多恩布什宏观经济学课后习题答案
多恩布什《宏观经济学》课后习题详解(政策预览)【圣才出品】
第9章政策预览一、概念题1．联邦公开市场委员会（FOMC）答：联邦公开市场委员会是联邦储备系统中一个重要的机构。
它由十二名成员组成，包括：联邦储备委员会全部成员七名，纽约联邦储备银行行长，其它四个名额由另外11个联邦储备银行行长轮流担任。
该委员会设一名主席（通常由联邦储备委员会主席担任），一名副主席（通常由纽约联邦储备银行行长担任），另外，其它所有的联邦储备银行行长都可以参加联邦公开市场委员会的讨论会议，但是没有投票权。
联邦公开市场委员会的最主要工作是利用公开市场操作（主要的货币政策之一），从一定程度上影响市场上货币的存量。
另外，它还负责决定货币总量的增长范围（即新投入市场的货币数量），并对联邦储备银行在外汇市场上的活动进行指导。
2．货币政策规则（monetary policy rule）答：货币政策规则是指基础货币和利率等货币政策工具如何根据经济行为的变化而进行调整的一般要求。
货币政策规则是相对于货币政策操作中相机抉择而言的。
执行货币政策规则的基本原因在于，随意性会导致政策在时间上前后不能一贯以至互相矛盾，进而影响货币政策的效果。
规则型政策的核心是，在方法上遵循计划，不是随机地或偶然地采取行动，而是具有连续性和系统性。
系统性是货币政策规则的中心内容。
根据系统性的要求，货币当局必须建立系统性的反应机制，以考虑私人部门的预期行为，使这一时期的货币政策优化。
货币政策规则的主要好处是，所制定的决策是用于各种不同的情况，而不是以各个个别案例为基础进行设定，这种决策对于预期具有积极的作用。
货币政策规则的一般形式是：()****100t t t t t t Y Y i r Y παππβ⎛⎫-=++-+⨯ ⎪⎝⎭3．泰勒规则（Taylor rule ）答：泰勒规则是用来说明货币当局如何适应经济活动来制定利率的规则。
具体说来，泰勒规则是：()***20.50.5100t t t t t t Y Y i Y ⎛⎫-=++⨯-+⨯⨯ ⎪⎝⎭πππ其中，π*是目标通货膨胀率，常数2近似于长期平均实际利率。
多恩布什宏观经济学第十版课后习题答案03
CHAPTER 3Solutions to the Problems in the TextbookConceptual Problems:1. The production function provides a quantitative link between inputs and output. For example, theCobb-Douglas production function mentioned in the text is of the form:Y = F(N,K) = AN1-θKθ,where Y represents the level of output. (1 - θ) and θ are weights equal to the shares of labor (N) and capital (K) in production, while A is often used as a measure for the level of technology. It can be easily shown that labor and capital each contribute to economic growth by an amount that is equal to their individual growth rates multiplied by their respective share in income.2. The Solow model predicts convergence, that is, countries with the same production function, savingsrate, and population growth will eventually reach the same level of income per capita. In other words,a poor country may eventually catch up to a richer one by saving at the same rate and makingtechnological innovations. However, if these countries have different savings rates, they will reach different levels of income per capita, even though their long-term growth rates will be the same.3. A production function that omits the stock of natural resources cannot adequately predict the impactof a significant change in the existing stock of natural resources on the economic performance of a country. For example, the discovery of new oil reserves or an entirely new resource would have a significant effect on the level of output that could not be predicted by such a production function.4. Interpreting the Solow residual purely as technological progress would ignore, for example, theimpact that human capital has on the level of output. In other words, this residual not only captures the effect of technological progress but also the effect of changes in human capital (H) on the growth rate of output. To eliminate this problem we can explicitly include human capital in the production function, such thatY = F(K,N,H) = AN a K b H c with a + b + c = 1.Then the growth rate of output can be calculated as∆Y/Y = ∆A/A + a(∆N/N) + b(∆K/K) + c(∆H/H).5. The savings function sy = sf(k) assumes that a constant fraction of output is saved. The investmentrequirement, that is, the (n + d)k-line, represents the amount of investment needed to maintain a constant capital-labor ratio (k). A steady-state equilibrium is reached when saving is equal to the investment requirement, that is, when sy = (n + d)k. At this point the capital-labor ratio k = K/N is not changing, so capital (K), labor (N), and output (Y) all must be growing at the same rate, that is, the rate of population growth n = (∆N/N).6. In the long run, the rate of population growth n = (∆N/N) determines the growth rate of thesteady-state output per capita. In the short run, however, the savings rate, technological progress, and the rate of depreciation can all affect the growth rate.7. Labor productivity is defined as Y/N, that is, the ratio of output (Y) to labor input (N). A surge inlabor productivity therefore occurs if output grows at a faster rate than labor input. In the U.S. we have experienced such a surge in labor productivity since the mid-1990s due to the enormous growth in GDP. This surge can be explained from the introduction of new technologies and more efficient use of existing technologies. Many claim that the increased investment in and use of computer technology has stimulated economic growth. Furthermore, increased global competition has forced many firms to cut costs by reorganizing production and eliminating some jobs. Thus, with large increases in output and a slower rate of job creation we should expect labor productivity to increase. (One should also note that a higher-skilled labor force also can contribute to an increase in labor productivity, since the same number of workers can produce more output if workers are more highly skilled.)Technical Problems:1.a. According to Equation (2), the growth of output is equal to the growth in labor times the labor shareplus the growth of capital times the capital share plus the rate of technical progress, that is, ∆Y/Y = (1 - θ)(∆N/N) + θ(∆K/K) + ∆A/A, where1 - θ is the share of labor (N) and θ is the share of capital (K). Thus if we assume that the rate oftechnological progress (∆A/A) is zero, then output grows at an annual rate of 3.6 percent, since ∆Y/Y = (0.6)(2%) + (0.4)(6%) + 0% = 1.2% + 2.4% = + 3.6%,1.b. The so-called "Rule of 70" suggests that the length of time it takes for output to double can becalculated by dividing 70 by the growth rate of output. Since 70/3.6 = 19.44, it will take just under 20 years for output to double at an annual growth rate of 3.6%,1.c. Now that ∆A/A = 2%, we can calculate economic growth as∆Y/Y = (0.6)(2%) + (0.4)(6%) + 2% = 1.2% + 2.4% + 2% = + 5.6%.Thus it will take 70/5.6 = 12.5 years for output to double at this new growth rate of 5.6%.2.a. According to Equation (2), the growth of output is equal to the growth in labor times the labor shareplus the growth of capital times the capital share plus the growth rate of total factor productivity (TFP), that is,∆Y/Y = (1 - θ)(∆N/N) + θ(∆K/K) + ∆A/A, where1 - θ is the share of labor (N) and θ is the share of capital (K). In this example θ = 0.3; therefore,if output grows at 3% and labor and capital grow at 1% each, then we can calculate the change in TFP in the following way3% = (0.3)(1%) + (0.7)(1%) + ∆A/A ==> ∆A/A = 3% - 1% = 2%,that is, the growth rate of total factor productivity is 2%.2.b. If both labor and the capital stock are fixed and output grows at 3%, then all this growth has to becontributed to the growth in factor productivity, that is, ∆A/A = 3%.3.a. If the capital stock grows by ∆K/K = 10%, the effect on output would be an additional growth rate of∆Y/Y = (.3)(10%) = 3%.3.b. If labor