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1 / 66第5章 封闭经济下的一时期宏观经济模型5.1 复习笔记一、政府1．政府行为政府希望购买一定数量的消费品G ，资金来源正是它对典型消费者的征税。
政府在提供公共物品，如国防中应发挥特殊作用。
2．政府预算约束商品在私人部门生产出来后，政府从中购买的数量为G ，剩下的由典型消费者消费，而G 属于外生变量。
外生变量由模型以外的因素决定，而内生变量则由模型本身决定。
在封闭经济模型中，假定政府支出与其他经济部门发生的事情无关，则政府支出是外生变量。
政府必须遵守政府预算约束，它表示为：G ＝T ，即政府的实际购买等于实际税收。
2 / 663．政府政策分析财政政策是指政府对其（购买性）支出、税收、转移性支出和借债的选择。
其中，政府（购买性）支出是用来购买最终商品和服务的，而转移性支出只不过是将购买力从一组人那里重新分配给另一组人。
在预算约束下，政府不能通过借债为其支出筹资，税收收入也不能高于其支出。
政府预算赤字即G －T 总为零。
二、竞争性均衡1．宏观经济模型宏观经济模型是选取外生变量（由模型以外的因素决定，用于模型要解决的问题），来确定内生变量的值，如图5-1所示。
利用模型的过程，就是进行实验以确定外生变量的变化是如何改变内生变量的过程。
图5-1 模型选取外生变量，以确定内生变量3 / 662．竞争性均衡（1）定义竞争性均衡（competitive equilibrium ）是指给定市场价格，经济中每个市场的需求都等于供给的状态。
其中，竞争性是指所有消费者和企业都是价格接受者，当所有消费者和企业的行为一致时，经济就处于均衡中。
市场出清是指所有市场的需求都等于供给。
（2）须满足的四个条件竞争性均衡是在给定外生变量G （政府支出）、z （全要素生产率）和K （资本存量）下，满足下列条件的一组内生数量——C （消费）、N s （劳动供给）、N d （劳动需求）、T （税收）、Y （总产出）以及内生实际工资w 。
宏观经济学第四版课后习题答案第12章国民收入核算1.下列项目是否计入GDP，为什么？（1）政府转移支付；（2）购买一辆用过的卡车；（3）购买普通股票；（4）购买一块地产。
答：（1）不计入。
因为政府转移支付只是简单地通过税收把收入从一个人或一个组织转移到另一个人或另一个组织手中，并没有相应的物品或劳务的交换发生。
（2）不计入。
不是该期的实际生产活动。
（3）不计入。
经济学上所讲的投资是增加或替换资本资产的支出，即购买新厂房、设备和存货的行为，而人们购买债券和股票只是一种交易活动，并不是实际的生产经营活动。
（4）不计入。
同（3）。
2.在统计中，社会保险税增加对GDP、NDP、NI、PI和DPI这五个总量中哪个总量有影响？为什么？答：社会保险税实质上是企业和职工为得到社会保障而支付的保险金，它由政府相关部门按一定比率以税收形式征收。
社会保险税是从NI中扣除的，因此，社会保险税的增加并不影响GDP、NDP和NI，但影响个人收入PI。
3.如果甲乙两国并成一个国家，对GDP总和会有什么影响（假定两国产出不变）？答：有影响。
因为合并前的对外贸易变成合并后的国内贸易。
例如合并前，甲国对乙国有出口200亿，对乙国有进口100亿，顺差100亿。
假定他们分别都没有其他贸易伙伴。
对甲国而言，顺差的100亿为GDP加项；对乙国而言，逆差的100亿为GDP减项，两国GDP的总和中的对外贸易部分因此而抵消，为零。
合并后，甲地生产的产品200亿，乙地生产的产品100亿，对合并后的新国家而言，新增的GDP为300亿，总和增加了。
4.某年发生了以下活动（a）一银矿公司支付7.5万美元给矿工开采了50千克银卖给一银器制造商，售价10万美元；（b）银器制造商支付5万美元工资给工人造了一批项链卖给消费者，售价40万美元。
（1）用最终产品生产法计算GDP；（2）每个生产阶段生产多少价值？用增值法计算GDP。
（3）在生产活动中赚得的工资和利润各共为多少？用收入法计算GDP。
第二部分课后习题第1篇导论和衡量问题第1章导论一、复习题1．宏观经济学的主要鲜明特征是什么？答：（1）宏观经济学的研究对象是众多经济主体的行为。
它关注的是消费者和企业的总体行为、政府的行为、单个国家的经济活动总水平、各国间的经济影响，以及财政政策和货币政策的效应。
（2）宏观经济学侧重于总量研究，强调的问题主要是长期增长和经济周期。
其研究的具体内容包括：①持续经济增长的动力；②经济增长是否有极限；③政府应该如何改变经济增长率，促进经济增长；④经济周期的原因；⑤经济增长在大萧条和第二次世界大战期间发生的剧烈波动是否会重现；⑥政府是否应该采取行动以熨平经济周期。
2．宏观经济学与微观经济学有何异同？答：（1）宏观经济学与微观经济学的联系20世纪70年代以来，微观经济学家与宏观经济学家都在使用非常相似的研究工具。
宏观经济学家用来描述消费者与企业的行为、目标与约束，以及它们之间如何相互影响的经济模型，是根据微观经济学原理建立起来的，而且在分析这些模型和拟合数据时通常都用微观经济学家所用的方法。
宏观经济分析建立在微观经济学原理基础之上。
（2）宏观经济学与微观经济学的区别①研究方法不同微观经济学家侧重个量分析，宏观经济学侧重于总量研究。
②研究内容不同微观经济学研究单个家庭和企业的行为。
因为经济作为一个整体是由许多家庭与企业组成的，在总体水平上的相互影响是单个家庭和企业决策的结果。
宏观经济学有别于微观经济学，因为它涉及的是所有经济主体的选择对经济的总影响，而不是单个消费者或企业的选择对经济的影响，它强调的问题主要是长期增长和经济周期。
3．2011年的普通美国人比1900年的普通美国人富多少？答：2011年的普通的美国人比1900年的普通美国人平均来说富近8倍。
实际人均GDP 是衡量一国居民平均收入水平的指标。
1900年，一个美国人的平均收入是4793美元（以2005年美元计），2011年增加到42733美元（以2005年美元计）。
Chapter 9Credit Market Imperfections: Credit Frictions,Financial Crises and Social SecurityTextbook Question SolutionsQuestions for Review1. Borrowers face higher interest rates than lenders.2. The Ricardian equivalence does not hold. Credit constraint household will not save at least part of thetax cut an consume it.3. Yes, there is room for government intervention, in the form of social security or by holding positivepublic debt.4. Asymmetric information and limited commitment.5. The default premium can increase if more consumers are likely to default.6. As consumers face a higher interest rate when borrowing, they borrow less and thus consume lesstoday.7. Such a borrower must reduce the size of her loan, and thus her consumption. She may also