 어떻게 결정될까? (How ε is determined) 회계항등식에 의하면 NX = S – I 우리는 이미 어떻게 S – I 가 결정되는지 살펴보았다: S 는 국내 요소(산출량, 재정정책 변수 등) I 는 세계이자율(r *)에 의하여 결정된다. 따라서, ε 는 다음 식을 만족시킬 수 있도록 조정되어야 한다. In the equation, ε is the only endogenous variable, hence this equation determines the value of ε.

실질환율은 어떻게 결정될까? (How ε is determined) S 와 I 모두 ε에 의존하지 않으므로 순자본흐름 곡선은 수직이다. ε NX NX(ε ) ε 는 NX 가 순자본유출(S - I)과 일치되게끔 조정된다. ε 1 *** Note *** At the lower left corner (origin) of this graph, NX does NOT NECESSARILY EQUAL ZERO!!! NX 1

해석: 외환시장에서의 수요와 공급 (Supply and demand in the foreign exchange market) ε NX 수요: 외국인들은 미국의 순수출품을 구입하기 위하여 달러를 필요로 한다. NX(ε ) 공급: 순자본유출 (S - I )은 해외로 투자될 달러의 공급이다. ε 1 WARNING: Don’t let your students confuse the demand for dollars in the foreign exchange market with demand for real money balances (chapter 4), or the supply of dollars in the foreign exchange market with the supply of money (chapter 4). If you and your students are into details: NX is actually the net demand for dollars: foreign demand for dollars to purchase our exports minus our supply of dollars to purchase imports. Net capital outflow is the net supply of dollars: The supply of dollars from U.S. residents investing abroad minus the demand for dollars from foreigners buying U.S. assets. NX 1

경제정책은 실질환율에 어떤 영향을 미치는가 -4가지 실험(Next, four experiments) 1. 국내의 재정정책 2. 해외의 재정정책 3. 투자수요의 증가 4. 수입제한 무역정책

국내에서의 재정정책 (Fiscal policy at home) NX 2 ε 2 재정확대는 외환시장에서의 총저축, 순자본유출, 및 통화공급을 감소시킨다… ε NX NX(ε ) ε 1 NX 1 …이는 실질환율의 상승과 순수출(NX)의 감소를 초래한다.

국내의 팽창적 재정정책이 실질환율에 미치는 영향 [그림 5-9] 국내의 팽창적 재정정책이 실질환율에 미치는 영향 실질환율, S2 - I S1 - I 1. 저축의 감소는 달러의 공급을 감소시킨다. 2 2. 실질 환율을 상승 시킨다. 1 Page.140 NX( ) NX2 NX1 순수출, NX 3. 순수출을 감소시킨다.

해외에서의 재정정책 (Fiscal policy abroad) ε NX NX(ε ) NX 1 ε 1 ε 2 NX 2 …이는 실질환율을 떨어뜨리고 순수출(NX)을 감소시킨다.

해외의 팽창적 재정정책이 실질환율에 미치는 영향 [그림 5-10] 해외의 팽창적 재정정책이 실질환율에 미치는 영향 실질환율, S – I(r*) S – I(r*) 1 2 1. 세계이자율의 상승은 투자를 감소 시키며 이는 달러의 공급을 증가시킨다. 2 1 2. 실질환율 을 하락 시킨다. Page.153 NX( ) NX1 NX2 순수출, NX 3. 순수출을 증대시킨다.

투자수요의 증가 (Increase in investment demand) NX 2 ε 2 투자의 증가는 외환시장에서 순자본유출과 통화공급을 감소시킨다… ε NX NX 1 NX(ε ) ε 1 … 이는 실질환율의 상승과 순수출(NX)의 감소를 초래한다. Suggestion: Have your students do this experiment as an in-class exercise. Have them take out a piece of paper, draw the graph, then show what happens when there’s an increase in the country’s investment demand (perhaps in response to an investment tax credit).

제5장 개방경제

투자수요의 증대가 실질환율에 미치는 영향 [그림 5-11] NX2 NX1 실질환율, S – I 2 S – I 1 NX( ) 1. 투자의 증가는 달러의 공급을 감소시킨다. 2 2. 환율을 상승 시킨다. 1 Page.153 NX( ) NX2 NX1 순수출, NX 3. 순수출을 감소시킨다.

수입제한 무역정책 (Trade policy to restrict imports) ε이 주어져 있을 때, 수입쿼터  IM  NX  달러수요곡선의 우측이동 ε NX NX (ε )1 NX1 ε 1 NX (ε )2 ε 2 무역정책은 S나 I 에 영향을 미치지 않으므로 자본흐름과 통화공급에는 아무런 변화가 없다. The analysis here applies for import restrictions (tariffs, quotas) as well as export subsidies. It also applies for exogenous changes in preferences regarding domestic vs. foreign goods.