grows by ∆N/N = 10%, the effect on output would be an additional growth rate of∆Y/Y = (.7)(10%) = 7%.3.c. If output grows at ∆Y/Y = 7% due to an increase in labor by ∆N/N = 10%, and this increase in laboris entirely d ue to population growth, then per capita income would decrease and people’s welfare would decrease, since∆y/y = ∆Y/Y - ∆N/N = 7% - 10% = - 3%.3.d. If this increase in labor is due to an influx of women into the labor force, the overall population doesnot increase and income per capita would increase by ∆y/y = 7%. Therefore people's welfare would increase.4. Figure 3-4 shows output per head as a function of the capital-labor ratio, that is, y = f(k). Thesavings function is sy = sf(k), and it intersects the straight (n + d)k-line, representing the investment requirement. At this intersection, the economy is in a steady-state equilibrium. Now let us assume that the economy is in a steady-state equilibrium before the earthquake hits, that is, the steady-state capital-labor ratio is currently k*. Assume further, for simplicity, that the earthquake does not affect people's savings behavior.If the earthquake destroys one quarter of the capital stock but less than one quarter of the labor force, then the capital-labor ratio falls from k*to k1 and per-capita output falls from y* to y1. Now saving is greater than the investment requirement, that is, sy1 > (d + n)k1, and the capital stock and the level of output per capita will grow until the steady state at k* is reached again.However, if the earthquake destroys one quarter of the capital stock but more than one quarter of the labor force, then the capital-labor ratio increases from k*to k2. Saving now will be less than the investment requirement and thus the capital-labor ratio and the level of output per capita will fall until the steady state at k* is reached again.If exactly one quarter of both the capital stock and the labor stock are destroyed, then the steady state is maintained, that is, the capital-labor ratio and the output per capita do not change.If the severity of the earthquake has an effect on peoples’ savings behavior, then the savings function sy = sf(k) will move either up or down, depending on whether the savings rate (s) increases (if people save more, so more can be invested in an effort to rebuild) or decreases (if people save less, since they decide that life is too short not to live it up).k1k*k2 k5.a. An increase in the population growth rate (n) affects the investment requirement, and the (n + d)k-linegets steeper. As the population grows, more saving must be used to equip new workers with the same amount of capital that the existing workers already have. Therefore output per capita (y) will decrease as will the new optimal capital-labor ratio, which is determined by the intersection of the sy-curve and the (n1 + d)k-line. Since per-capita output will fall, we will have a negative growth rate in the short run. However, the steady-state growth rate of output will increase in the long run, since it will be determined by the new and higher rate of population growth.yy oy1k1k o k5.b. Starting from an initial steady-state equilibrium at a level of per-capita output y*, the increase in thepopulation growth rate (n) will cause the capital-labor ratio to decline from k* to k1. Output per capita will also decline, a process that will continue at a diminishing rate until a new steady-state level is reached at y1. The growth rate of output will gradually adjust to the new and higher level n1.yy*y1t o t1tkk*k1t o t1t6.a. Assume the production function is of the formY = F(K, N, Z) = AK a N b Z c==>∆Y/Y = ∆A/A + a(∆K/K) + b(∆N/N) + c(∆Z/Z), with a + b + c = 1.Now assume that there is no technological progress, that is, ∆A/A = 0, and that capital and labor grow at the same rate, that is, ∆K/K = ∆N/N = n. If we also assume that all natural resources available are fixed, such that ∆Z/Z = 0, then the rate of output growth will be∆Y/Y = an + bn = (a + b)n.In other words, output will grow at a rate less than n since a + b < 1. Therefore output per worker will fall.6.b. If there is technological progress, that is, ∆A/A > 0, then output will grow faster than before, namely∆Y/Y = ∆A/A + (a + b)n.If ∆A/A > c, then output will grow at a rate larger than n, in which case output per worker will increase.6.c. If the supply of natural resources is fixed, then output can only grow at a rate that is smaller than therate of population growth and we should expect limits to growth as we run out of natural resources.However, if the rate of technological progress is sufficiently large, then output can grow at a rate faster than population, even if we have a fixed supply of natural resources.7.a. If the production function is of the formY = K1/2(AN)1/2,and A is normalized to 1, then we haveY = K1/2N1/2.In this case capital's and labor's shares of income are both 50%.7.b. This is a Cobb-Douglas production function.7.c. A steady-state equilibrium is reached when sy = (n + d)k.From Y = K1/2N1/2 ==> Y/N = K1/2N-1/2==> y = k1/2==>sk1/2= (n + d)k ==> k-1/2 = (n + d)/s = (0.07 + 0.03)/(.2) = 1/2 ==> k1/2= 2 = y ==> k = 4 .8.a. If technological progress occurs, then the level of output per capita for any given capital-labor ratioincreases. The function y = f(k) increases to y = g(k), and thus the savings function increases from sf(k) to sg(k).y2k1k2k8.b. Since g(k) > f(k), it follows that sg(k) > sf(k) for each level of k. Therefore theintersection of the sg(k)-curve with the (n + d)k-line is at a higher level of k. The new steady-state equilibrium will now be at a higher level of saving and output per capita, and at a higher capital-labor ratio.8.c. After the technological progress occurs, the level of saving and investment will increaseuntil a new and higher optimal capital-labor ratio is reached. The ratio of investment to capital will also increase in the transition period, since more has to be invested to reach the higher optimal capital-labor ratio.kk2k1t1t2t9. The Cobb-Douglas production function is defined asY = F(N,K) = AN1-θKθ.The marginal product of labor can then be derived asMPN = (∆Y)/(∆N) = (1 - θ)AN-θKθ = (1 - θ)AN1-θKθ/N = = (1 - θ)(Y/N)==> labor's share of income = [MPN*(N)]/Y = (1 - θ)(Y/N)*[(N)/(Y)] = (1 - θ)。
多恩布什宏观经济学第十版课后答案
宏观经济学第二章概念题1．如果政府雇用失业工人，他们曾领取TR美元的失业救济金，现在他们作为政府雇员支取TR美元，不做任何工作，GDP会发生什么情况？请解释。
答：国内生产总值指一个国家（地区）领土范围，本国（地区）居民和外国居民在一定时期内所生产和提供的最终使用的产品和劳务的价值。
用支出法计算的国内生产总值等于消费C、投资I、政府支出G和净出口NX之和。
从支出法核算角度看：C、I、NX保持不变，由于转移支付TR美元变成了政府对劳务的购买即政府支出增加，使得G增加了TR美元，GDP会由于G的增加而增加。
2．GDP和GNP有什么区别？用于计算收入/产量是否一个比另一个更好呢？为什么？答：（1）GNP和GDP的区别GNP指在一定时期内一国或地区的国民所拥有的生产要素所生产的全部最终产品（物品和劳务）的市场价值的总和。
它是本国国民生产的最终产品市场价值的总和，是一个国民概念，即无论劳动力和其他生产要素处于国内还是国外，只要本国国民生产的产品和劳务的价值都记入国民生产总值。