want todefault, thereby increasing the default premium and the interest rate of other borrowers, who also reduce their consumption.8. Pay-as-you-go Social Security always improves the welfare of the first generation to receive benefits.Later generations only see a welfare improvement if the population growth rate exceeds the real rate of interest.9. Fully funded Social Security has no effects as long as taxes collected are less than the optimal amountof saving. If taxes and benefits are larger, then individuals consume less when working and more when retired relative to what they would prefer.10. The government cannot commit not to take care of destitute senior citizens. This leads to an incentivenot to save, at least for the poor. With social security, there should be no destitute senior citizens, and the aggregate savings rate is higher as everyone saves optimally for retirement.Problems1. (a) The government intertemporal budget constraint is, assuming both t and t′ are positive:84 Williamson • Macroeconomics, Fourth Edition 1(1)0(1)bt b at r ′+−=+ (b) We are in a situation where asymmetric information becomes important: the government doesnot know who will be able to pay the future taxes. The relevant interest rate is the onecorresponding to the steeper part of the budget constraint, and the new endowment thus movesthe flatter part down. Consumption choices of the first period consumers are thus impactedthrough a negative income shock, as they have to pay more taxes to compensate for more unpaidtaxes in the future.(c) The Ricardian equivalence does not apply as the change in timing of taxes has changed someconsumption patterns. Indeed, households cannot fully adjust their savings, thus any change inperiodic disposable income has an impact at least for some households.2. (a) The government can only tax in the second period as much as it could get from the collateral:t ′ ≤ pH(b) Now that the government has priority on the collateral, the new collateral constraint is:−s (1 + r ) ≤ pH − t ′which implies(1)/(1)y t pH c r t r −+≤′+−+ (c) As we see from the new collateral constraint, Ricardian equivalence holds, as any shifting oftaxes across periods does not affect the constraint. The consumer makes the same consumptionchoice.3. (a) The bank will be lending so that it will be able to get the loan back in expectation. Thus, the newcollateral constraint isChapter 9 Credit Market Imperfections: Credit Frictions, Financial Crises and Social Security 85−s (1 + r ) ≤ a pHwhich leads to .(1)y t a pH c r −+≤+ This is much like Figure 9.5 in the textbook, simply with a lower collateral value.(b) If the collateral is more likely to be of no value, banks will lend less. Thus, some household willnot be able to borrow as much as they could before, leading for them and in aggregate to areduction of current consumption and an increase in future consumption. Thus we have exactlythe same impact as if we had a reduction in p , as in Figure 9.5 of the textbook.4. Social Security.