4. 수입제한 무역정책 (Trade policy to restrict imports) 결과: ε > 0 (수요 증가) NX = 0 (공급 일정) IM < 0 (정책) EX < 0 (ε 상승) ε NX NX1 NX (ε )2 NX (ε )1 ε 2 ε 1 In the text box, the remarks in parentheses after each result are an abbreviated explanation for that result. The real exchange rate appreciates because the quota has raised the net demand for dollars associated with any given value of the exchange rate. But the equilibrium level of net exports doesn’t change, because the supply of dollars in the foreign exchange market (S-I) has not been affected by the trade policy. (Remember, S = Y-C-G, and the trade policy does not affect Y, C, or G; the policy also does not affect I, because I = I(r*) and r* is exogenous.) The appreciation causes exports to fall. And, since exports are lower but NX is unchanged, it must be the case that IM is lower too, which is what you’d expect from a trade policy that restricts imports.

명목환율의 결정요인 (The determinants of the nominal exchange rate) 실질환율에 관한 식은: 명목환율에 대하여 풀면:

1. 보호무역주의자의 정책은 수수출에 대한 수요를 증대시킨다. [그림 5-12] 보호무역주의자의 무역정책이 실질환율에 미치는 영향 실질환율, S - I 1. 보호무역주의자의 정책은 수수출에 대한 수요를 증대시킨다. 2 2. 환율을 상승 시킨다. Page.154 1 NX( )2 NX( )1 순수출, NX NX1 = NX2 3. 순수출은 불변이다.

명목환율의 결정요인 (The determinants of the nominal exchange rate) …그리고 우리는 이것들이 어떻게 결정되는지 알고 있다: It’s important here for students to learn the (logical, not necessarily chronological) order in which the variables are determined. I.e., what causes what.

명목환율의 결정요인 (The determinants of the nominal exchange rate) 이 식을 성장률로 고쳐쓰면 (백분율 변화에 관한 수학적 기법에 대해서는 2장을 참조할 것 ) Here we again see the Classical Dichotomy in action. The real exchange rate is determined by real factors, and nominal variables only affect nominal variables. Suppose the U.S. is the home country and Mexico is the foreign (starred) country, and suppose that Mexico’s inflation rate (pi*) is higher than that of the U.S. This equation implies: the greater is Mexico’s inflation relative to the U.S., the faster the dollar should rise relative to the peso. The next slide presents cross-country data consistent with this implication. 실질환율(ε)이 주어져 있을 때, 명목환율(e)의 성장률은 해외와 국내 인플레이션율의 차이와 같다.

인플레이션 격차와 명목환율 (Inflation differentials and nominal exchange rates) 멕시코 아이스랜드 싱가포르 남아프리카 캐나다 Figure 5-13 on p.141. The horizontal axis measures the country’s inflation rate minus the U.S. inflation rate. The vertical axis measures the percentage change in the U.S. dollar exchange rate with that country. All variables are annual averages over the period 1972-2004. This figure shows a very clear relationship between the inflation differential and the rate of dollar appreciation. The higher a country’s inflation relative to U.S. inflation, the faster the U.S. dollar will appreciate against that country’s currency. Or, for the few countries like Japan that have lower inflation than the U.S., we see the U.S. exchange rate depreciating relative to those countries’ currencies. Source: International Financial Statistics 한국 영국 일본

구매력 평가 (Purchasing Power Parity, PPP) 두 가지 정의: 상품들은 모든 나라에서 동일한 가격으로 판매되어야 한 다는 주장 명목환율은 국가들 간에 상품 바스켓의 구입비용이 일치 되도록 조정 이유: 차익거래, 일물일가의 법칙

구매력 평가 (Purchasing Power Parity, PPP) PPP: e P = P* 외화로 표시된 해외상품 바스켓의 구입비용 외화로 표시된 국내상품 바스켓의 구입비용 국내화폐로 표시된 국내상품 바스켓의 구입비용 e에 대하여 풀면: e = P*/ P PPP는 두 국가 간의 명목환율이 이들 국가의 물가수준 비율(즉 상대물가수준)과 동일하다는 것을 의미한다. PPP implies that the cost of a basket of goods (even a basket with just one good, like a Big Mac or a latte) should be the same across countries. e P = the foreign-currency cost of a basket of goods in the U.S., while P* the cost of a basket of foreign goods. PPP implies that the baskets cost the same in both countries: eP = P*, which implies that e = P*/P.

구매력 평가 (Purchasing Power Parity, PPP) 만일 e = P*/P 라 면 그리고 NX 곡선은 수직이므로: ε NX ε = 1 S - I PPP 하에서, (S – I )의 변화는 ε나 e에 아무런 영향을 미치지 못한다 Revisiting our model, PPP implies that the NX curve should be horizontal at  = 1. Intuition for the horizontal NX curve: Under PPP, different countries’ goods are perfect substitutes, and international arbitrage is possible. If the relative price of U.S. goods falls even a tiny bit below 1, then there’s a profit opportunity: buy U.S. goods and sell them abroad. Hence, the tiniest drop in the U.S. real exchange rate causes a massive increase in NX. Similarly, if the relative price of U.S. goods rises even a tiny amount above 1, then it is profitable to buy foreign goods and sell them in the U.S., so this arbitrage causes a massive increase increase in imports---and decrease in NX. Thus, under PPP, the real exchange rate equals 1 regardless of net capital outflow S-I. Changes in S or I have no impact on the real exchange rate.