GDP指一定时期内一国或地区所拥有的生产要素所生产的全部最终产品（物品和劳务）的市场价值的总和。
它是一国范围内生产的最终产品，是一个地域概念。
两者的区别：在经济封闭的国家或地区，国民生产总值等于国内生产总值；在经济开放的国家或地区，国民生产总值等于国内生产总值加上国外净要素收入。
两者的关系可以表示为：GNP=GDP+[本国生产要素在其他国家获得的收入（投资利润、劳务收入）-外国生产要素从本国获得的收入]。
（2）使用GDP比使用GNP用于计量产出会更好一些，原因如下：1）从精确度角度看，GDP的精确度高；2）GDP衡量综合国力时，比GNP好；3）相对于GNP而言，GDP是对经济中就业潜力的一个较好的衡量指标。
由于美国经济中GDP和GNP的差异非常小，所以在分析美国经济时，使用这两种的任何一个指标，造成的差异都不会大。
但对于其他有些国家的经济来说明，这个差别是相当大的，因此，使用GDP作为衡量指标会更好。
多恩布什宏观经济学第十版课后习题答案02
多恩布什宏观经济学第十版课后习题答案02CHAPTER 2Solutions to Problems in the Textbook:Conceptual Problems:1. Government transfer payments (TR) do not arise out of anyproduction activity and are thus not counted in the value of GDP. If the government hired the people who currently receive transfer payments, then their wages would be counted as part of government purchases (G), which is counted in GDP. Therefore GDP would rise.2.a. If the firm buys a car for an executive's use, the purchase counts asinvestment (I). But if the firm pays the executive a higher salary and she then buys a car, the purchase is counted as consumption (C).2.b. The services that a homemaker provides are not counted in GDP(regardless of their value). However, if an individual officially hires his or her spouse to perform household duties at a certain wage rate, then the wages earned will be counted in GDP and GDP will increase.2.c. If you buy a German car, consumption (C) will increase but netexports (NX = X - Q) will decrease. Overall GDP will increase by the value added at the foreign car dealership, since the import price is likely to be less than the sales price. If you buy an American car, consumption and thus GDP will increase. (Note: If the car you buy comes out of the car dealer's inventory, then the increase in C will bepartially offset be a decline in I, and GDP will again only increase by the value added.)3. GDP is the market value of all final goods and services currentlyproduced within the country. (The U.S. GDP includes the value of the Hondas produced by a Japanese-owned assembly plant that is located in the U.S., but it does not include the value of Nike shoes that are produced by an American-owned shoe factory located in Malaysia.) GNP is the market value of all final goods and services currently produced using assets owned by domestic residents. (Here the value of the Hondas produced by a Japanese-owned Honda plant is not counted but the value of the Nikes by the American-owned shoe plant is.) Neither is necessarily a better measure of the output of a nation.The actual value of the GDP and GNP for the U.S. is fairly close.4. The NDP (net domestic product) is defined as GDP minusdepreciation. Depreciation measures the value of the capital that wears out during the production process and has to be replaced. Therefore NDP comes closer to measuring the net amount of goods produced in this country. If this is what you want to measure, then NDP should be used.5. Increases in real GDP do not necessarily mean increases in welfare.For example, if the population of a country increases by more than real GDP, then the population of the country is on average worse off.Also some increases in output come from welfare reducing events. For example, increased pollution may cause more lung cancer, and the treatment of the lung cancer will contribute toGDP. Similarly, an increase in crime may lead to overtime work for police officers, whose increased salary will increase GDP. But the welfare of the people in the country may not have increased in either case. On the other hand, GDP does not always accurately measure quality improvements in goods or services (faster computers or improved health care) that improve people's welfare.6. The CPI (consumer price index) and the PPI (producer price index)are both measured by looking at a certain market basket. The CPI's basket contains mostly finished goods and services that consumers tend to buy regularly in their daily lives. The PP I’s basket contains raw materials and semi-finished goods, that is, it measures costs to the producer of a product and its first user. The CPI is a concurrent economic indicator, whereas the PPI is a leading economic indicator.7. T he GDP-deflator is a price index that covers the average priceincrease of all final goods and services currently produced within an economy. It is defined as the ratio of current nominal GDP to current real GDP. Nominal GDP is measured in current dollars, while real GDP is measured in so-called base-year dollars. Even though early estimates of the GDP-deflator tend to be unreliable, the GDP-deflator can be a more useful price index than the CPI or PPI (both of which are fixed market baskets). This is true for two reasons: first it measures a much wider cross-section of goods and services; second, a fixed market basket cannot account for people substituting away from goods whose relative prices have changed, while the GDP-deflator, which includes all goods and services produced within the country, can.8. If nominal GDP has suddenly doubled, it is most likely due to anincrease in the average price level. Therefore, the first thing you would want to check is by how much the GDP-deflator has changed, to calculate by how much real output (GDP) has changed. If nominal GDP and the GDP-deflator have both doubled, then real GDP should be the same.9. Assume the loan you made yields you an annual nominal return of 7%.If the rate of inflation is 4%, then your rate of return in real terms isonly 3%. If, on the other hand, if inflation rate is 10%, then you will actually get a negative real rate of return, that is, you will lose 3% of your purchasing power. One way to protect yourself against such a loss of purchasing power is to adjust the interest rate for inflation, that is, to index the loan. In other words, you can require that, in addition to the specified interest rate of the loan of, let’s say, 3%, the borrower also has to pay an inflation premium equal to the percentage change in the CPI. In this case, a real rate of return of 3% would be guaranteed.Technical Problems:1. The text calculates the change in real GDP in 1992 prices in thefollowing way:[RGDP01- RGDP92]/RGDP92= [3.50 - 1.50]/1.50 = 1.33 = 133%.To calculate the change in real GDP in 2001 prices, we first have to calculate the GDP of 1992 in 2001 prices. Thus we take the quantities consumed in 1992 and multiply them by the prices of 2001, as follows:Beer 1 at $2.00 = $2.00Skittles 1 at $0.75 = $0.75_______________________________Total $2.75The change in real GDP can now be calculated as[6.25 - 2.75]/2.75 = 1.27 = 127%.We can see that the growth rate of real GDP calculated this way is roughly the same as the growth rate calculated above.2.a. The relationship between private domestic saving, investment, thebudget