(a) When the program is first instituted, the current old receive b in benefits and pay nothing.The effect on the current old is as in Figure 9.8 in the text. The current young receive b inbenefits when they are old. This effect is also captured by the shift from BA to FD in thetext’s Figure 9.8. The current young also lend bN to the government in period T and receive(1)r bN + in principal and interest when they are old. In per capita terms, these amounts are/(1)/(1)bN n N b n +=+ and (1)/(1)(1)/(1)r bN n N r b n ++=++ respectively. However, thisborrowing and lending are represented in Figure 9.8 as movements along the budget line.Unless there is a change in the real interest rate, there is no additional shift in the budget line.Therefore, both these generations unambiguously benefit from the program.(b) Once the program is running, it is identical to the pay-as-you-go system in the text. This programbenefits a typical cohort as long as n > r , as is depicted in textbook Figure 9.9. A specialcircumstance applies to the cohort born in period T + 1. These individuals each receive a benefit per capita of b /(1 + r ) in present value terms. However, they pay taxes to support two generations’worth of benefits. They pay taxes to retire the principal and interest on debt incurred in period T . The per capita share of principal and interest on their grandparents’ benefits is equal to(1 + r )b /(1 + n )2. The per capita share of their parents’ benefits is equal to b /(1 + n ). This generation can only benefit if:22(1)(1)1(1)(1)r r n n ++>+++ This requirement is obviously more stringent than .n r >5. Under this regime, disposable income for the young is y , but the price of current consumption is(1 + s ). This implies that the intertemporal budget constraint of the household is now(1)(1)(1)(1)s c c y y b r r r ′′+++=++++ In equibrium, it must be that sc (1 + n ) = b . Thus whether there is going to be a positive income effectis going to depend on n is larger than r . But the is also a substitution effect coming from the change in relative price between c and c ′. This substitution effect has no impact on welfare, though.86 Williamson • Macroeconomics, Fourth Edition6. (a) Consumers born in T are the first ones not to get benefits. The government finances the benefitsof the last generation, bN, with bonds D T. Thus each consumer born in T buys D T/N′ bonds, orb/(1 + n) each. In T +1, the government has to reimburse principal and interest, (1 +r)D T, thuseach old consumer at that time obtains (1 +r)b/(1 +n). This means that for the intertemporalbudget constraint in the figure below, the endowment point is shifted b/(1 + n) to the left and(1 +r)b/(1 +I) up. This is on the same budget constraint as before. However, this household isalso losing the old-age benefits it was expecting, thus the new endowment point shifts anadditional b down. However, this generation does not have to pay, when young, for the benefitsof the previous generation, as they are covered by the debt. Thus, the endowment point shiftsb/(1 +n) to the right. As r> n, the new endowment point is now to the right of the old budgetconstraint, see the figure below, and this household is better of. Essentially, it just the opposite of the situation that made it viable to institute a pay-as-you-go system when n > r. The exact samereasoning applies to all future generations.。
第5章封闭经济下的一时期宏观经济模型一、复习题1．学习封闭经济模型为什么有用？答：封闭经济模型反映的对象是一个单独的国家，与其他国家无关，即没有对外贸易往来。
封闭经济比较容易理解，将一个经济体的经济开放时其经济的大部分性质都不会改变，而且将全世界作为一个整体时封闭经济是一个合理的模型。
同时，可以通过分析在封闭经济中，市场中的消费者和企业是如何互动的，来探讨宏观经济模型的构建方法。
2．政府在一时期封闭经济模型中的作用是什么？答：政府在一时期封闭经济模型中的作用是征税和购买商品。