현실 세계에서 PPP는 타당한가? (Does PPP hold in the real world?) 다음 두 가지 이유로 타당하지 않다: 1. 국제적으로 차익거래가 가능하지 않다. 비교역재(nontraded goods) 운송비(transportation costs) 2. 국가들 간에 상품들이 완전대체재가 아니다. 그럼에도 불구하고, PPP는 유용한 이론이다: 간단하고 직관적이다. 현실 세계에서, 명목환율은 장기적으로 PPP의 값에 접근하는 경향이 있다.

사례연구: 레이건 재정적자의 재고찰 (The Reagan deficits revisited) 폐쇄경제 소국개방경제 실제변동 ε NX I r S G – T 1980년대 1970년대 115.1 -0.3 19.9 1.1 19.6 2.2 129.4 -2.0 19.4 6.3 17.4 3.9   변동 없음     변동 없음 This is a continuation of the case study begun in Chapter 3 (both the textbook and the PowerPoint presentation). It is placed here to motivate the last topic of Chapter 5: the U.S. as a large open economy. As we saw in chapter 3, the closed economy model correctly predicted that national saving would fall and the interest rate would rise. But, the closed economy model predicted that investment would fall as much as saving; actually, investment fell by much less than saving. Also, the closed economy model by definition could not have predicted the effects on the trade balance or exchange rate. The small open economy model correctly predicted what would happen to NX and the real exchange rate, but incorrectly predicted that the interest rate and investment would not change. In order to explain the U.S. experience, we need to combine the insights of the closed & small open economy models. 데이타: 10년 평균; r과 ε를 제외한 모든 값들은 GDP에 대한 비중으로 표시됨; ε는 무역가중지수임.

대국 개방경제로서의 미국 (The U.S. as a large open economy) 지금까지는, 두 가지 극단적인 경우의 장기모형을 살펴보았다: 폐쇄경제 (3장) 소국개방경제 (5장) 미국과 같은 대국개방경제는 이 두 가지 극단적인 경우의 중간적인 형태에 해당한다. 대국개방경제에 대한 분석결과는 폐쇄 및 소국 개방경제의 결과들이 혼재되어 나타난다. 예를 들면…

세 가지 모형에서의 재정확대 효과 (A fiscal expansion in three models) 재정확대에 따른 총저축의 감소가 미치는 영향은 개방여부와 경제규모의 대소에 따라 다르다: NX I r 대국 개방 경제 소국 개방 경제 폐쇄 경제 상승 폐쇄경제보다 적게 상승 변동 없음 감소 폐쇄경제보다 적게 감소 변동 없음 In the table, there’s a cell for NX in the closed economy column. Instead of putting “N.A.” in this cell, I put “no change.” Why? In a closed economy, EX = IM = NX = 0. After a change in saving, NX = 0 still. Hence, it is not incorrect to say “no change”. More importantly we are trying to show students how the results for a large open economy are in between the results for the closed & small open cases. Looking at the items in the last row of the table, “falls, but not as much as in small open economy” seems to be in between “no change” and “falls,” but does not seem to be in between “N.A.” and “falls”. It would be completely understandable if you still feel that “N.A.” should be in the closed economy NX cell of the table, so please feel free to edit that cell. 변동 없음 소국개방경제보다 적게 감소 감소

요약 순수출은 다음의 차이를 말한다. 순자본유출은 다음과 같다. 수출과 수입 일국의 총산출(Y )과 총지출(C + I + G) 해외자산의 구매액 - 국내자산의 해외구매액 저축과 투자의 차이 slide 67

요약 국민소득 회계항등식: 경제정책이 NX 에 미치는 효과: Y = C + I + G + NX 무역수지균형 NX = S - I 순자본유출 경제정책이 NX 에 미치는 효과: 정책이 S를 증가시키거나 I를 감소시킨다면 NX는 증가한다. 정책이 S와 I 모두에 영향을 미치지 않는다면 NX는 변하지 않는다. 예: 무역정책 slide 68

요약 환율 명목환율: 일국 화폐의 가격을 타국 화폐의 크기로 표시한 것 명목환율: 일국 화폐의 가격을 타국 화폐의 크기로 표시한 것 실질환율: 일국 상품의 가격을 타국 상품의 크기로 표시한 것 실질환율은 명목환율과 두 국가간의 상대물가 수준을 곱한 값과 같다. slide 69

요약 실질환율은 어떻게 결정되나? NX는 다른 모든 조건이 일정할 때 실질환율의 움직임에 반대방향으로 영향을 미친다. slide 70

요약 명목환율은 어떻게 결정되나? 명목환율은 실질환율과 외국의 물가수준에 대한 일국의 상대물가수준을 곱한 값과 같다. 명목환율은 실질환율과 외국의 물가수준에 대한 일국의 상대물가수준을 곱한 값과 같다. 실질환율이 주어져 있을 때, 명목환율의 변화율은 외국과 국내의 인플레이션율의 차이와 같다. slide 71