deficit and net exports is shown by the following identity:S - I ≡ (G + TR - TA) + NX.Therefore, if we assume that transfer payments (TR) remain constant, then an increase in taxes (TA) has to be offset either by an increase in government purchases (G), a decrease in net exports (NX), or a decrease in the difference between saving (S) and investment (I).2.b. From the equation YD ≡C + S it follows that an increase indisposable income (YD) will be reflected in an increase in consumption (C), saving (S), or both.2.c. From the equation YD ≡ C + S it follows that when eitherconsumption (C) or saving (S) increases, disposable income (YD) must increase as well.3.a. Since depreciation D = I g - I n = 800 - 200 = 600 ==>NDP = GDP - D = 6,000 - 600 = 5,4003.b. From GDP = C + I + G + NX ==> NX = GDP - C - I - G ==>NX = 6,000 - 4,000 - 800 - 1,100 = 100.3.c. BS = TA - G - TR ==> (TA - TR) = BS + G ==> (TA - TR) = 30 +1,100 = 1,1303.d. YD = Y - (TA - TR) = 5,400 - 1,130 = 4,2703.e. S = YD - C = 4,270 - 4,000 = 2704.a. S = YD - C = 5,100 - 3,800 = 1,3004.b. From S - I = (G + TR - TA) + NX ==> I = S - (G + TR - TA) - NX= 1,300 - 200 - (-100) = 1,200.4.c. From Y = C + I + G + NX ==> G = Y - C - I - NX ==>G = 6,000 - 3,800 - 1,200 - (-100) = 1,100.Also: YD = Y - TA + TR ==> TA - TR = Y - YD = 6,000 - 5,100 ==> TA - TR = 900From BS = TA - TR - G ==> G = (TA - TR) - BS = 900 - (-200) ==> G = 1,1005. According to Equation (2) in the text, the value of total output (inbillions of dollars) can be calculated as: Y = labor payments + capital payments + profits = $6 + $2 + $0 = $86.a. Since nominal GDP is defined as the market value of all final goodsand services currently produced in this country, we can only measure the value of the final product (bread), and therefore we get $2 million (since 1 million loaves are sold at $2 each).6.b. An alternative way of measuring total GDP would be to calculate allthe value added at each step of production. The total value of the ingredients used by the bakeries can be calculated as: 1,200,000 pounds of flour ($1 per pound) = 1,200,000100,000 pounds of yeast ($1 per pound) = 100,000100,000 pounds of sugar ($1 per pound) = 100,000100,000 pounds of salt ($1 per pound) = 100,000________________________________________________________ __= 1,500,000Since $2,000,000 worth of bread is sold, the total value added at the bakeries is $500,000.7. If the CPI increases from 2.1 to 2.3, the rate of inflation can becalculated in the following way:rate of inflation = (2.3 - 2.1)/2.1 = 0.095 = 9.5%The CPI often overstates inflation, since it is calculated by using afixed market basket of goods and services. But the fixed weights in the CPI's market basket cannot capture the tendency of consumers to substitute away from goods whose relative prices have increased.Therefore, the CPI will overstate the increase in consumers' expenditures.8.The real interest rate (r) is defined as the nominal interest rate (i)minus the rate of infla tion (π). Therefore the nominal interest rate is the real interest rate plus the rate of inflation, ori = r + π = 3% + 4% = 7%.。
宏观经济学第十版第二章课后习题完美精简中文版
多恩布什宏观经济学第十版第二章课后习题答案完美中文精简版概念题1，他们作为政府雇员支取TR美元，但是不做任何工作，实际上就是加大了政府支出，GDP会增长。
2，a..厂商为经理买车应该看成投资，经理自己购买轿车则是消费。
b.雇佣配偶的行为是消费，计算GDP时会被计入；而无偿要求她担任此工作则是无形中忽略掉了消费环节，不计入GDP。
c.买美国轿车会使GDP增长，买德国车也会使GDP增加，但是会减少净出口。
3，GDP与GNP的区别在于：GNP是指一个国家(或地区)所有国民在一定时期内新生产的产品和服务价值的总和。
GNP是按国民原则核算的，只要是本国(或地区)居民，无论是否在本国境内(或地区内)居住，其生产和经营活动新创造的增加值都应该计算在内。
GDP是指一个国家(或地区)在一定时期内所有常住单位生产经营活动的全部最终成果。
GDP是按国土原则核算的生产经营的最终成果。
使用GDP计量产出更好，GDP的精确度高。
4，NDP是国内生产净值，NDP是从国内生产总值GDP中扣除资本折旧得到的。
如果用于计算产量，它比GDP更接近产品价值，但是折旧率是人来计算，所以会存在一定误差，在计算数值非常大时用GDP计算比较好。
5，GDP的增加不代表福利的增加，比如说GDP增加，同时人口也增长了，一平均，每个人的GDP没有变化。
我觉得最大的问题是人口问题，人口的增长和减少对人均GDP有影响。
6，CPI居民消费价格指数，是反映与居民生活有关的商品及劳务价格统计出来的物价变动指标，通常作为观察通货膨胀水平的重要指标。
PPI是衡量企业购买的一篮子物品和劳务的总费用。
从消费者的立场计算时我会选择用CPI计算。
7，GDP紧缩指数=（名义GDP/实际GDP） *100区别答不出。
8，物价是否翻了一倍，以及GDP紧缩指数有没有变化。
9，伤心。
以实际利率说明的，将要支付更少利息。
技术题12，b．收入增加意味着可支配收入增加，那么此时就能够购买更多的产品。
对外经贸大学金融学考研多恩布什《宏观经济学》课后题及答案
2． 什么时候一国出现对外平衡？出现内部平衡？是其中任一个还是两个都是政策目标。 答：当国际收支保持平衡时，就会出现外部平衡；外部平衡指一国经济发展和世界经济相协 调的状态，主要指标是国际收支保持基本平衡，没有大量的赤字或赢余。 当国内产出处于充分就业时就出现内部平衡。指一国国内经济处于稳定、协调增长的状态， 主要指标是经济达到充分就业水平而又没有通货膨胀。 外部平衡与内部平衡构成了宏观经济政策的两大目标。 在微观层次上， 采取适当的贸易鼓励 政策，加强技术创新，提高劳动生产率，增强本国产品的国际竞争力；在宏观层次上，通过 财政政策和货币政策的有机配合，在充分就业、工资水平较高的条件下，仍能维持国际收支 平衡。所以，要使二者同时达到均衡，必须综合运用货币政策和财政政策。
3． （第三章第三题）再假定资本与劳动的份额分别是 0.3 和 0.7。 A．资本存量增长 10%对产出有何影响？ B．劳动数量扩大 10%有何影响？
更多资料请到易研官网 下载
C．如果劳动的增加完全归因于人口增长，由此引起产出增长会对人民福利有影响吗？ D．如果劳动的增长归因于妇女涌入劳动场所，结果又将会怎样？ 答： A： 根据公式Y/Y = (1 - )(N/N) + (K/K) + A/A,可知， 其他条件不变， K/K = 10%，
更多资料请到易研官网 下载
技术题：
1． （第二章第一题）在本书中，我们在表 2-3 的假设经济中，用 1992 年价格计算真实 GDP 的变动。计算 1992-1998 年真实 GDP 的变动，利用同一数据但以 1998 年价格计算。你的 回答应该证明，用来计算真实 GDP 使用的价格确实是影响增长率的计算，但通常影响不太 大。
1． 解释当资本完全流动时，货币政策如何以及为什么会保持其有效性。 答：资本完全流动：指投资者能在其选定的任何国家以低交易成本，迅速且无限制地购买资 产。 货币政策保持有效性的方法：扩张性的货币政策降低了利率，同时由于资本是完全流动的， 这将会导致资金的流出，资金的流出将会导致货币贬值。出口商品的价格会下降，外国人购 买时就会更便宜， 这将会导致对出口商品的更大需求。 出口的增加将会带来总需求和国民收 入的增加。在资本具有完全流动性的固定汇率制下，财政政策高度有效。财政扩张会提高利 率，从而使中央银行增加货币存量，以保持汇率的固定不变。所以，在实施货币政策时， 应 该同时采取相应的财政政策，从而保持货币政策的有效性。 货币政策要保持其有效性的原因： 在固定汇率制与资本完全流动的情况下， 货币政策无力影 响产出。通过增加货币存量，来降低本国利率的任何企图，都将引起资本大量外流，引起货 币贬值，从而迫使中央银行不得不以外币购买本国货币，进行抵消。在资本流动的固定汇率 制下，中央银行不能独立运用货币政策，所以要采取配套措施来保持货币政策的有效性。
多恩布什《宏观经济学》课后习题详解(衰退与萧条)【圣才出品】
第21章衰退与萧条一、概念题1．大萧条（Great Depression）答：大萧条指1929年至1939年之间发生的全球性经济大衰退，是以商业和经济运营普遍衰退为特征的一种经济状况。
1929～1933年的萧条——“世界经济衰退”比任何一次经济衰退的影响都要深远得多。
这次经济萧条是以农产品价格下跌为起点的，农业衰退由于金融的大崩溃而进一步恶化，尤其在美国，一股投机热导致大量资金从欧洲抽回，随后在1929年10月发生了令人恐慌的华尔街股市暴跌。
在全球范围内，经济衰退造成大规模的持续失业；资本的短缺在所有的工业化国家中都带来了出口和国内消费的锐减；这场灾难还使中欧和东欧许多国家的制度遭到破产。
根据凯恩斯的理论，大萧条是因为有效需求不足而产生的，所以政府的任务是扩大有效需求。
2．大衰退（Great Recession）答：大衰退指的是一场在2007年8月9日开始浮现的金融危机引发的经济衰退，始于美国房地产市场，不断深化并传播到全球，从金融市场传递到商品和服务市场。
大量的低成本抵押贷款，特别是给那些收入太低而不足以支付所购买房屋者的贷款，导致了房价的疯狂上涨。
只要房屋价格继续上涨，房屋所有人就能通过再融资偿还最初的抵押贷款。
当然，一旦房价停止上涨，房屋所有人将只剩下他们难以偿付的贷款，而且不能再融资。
大部分银行通过抵押贷款证券化在金融市场卖掉了抵押贷款。
而当存在真实风险时这些证券被作为无风险证券交易，加上金融衍生品的繁荣发展并被那些对赌注风险毫不知情的投资者不断交易，导致了次级房屋信贷危机的爆发，投资者开始对按揭证券的价值失去信心，引发了大衰退。
3．新政（New Deal）答：新政又称“罗斯福新政”，指面对1929～1933年的世界经济大危机，1933年罗斯福接任美国总统后为挽救经济所采取的一系列社会、经济政策的总称。
新政主要包括通过国会制定了《紧急银行法令》《国家产业复兴法》《农业调整法》等法案，其主旨是强化政府干预，通过采取一系列发展国家垄断资本主义的措施来克服严重的信贷危机及经济衰退。
多恩布什宏观经济学答案