实践中，政府提供许多不同的产品和服务，包括道路和桥梁、国防、空中交通管制以及教育。
经济学家一般认为，政府在提供公共物品中应发挥特殊作用，因为私人部门难以或不可能提供公共物品。
3．在一时期模型中，政府可以有赤字吗？请解释。
答：在一时期模型中，资金的借、贷行为都无法存在，因此政府无法为其赤字融资，即政府没有赤字。
在预算约束下，政府不能通过借债为其支出筹资，税收收入也不能高于其支出。
政府预算赤字，即G－T≡0。
4．模型中的内生变量有哪些？答：内生变量是由模型本身决定的。
模型中的内生变量包括：C（消费）、N s（劳动供给）、N d（劳动需求）、T（税收）、Y（总产出）和w（市场实际工资）。
5．模型中的外生变量有哪些？答：外生变量是由模型以外的因素决定的。
模型中的外生变量有外生变量G（政府支出）、z（全要素生产率）和K（经济的资本存量）。
6．就这个模型而言，竞争性均衡必须满足哪四个条件？答：竞争性均衡必须满足：（1）典型消费者在他的预算约束下会选择C（消费）和N s（劳动供给），以使其境况尽可能得到改善；（2）典型企业会选择N d（劳动需求），以使其利润最大化；（3）劳动力市场出清，即N d＝N s；（4）政府预算约束得到满足，即G＝T。
7．生产可能性边界的斜率的经济意义是什么？答：生产可能性边界斜率为－MP N，生产可能性边界斜率也被定义为－MRT l，C，MRT l，C为闲暇与消费之间的边际转换率。
Chapter 2MeasurementTextbook Question SolutionsQuestions for Review1. Product, income, and expenditure approaches.2. For each producer, value added is equal to the value of total production minus the cost ofintermediate inputs.3. This identity emphasizes the point that all sales of output provide income somewhere in the economy.The identity also provides two separate ways of measuring total output in the economy.4. GNP is equal to GDP (domestic production) plus net factor payments from abroad. Net factorpayments represent income for domestic residents that are earned from production that takes place in foreign countries.5. GDP provides a reasonable approximation of economic welfare. However, GDP ignores the value ofnonmarket economic activity. GDP also measures only total income without reference to how that income is distributed.6. Measured GDP does not include production in the underground economy, which is difficult toestimate. GDP also measures the value of government spending at its cost of production, which may be greater or less than its true value.7. The largest component is consumption, which represents about 2/3 of GDP.8. Investment is equal to private, domestic expenditure on goods and services (Y − G − NX) minusconsumption. Investment includes residential investment, nonresidential investment, and inventory investment.9. National defense spending represents about 5% of GDP.10. GDP values production at market prices. Real GDP compares different years’ production at a specificset of prices. These prices are those that prevailed in the base year. Real GDP is therefore a weighted average of individual production levels. The weights are determined according to prevailing relative prices in the base year. Because relative prices change over time, comparisons of real GDP across time can differ according to the chosen base year.10 Williamson • Macroeconomics, Fourth Edition11. Chain-weighting directly compares production levels only in adjacent years. The price weights aredetermined by averaging the prices of the individual goods and services over the two adjacent years.12. Real GDP is difficult to measure due to changes over time in relative prices, difficulties in estimatingthe extent of quality changes, and how one estimates the value of newly introduced goods.13. Private saving measures additions to private sector wealth. Government saving measures reductionsin government debt (increases in government wealth). National saving measures additions to national wealth. National saving is equal to private saving plus government saving.14. National wealth is accumulated as increases in the domestic stock of capital (domestic investment)and increases in claims against foreigners (the current account surplus).15. Measured unemployment excludes discouraged workers. Measured unemployment only accountsfor the number of individuals unemployed, without reference to how intensively they search for new jobs.Problems1. Product accounting adds up value added by all producers. The wheat producer has no intermediateinputs and produces 30 million bushels at $3/bu. for $90 million. The bread producer produces100 million loaves at $3.50/loaf for $350 million. The bread producer uses $75 million worth of wheat as an input. Therefore, the bread producer’s value added is $275 million. Total GDP istherefore $90 million + $275 million = $365 million.Expenditure accounting adds up the value of expenditures on final output. Consumers buy100 million loaves at $3.50/loaf for $350 million. The wheat producer adds 5 million bushels of wheat to inventory. Therefore, investment spending is equal to 5 million bushels of wheat valued at $3/bu., which costs $15 million. Total GDP is therefore $350 million + $15 million = $365 million.Chapter 2 Measurement 112. Coal producer, steel producer, and consumers.(a) (i) Product approach: Coal producer produces 15 million tons of coal at $5/ton, which adds$75 million to GDP. The steel producer produces 10 million tons of steel at $20/ton, whichis worth $200 million. The steel producer pays $125 million for 25 million tons of coal at$5/ton. The steel producer’s value added is therefore $75 million. GDP is equal to$75 million + $75 million = $150 million.(ii) Expenditure approach: Consumers buy 8 million tons of steel at $20/ton, so consumption is $160 million. There is no investment and no government spending. Exports are 2 milliontons of steel at $20/ton, which is worth $40 million. Imports are 10 million tons of coal at$5/ton, which is worth $50 million. Net exports are therefore equal to $40 million −$50 million =−$10 million. GDP is therefore equal to $160 million + (−$10 million) =$150 million.(iii) Income approach: The coal producer pays $50 million in wages and the steel producer pays $40 million in wages, so total wages in the economy equal $90 million. The coal producerreceives $75 million in revenue for selling 15 million tons at $15/ton. The coal producerpays $50 million in wages, so the coal producer’s profits are $25 million. The steel producerreceives $200 million in revenue for selling 10 million tons of steel at $20/ton. The steelproducer pays $40 million in wages and pays $125 million for the 25 million tons ofcoal that it needs to produce steel. The steel producer’s profits are therefore equal to$200 million − $40 million − $125 million = $35 million. Total profit income in theeconomy is therefore $25 million + $35 million = $60 million. GDP therefore is equal towage income ($90 million) plus profit income ($60 million). GDP is therefore $150 million.(b) There are no net factor payments from abroad in this example. Therefore, the current accountsurplus is equal to net exports, which is equal to (−$10 million).