Chapter 2 national income accountingTechnical Problems1.The text calculates the change in real GDP in 1996 prices in the following way:[RGDP04 - RGDP96]/RGDP96 = [3.50 - 1.50]/1.50 = 1.33 = 133%.To calculate the change in real GDP in 2004 prices, we first have to calculate the GDP of 1996 in 2004 prices.Thus we take the quantities consumed in 1996 and multiply them by the prices of 2004, as follows:B eer 1 at $2.00 = $2.00Skittles 1 at $0.75 = $0.75_______________________________Total $2.75The change in real GDP can now be calculated as [6.25 - 2.75]/2.75 = 1.27 = 127%.We can see that the growth rate of real GDP calculated this way is roughly the same as the growth rate calculated above.2.a. The relationship between private domestic saving, private domestic investment, the budget deficit, and netexports is shown by the following identity:S - I ≡ (G + TR - TA) + NX.Therefore, if we assume that transfer payments (TR) remain constant, an increase in taxes (TA) has to be offset either by an increase in government purchases (G), an increase in net exports (NX), or a decrease in the difference between private domestic saving (S) and private domestic investment (I).2.b.From the equation YD ≡ C + S it follows that an increase in disposable income (YD) will be reflected in anincrease in consumption (C), saving (S), or both.2.c.From the equation YD ≡ C + S it follows that when either consumption (C) or saving (S) increases, disposableincome (YD) must increase as well.3.a. Since depreciation is defined as D = I g - I n = 800 - 200 = 600 ==>NDP = GDP - D = 6,000 - 600 = 5,400.3.b.From GDP = C + I g + G + NX ==> NX = GDP - C – I g - G ==>NX = 6,000 - 4,000 - 800 - 1,100 = 100.3.c.BS = TA - G - TR ==> (TA - TR) = BS + G ==> (TA - TR) = 30 + 1,100 = 1,1303.d.YD = Y - (TA - TR) = 6,000 - 1,130 = 4,8703.e. S = YD - C = 4,870 - 4,000 = 8704.a. S = YD - C = 5,100 - 3,800 = 1,3004.b.From S - I = (G + TR - TA) + NX ==> I = S - (G + TR - TA) - NX = 1,300 - 200 - (-100) = 1,200.2704.c.From Y = C + I + G + NX ==> G = Y - C - I - NX ==>G = 6,000 - 3,800 - 1,200 - (-100) = 1,100.Also: YD = Y - TA + TR ==> TA - TR = Y - YD = 6,000 - 5,100 ==> TA - TR = 900From BS = TA - TR - G ==> G = (TA - TR) - BS = 900 - (-200) ==> G = 1,100.5.According to Equation (2) in the text, the value of total output (in billions of dollars) can be calculated as: Y =labor payments + capital payments + profits = $6 + $2 + $0 = $8.6.a.Since nominal GDP is defined as the market value of all final goods and services currently produced in thiscountry, we can only measure the value of the final product (bread), and therefore we get $2 million (since 1 million loaves are sold at $2 each).6.b.An alternative way of measuring GDP is to calculate all the value added at each step of production. The totalvalue of the ingredients used by the bakeries can be calculated as:1,200,000 pounds of flour ($1 per pound) = 1,200,000100,000 pounds of yeast ($1 per pound) = 100,000100,000 pounds of sugar ($1 per pound) = 100,000100,000 pounds of salt ($1 per pound) = 100,000__________________________________________________________= 1,500,000Since $2,000,000 worth of bread is sold, the total value added at the bakeries is $500,000.7.If the CPI increases from 2.1 to 2.3, the rate of inflation can be calculated in the following way:rate of inflation = (2.3 - 2.1)/2.1 = 0.095 = 9.5%.The CPI often overstates inflation, since it is calculated by using a fixed market basket of goods and services.But the fixed weights in the CPI's market basket cannot capture the tendency of consumers to substitute away from goods whose relative prices have increased. Quality improvements in goods also often are not adequately taken into account. Therefore, the CPI will overstate the increase in consumers' expenditures.8.The real interest rate (r) is defined as the nominal interest rate (i) minus the rate of inflation (π). Therefore thenominal interest rate is the real interest rate plus the rate of inflation, ori = r + π = 3% + 4% = 7%.Chapter 3Growth theory, exogenous.1.a.According to Equation (2), the growth of output is equal to the growth in lab or times labor’s share ofincome plus the growth of capital times capital’s share of income plus the rate of technical progress, that is,∆Y/Y = (1 - θ)(∆N/N) + θ(∆K/K) + ∆A/A, where2711 - θ is the share of labor (N) and θ is the share of capital (K). Therefore, if we assume that therate of technological progress is zero (∆A/A = 0), output grows at an annual rate of 3.6 percent, since ∆Y/Y = (0.6)(2%) + (0.4)(6%) + 0% = 1.2% + 2.4% = + 3.6%,1.b.The so-called "Rule of 70" suggests that the length of time it takes for output to double can becalculated by dividing 70 by the growth rate of output. Since 70/3.6 = 19.44, it will take just under 20 years for output to double at an annual growth rate of 3.6%,1.c.Now that ∆A/A = 2%, we can calculate economic growth as∆Y/Y = (0.6)(2%) + (0.4)(6%) + 2% = 1.2% + 2.4% + 2% = + 5.6%.Thus it will take 70/5.6 = 12.5 years for output to double at this new growth rate of 5.6%.2.a.According to Equation (2), the growth of output is equal to the growth in labor times the labor shareplus the growth of capital times the capital share plus the growth rate of total factor productivity, that is,∆Y/Y = (1 - θ)(∆N/N) + θ(∆K/K) + ∆A/A, where1 - θ is the share of labor (N) and θ is the share of capital (K). In this example θ = 0.3; therefore,if output grows at 3% and labor and capital grow at 1% each, we can calculate the change in total factor productivity in the following way3% = (0.7)(1%) + (0.3)(1%) + ∆A/A ==> ∆A/A = 3% - 1% = 2%,that is, the growth rate of total factor productivity is 2%.2.b.If both labor and the capital stock are fixed, that is, ∆N/N = ∆K/K = 0, and output grows at 3%, thenall the growth has to be contributed to the growth in total factor productivity, that is, ∆A/A = 3%.3.a.If the capital stock grows by ∆K/K = 10%, the effect on output will be an additional growth rate of∆Y/Y = (0.3)(10%) = 3%.3.b.If labor grows by ∆N/N = 10%, the effect on output will be an additional growth rate of∆Y/Y = (0.7)(10%) = 7%.3.c.If output grows at ∆Y/Y = 7% due to an increase in labor by ∆N/N = 10% and this increase in labor isentirely due to population growth, then per-capita income will decrease and people’s welfare will decrease, since∆y/y = ∆Y/Y - ∆N/N = 7% - 10% = - 3%.2723.d.If the increase in labor is due to an influx of women into the labor force, the overall population doesnot increase, and income per capita will increase by y/y = 7%. Therefore people's welfare (or at least their living standard) will increase.4.Figure 3-4 shows output per head as a function of the capital-labor ratio, that is, y = f(k). Thesavings function is sy = sf(k) and it intersects the (n + d)k-line, representing the investment requirement. At this intersection, the economy is in a steady-state equilibrium. Now let us assume that the economy is in a steady-state equilibrium before the earthquake hits, that is, the capital-labor ratio is currently k*. Assume further, for simplicity, that the earthquake does not affect pe oples’ savings behavior.If the earthquake destroys one quarter of the capital stock but less than one quarter of the labor force, then the capital-labor ratio will fall from k* to k1 and per-capita output will fall from y* to y1.Now saving is greater than the investment requirement, that is, sy1 > (d + n)k1, and the capital stock and the level of output per capita will grow until the steady state at k* is reached again.However, if the earthquake destroys one quarter of the capital stock but more than one quarter of the labor force, then the capital-labor ratio will increase from k* to k2. Saving (and gross investment) now will be less than the investment requirement and thus the capital-labor ratio and the level of output per capita will fall until the steady state at k* is reached again.If exactly one quarter of both the capital stock and the labor stock are destroyed, then the steady state will be maintained, that is, the capital-labor ratio and the output per capita will not change.If the severity o f the earthquake has an effect on peoples’ savings behavior, the savings function sy = sf(k) will move either up or down, depending on whether the savings rate (s) increases (if people save more, so more can be invested in an effort to rebuild) or decreases (if people save less, since they decide that life is too short not to live it up). But in either case, a new steady-state equilibrium will be reached.k1k k2 k5.a.An increase in the population growth rate (n) affects the investment requirement. As n gets larger, the(n + d)k-line gets steeper. As the population grows, increases in saving and investment will be required to equip new workers with the same amount of capital that existing workers already have.273Since the population will now be growing faster than output, income per capita (y) will decrease anda new optimal capital-labor ratio will be determined by the intersection of the sy-curve and the new(n1 + d)k-line. Since per-capita output will fall, we will have a negative growth rate in the short run.However, the steady-state growth rate of output will increase in the long run, since it will be determined by the new and higher rate of population growth.y oy1k1k o k5.b.Starting from an initial steady-state equilibrium at a level of per-capita output y*, the increase in thepopulation growth rate (n) will cause the capital-labor ratio to decline from k* to k1. Output per capita will also decline, a process that will continue at a diminishing rate until a new steady-state level is reached at y1. The growth rate of output will gradually adjust to the new and higher level n1.yy*y1t o t1tkk*k1t o t1t6.a.Assume the production function is of the formY = F(K, N, Z) = AK a N b Z c==>274∆Y/Y = ∆A/A + a(∆K/K) + b(∆N/N) + c(∆Z/Z), with a + b + c = 1.Now assume that there is no technological progress, that is, ∆A/A = 0, and that capital and labor grow at the same rate, that is, ∆K/K = ∆N/N = n. If we also assume that all available natural resources are fixed, such that ∆Z/Z = 0, then the rate of output growth will be∆Y/Y = an + bn = (a + b)n.In other words, output will grow at a rate less than n since a + b < 1, and output per worker will fall.6.b.If there is technological progress, that is, ∆A/A > 0, then output will grow faster than before, namely∆Y/Y = ∆A/A + (a + b)n.If ∆A/A < cn, output will grow at a lower rate than n, in which case output per worker will still decrease.If ∆A/A = cn, output will grow at the same rate as n, in which case output per worker will remain the same.But if ∆A/A > cn, output will grow at a rate higher than n, in which case output per worker will increase.6.c.If the supply of natural resources is fixed, then output can only grow at a rate that is smaller than therate of population growth and we should expect limits to growth as we run out of natural resources.However, if the rate of technological progress is sufficiently large, then output can grow at a rate faster than population, even if we have a fixed supply of natural resources.7.a.If the production function is of the formY = K1/2(AN)1/2,and A is normalized to 1, we haveY = K1/2N1/2 .In this case, capital's and labor's shares of income are both 50%.7.b.This is a Cobb-Douglas production function.7.c. A steady-state equilibrium is reached when sy = (n + d)k.From Y = K1/2N1/2 ==> Y/N = K1/2N-1/2==> y = k1/2 ==> sk1/2 = (n + d)k==> k-1/2 = (n + d)/s = (0.07 + 0.03)/(.2) = 1/2 ==> k1/2 = 2 = y ==> k = 4 .7.d.At the steady-state equilibrium, output per capita remains constant, since total output grows at thesame rate as the population (7%), as long as there is no technological progress, that is, ∆A/A = 0. But275if total factor productivity grows at ∆A/A = 2%, then total output will grow faster than population, that is, at 7% + 2% = 9%, so output per capita will grow at 2%.8.a.If technological progress occurs, then the level of output per capita for any given capital-labor ratioincreases. The function y = f(k) increases to y = g(k), and thus the savings function increases from sf(k) to sg(k).8.b.Since g(k) > f(k), it follows that sg(k) > sf(k) for each level of k. Therefore, the intersection of thesg(k)-curve with the (n + d)k-line is at a higher level of k. The new steady-state equilibrium will now be at a higher level of saving and output per capita, and at a higher capital-labor ratio.8.c.After the technological progress occurs, the level of saving and investment will increase until a newand higher optimal capital-labor ratio is reached. The investment ratio will increase in the transition period, since more investment will be required to reach the higher optimal capital-labor ratio.9.The Cobb-Douglas production function is defined asY = F(N, K) = AN1-θKθ.The marginal product of labor can then be derived asMP N = (∆Y)/(∆N) = (1 - θ)AN-θKθ = (1 - θ)AN1-θKθ/N = = (1 - θ)(Y/N)== > labor's share of income = [MP N*N]/Y = [(1 - θ)(Y/N)](N/Y) = (1 - θ).Chapter 4Growth theory, endogenous1.a. A production function that displays both a diminishing and a constant marginal product of capital canbe displayed by drawing a curved line (as in an exogenous growth model), followed by an upward-sloping line (as in an endogenous growth model). Such a graph is depicted below.1.b.The first equilibrium (Point A in the graph below) is a stable low-income steady-state equilibrium.Any deviation from that point will cause the economy to eventually adjust again at the same steady-state income level (and capital-output ratio). The second equilibrium (Point B) is an unstable high-income steady-state equilibrium. Any deviation from that point will lead to either a lower income steady-state equilibrium back at Point A (if the capital-labor ratio declines) or ongoing growth (if the capital-labor ratio increases). In the latter case, not only total output but also output per capita continues to grow.1.c. A model like the one in this question can be used to explain how some countries find themselves insituations with no growth and low income while others have ongoing growth and a high level of income. In the first case, a country may have invested mostly in physical capital, leading to some short-term growth at the expense of long-term growth. In the second case, a country may have invested not only in physical capital but also in human capital (education, skills, and training), reaping significant social returns.2762.a.If population growth is endogenous, that is, if a country can influence the rate of population growththrough government policies, then the investment requirement is no longer a straight line. Instead it is curved as depicted below.2.b.The first equilibrium (Point A) is a stable steady-state equilibrium. This is a situation of low incomeand high population growth, indicating that the country is in a poverty trap. The second equilibrium (Point B) is an unstable steady-state equilibrium. This is a situation of medium income and low population growth. The third equilibrium (Point C) is a stable steady-state equilibrium. This is a situation of high income and low population growth. In none of these three cases do we have ongoing growth. For any capital stock k < k B, the economy will adjust to k A, but for any capital stock k > k b (even for k > k c), the economy will adjust to k B. During the adjustment process to any of these two steady-state equilibria, the change in output per capita only will be transitory.2.c.To escape the poverty trap (Point A), a country has several possibilities: First, it can somehow find themeans to increase the capital-labor ratio above a level consistent with Point B (perhaps by borrowing funds or seeking direct foreign investment). Second, it can increase the savings rate such that the savings function no longer intersects the investment requirement curve at either Point A or Point B.Third, it can decrease the rate of population growth through specifically designed policies, such that the investment requirement shifts down and no longer intersects with the savings function at Points A or B.3.a.If we incorporate endogenous population growth into a two-sector model in Problem 2, we get acurved investment requirement line and a production function with first a diminishing and then a constant marginal product of capital as depicted below. (Note that the savings function has the same shape as the production function.)3.b. Here we should have four intersections of the savings function sf(k) and the investment requirement[n(y)+d]k. The first equilibrium (at Point A) is a stable low-income steady-state equilibrium. Any deviation from that point will cause the economy to eventually adjust again at the same steady-state income level (and capital-output ratio). The second equilibrium (at Point B) is an unstable low-income equilibrium. Any deviation from that point will lead to either a lower income steady-state equilibrium at Point A (if the capital-labor ratio declines) or a higher income steady-state equilibrium at Point C (if the capital-labor ratio increases). Since Point C is a stable equilibrium, the economy will settle back at that point again whether the capital stock increases or declines. Point D is again an unstable equilibrium but at a high level of income. Any deviation from that point will lead to either a lower income steady-state equilibrium at Point C (if the capital-labor ratio declines) or ongoing growth (if the capital-labor ratio increases).3.c.This model is more inclusive than either of the two models discussed previously and therefore hasgreater explanatory power. While the graphical analysis is far more complicated, we can now see more clearly that a poor country cannot escape the poverty trap at Point A unless it somehow succeeds in increasing the capital-labor ratio (and thus per-capita income) beyond the level at Point B.4.a.The production function is of the formY = K1/2(AN)1/2 = K1/2(4[K/N]N)1/2= K1/2(4K)1/2 = 2K.From this we can see that a = 2 since277Y = Y/N = 2(K/N) == > y = 2k.4.b.Since a = y/k = 2, it follows that the growth rate of output and capital is∆y/y = ∆k/k = g = sa - (n + d) = (0.1)2 - (0.02 + 0.03) = 0.15 = 15%.4.c.The term "a" in the equation above stands for the marginal product of capital. By assuming that thelevel of labor-augmenting technology (A) is proportional to the capital-labor ratio (k), it is implied that the level of technology depends on the amount of capital per worker that we have, which may not be realistic.4.d.In this model, we have a constant marginal product of capital and therefore we have an endogenousgrowth model.5.a.The production function is of the formY = K1/2N1/2==> Y/N = (K/N)1/2 ==> y = k1/2.From k = sy/(n + d) = sk1/2/(n +d) ==> k1/2 = s/(n + d)==> y* = s/(n + d) = (0.1)/(0.02 + 0.03) = 2==> k* = sy*/(n + d) = (0.1)(2)/(0.02 + 0.03) = 4.5.b.Steady-state consumption equals steady-state income minus steady-state saving (or investment), thatis,c* = y – sy = f(k*) - (n + d)k* .The golden-rule capital stock corresponds to the highest permanently sustainable level of consumption. Steady-state consumption is maximized when the marginal increase in capital produces just enough extra output to cover the increased investment requirement.From c = k1/2 - (n + d)k ==> (∆c/∆k) = (1/2)k-1/2 - (n + d) = 0==> k-1/2 = 2(n + d) = 2(.02 + .03) = .1==> k1/2 = 10 ==> k = 100.Since k* = 4 < 100, we have less capital at the steady state than the golden rule suggests.5.c.From k = sy/(n + d) = sk1/2/(n + d) ==> s = k1/2(n + d) = 10(0.05) = 0.5.5.d.If we have more capital than the golden rule suggests, we are saving too much and do not have theoptimal amount of consumption.Chapter 9Income and spending2781.a. AD = C + I = 100 + (0.8)Y + 50 = 150 + (0.8)YThe equilibrium condition is Y = AD ==>Y = 150 + (0.8)Y ==> (0.2)Y = 150 ==> Y = 5*150 = 750.1.b.Since TA = TR = 0, it follows that S = YD - C = Y - C. ThereforeS = Y - [100 + (0.8)Y] = - 100 + (0.2)Y ==> S = - 100 + (0.2)750 = - 100 + 150 = 50.As we can see S = I, which means that the equilibrium condition is fulfilled.1.c.If the level of output is Y = 800, then AD = 150 + (0.8)800 = 150 + 640 = 790.Therefore the amount of involuntary inventory accumulation is UI = Y - AD = 800 - 790 =10.1.d. AD' = C + I' = 100 + (0.8)Y + 100 = 200 + (0.8)YFrom Y = AD' ==> Y = 200 + (0.8)Y ==> (0.2)Y = 200 ==> Y = 5*200 = 1,000Note: This result can also be achieved by using the multiplier formula:∆Y = (multiplier)(∆Sp) = (multiplier)(∆I) ==> ∆Y = 5*50 = 250,that is, output increases from Y o = 750 to Y1 = 1,000.1.e.From 1.a. and 1.d. we can see that the multiplier is α = 5.2.a.Since the mpc has increased from 0.8 to 0.9, the size of the multiplier is now larger. Therefore weshould expect a higher equilibrium income level than in 1.a.AD = C + I = 100 + (0.9)Y + 50 = 150 + (0.9)Y ==>Y = AD ==> Y = 150 + (0.9)Y ==> (0.1)Y = 150 ==> Y = 10*150 = 1,500.2.b.From ∆Y = (multiplier)(∆I) = 10*50 = 500 ==> Y1 = Y o + ∆Y = 1,500 + 500 = 2,000.2.c.Since the size of the multiplier has doubled from α = 5 to α1 = 10, the change in output (Y) that resultsfrom a change in investment (I) now has also doubled from 250 to 500.3.a. AD = C + I + G + NX = 50 + (0.8)YD + 70 + 200 + 0 =320 + (0.8)[Y - TA + TR]= 320 + (0.8)[Y - (0.2)Y + 100] = 400 + (0.8)(0.8)Y = 400 + (0.64)YFrom Y = AD ==> Y = 400 + (0.64)Y ==> (0.36)Y = 400279==> Y = (1/0.36)400 = (2.78)400 = 1,111.11The size of the multiplier is α = 1/0.36) = 2.78.3.b.BS = tY - TR - G = (0.2)(1,111.11) - 100 - 200 = 222.22 - 300 = - 77.783.c.AD' = 320 + (0.8)[Y - (0.25)Y + 100] = 400 + (0.8)(0.75)Y = 400 + (0.6)YFrom Y = AD' ==> Y = 400 + (0.6)Y ==> (0.4)Y = 400 ==> Y = (2.5)400 = 1,000The size of the multiplier is now reduced to α1 = (1/0.4) = 2.5.3.d.The size of the multiplier and equilibrium output will both increase with an increase in the marginalpropensity to consume. Therefore income tax revenue will also go up and the budget surplus should increase. This can be seen as follows:BS' = (0.25)(1,000) - 100 - 200 = - 50 ==> BS' - BS = - 50 - (-77.78) = + 27.783.e.If the income tax rate is t = 1, then all income is taxed. There is no induced spending and equilibriumincome always increases by exactly the change in autonomous spending. In other words, the size of the expenditure multiplier is 1.From Y = C + I + G ==> Y = C o + c(Y - TA + TR) + I o + G o = C o + c(Y - 1Y + TR o) + I o + G o ==> Y = C o + cTR o + I o + G o = A o==> ∆Y = ∆A o4.On first sight, one may want to conclude that this is an application of the balanced budget theorem,since, as long as Y = 1,000, a change in the tax rate by 5% will cause total tax revenues to change by ∆TA = 50, which is the same as the change in government purchases, that is, ∆G = 50. As long as income (Y) stays the same, the budget surplus will not be affected. However, this combined fiscal policy change will have an effect on national income and, since national income goes up, so does the government’s tax revenue, due to the fact that we have income taxation. Therefore we should expect an increase in the budget surplus. This can easily be shown with a numerical example.For example, in Problem 3.d. we had a situation where the following was given:Y o = 1,000, t o = 0.25, G o = 200 and BS o = - 50.Assume now that t1 = 0.3 and G1 = 250 ==>AD' = 50 + (0.8)[Y - (0.3)Y + 100] + 70 + 250 = 370 + (0.8)(0.7)Y + 80 = 450 + (0.56)Y.From Y = AD' ==> Y = 450 + (0.56)Y ==> (0.44)Y = 450==> Y = (1/0.44)450 = 1,022.73280BS1 = (0.3)(1,022.73) - 100 - 250 = 306.82 - 350 = - 43.18 == > BS1– BS o = -43.18 - (-50) = + 6.82Therefore we see that the budget surplus has increased, since the increase in income tax revenue is larger than the increase in government purchases.5.a.While an increase in government purchases by ∆G = 10 will change intended spending by ∆Sp = 10,a decrease in government transfers by ∆TR = -10 will change intended spending by a smaller amount,that is, by only ∆Sp = c(∆TR) = c(-10). The change in intended spending equals ∆Sp = (1 - c)(10) and equilibrium income should therefore increase by∆Y = (multiplier)(1 - c)10.5.b.If c = 0.8 and t = 0.25, then the size of the multiplier isα = 1/[1 - c(1 - t)] = 1/[1 - (0.8)(1 - 0.25)] = 1/[1 - (0.6)] = 1/(0.4) = 2.5.The change in equilibrium income is∆Y = α(∆A o) = α[∆G + c(∆TR)] = (2.5)[10 + (0.8)(-10)] = (2.5)2 = 55.c.The budget surplus should increase, since the level of equilibrium income has increased and thereforethe level of tax revenues has increased, while the changes in government purchases and transfer payments cancel each other out. Numerically, this can be shown as follows:∆BS = t(∆Y) - ∆TR - ∆G = (0.25)(5) - (-10) - 10 = 1.25Chapter 10Money, interest, fiscal policy1.a. Each point on the IS-curve represents an equilibrium in the expenditure sector. (Note that this is aclosed economy, that is, NX = 0).The IS-curve can be derived by setting actual income equal to intended spending, orY = C + I + G = (0.8)[1 - (0.25)]Y + 900 - 50i + 800 = 1,700 + (0.6)Y - 50i ==>(0.4)Y = 1,700 - 50i ==> Y = (2.5)(1,700 - 50i) ==> Y = 4,250 - 125i.1.b.The IS-curve shows all combinations of the interest rate and output level such that the expendituresector (the goods market) is in equilibrium, that is, actual output equals intended spending. A decrease in the interest rate stimulates investment spending, making intended spending greater than actual output. The resulting unintended inventory decrease leads firms to increase their production until actual output is again equal to intended spending. This means that the IS-curve is downward sloping.1.c.Each point on the LM-curve represents an equilibrium in the money sector. Therefore the LM-curvecan be derived by setting real money supply equal to real money demand, that is,281M/P = L ==> 500 = (0.25)Y - 62.5i ==> Y = 4(500 + 62.5i) ==> Y = 2,000 + 250i.1.d.The LM-curve shows all combinations of the interest rate and level of output such that the moneysector is in equilibrium, that is, the demand for real money balances is equal to the supply of real money balances. An increase in income will increase the demand for real money balances. Given a fixed real money supply, this will lead to an increase in interest rates, which will then reduce the quantity of real money balances demanded until the money market clears again. In other words, the LM-curve is upward sloping.1.e.The level of income (Y) and the interest rate (i) at the equilibrium are determined by the intersectionof the IS-curve with the LM-curve. At this point, the expenditure sector and the money sector are both in equilibrium simultaneously.From IS = LM ==> 4,250 - 125i = 2,000 + 250i ==> 2,250 = 375i ==> i = 6==> Y = 4,250 - 125*6 = 4,250 - 750 ==> Y = 3,500Check: Y = 2,000 + 250*6 = 2,000 + 1,500 = 3,500i125 ISLM62,000 3,500 4,250 Y2.a.As we have seen in 1.a., the value of the expenditure multiplier is α = 2.5. This multiplier is derivedin the same way as in Chapter 9. But now intended spending also depends on the interest rate, so we no longer have Y = αA o, but ratherY = α(A o - bi) = (1/[1 - c + ct])(A o - bi) ==> Y = (2.5)(1,700 - 50i) = 4,250 - 125i.2.b.In the IS-LM model, an increase in government purchases (G) will have a smaller effect on outputthan in the model of the expenditure sector used in Chapter 9, in which interest rates are assumed to be fixed. This can be answered most easily with a numerical example. Assume that government purchases increase by ∆G = 300. The IS-curve shifts parallel to the right by==> ∆IS = (2.5)(300) = 750.Therefore, the equation of the new IS-curve is: Y = 5,000 - 125i.282。