(c) As originally formulated, GNP is equal to GDP, which is equal to $150 million. Alternatively, ifforeigners receive $25 million in coal industry profits as income, then net factor payments fromabroad are (−$25 million), so GNP is equal to $125 million.3. Wheat and Bread12 Williamson • Macroeconomics, Fourth Edition(a) Product approach: Firm A produces 50,000 bushels of wheat, with no intermediate goods inputs.At $3/bu., the value of Firm A’s production is equal to $150,000. Firm B produces 50,000 loaves of bread at $2/loaf, which is valued at $100,000. Firm B pays $60,000 to firm A for 20,000bushels of wheat, which is an intermediate input. Firm B’s value added is therefore $40,000.GDP is therefore equal to $190,000.(b) Expenditure approach: Consumers buy 50,000 loaves of domestically produced bread at $2/loafand 15,000 loaves of imported bread at $1/loaf. Consumption spending is therefore equal to$100,000 + $15,000 = $115,000. Firm A adds 5,000 bushels of wheat to inventory. Wheat isworth $3/bu., so investment is equal to $15,000. Firm A exports 25,000 bushels of wheat for$3/bu. Exports are $75,000. Consumers import 15,000 loaves of bread at $1/loaf. Imports are$15,000. Net exports are equal to $75,000 − $15,000 = $60,000. There is no governmentspending. GDP is equal to consumption ($115,000) plus investment ($15,000) plus net exports($60,000). GDP is therefore equal to $190,000.(c) Income approach: Firm A pays $50,000 in wages. Firm B pays $20,000 in wages. Total wagesare therefore $70,000. Firm A produces $150,000 worth of wheat and pays $50,000 in wages.Firm A’s profits are $100,000. Firm B produces $100,000 worth of bread. Firm B pays $20,000in wages and pays $60,000 to Firm A for wheat. Firm B’s profits are $100,000 − $20,000 −$60,000 = $20,000. Total profit income in the economy equals $100,000 + $20, 000 = $120,000.Total wage income ($70,000) plus profit income ($120,000) equals $190,000. GDP is therefore$190,000.Chapter 2 Measurement 13 4. Price and quantity data are given as the following.Year 1Good QuantityPrice$1,000Computers 20Bread 10,000$1.00Year 2PriceGood QuantityComputers 25$1,500$1.00Bread 10,000(a) Year 1 nominal GDP 20$1,00010,000$1.00$30,000=×+×=.Year 2 nominal GDP 25$1,50012,000$1.10$50,700=×+×=.With year 1 as the base year, we need to value both years’ production at year 1 prices. In the base year, year 1, real GDP equals nominal GDP equals $30,000. In year 2, we need to value year 2’s=×+×=. The output at year 1 prices. Year 2 real GDP 25$1,00012,000$1.00$37,000percentage change in real GDP equals ($37,000 − $30,000)/$30,000 = 23.33%.We next calculate chain-weighted real GDP. At year 1 prices, the ratio of year 2 real GDP to year1 real GDP equals g1= ($37,000/$30,000) = 1.2333. We must next compute real GDP using year2 prices. Year 2 GDP valued at year 2 prices equals year 2 nominal GDP = $50,700. Year 1 GDPvalued at year 2 prices equals (20 × $1,500 + 10,000 × $1.10) = $41,000. The ratio of year 2 GDP at year 2 prices to year 1 GDP at year 2 prices equals g2=chain-weighted ratio of real GDP in the two years therefore is equal to 1.23496g==.cThe percentage change chain-weighted real GDP from year 1 to year 2 is therefore approximately23.5%.If we (arbitrarily) designate year 1 as the base year, then year 1 chain-weighted GDP equalsnominal GDP equals $30,000. Year 2 chain-weighted real GDP is equal to (1.23496 × $30,000) = $37,048.75.(b) To calculate the implicit GDP deflator, we divide nominal GDP by real GDP, and then multiplyby 100 to express as an index number. With year 1 as the base year, base year nominal GDPequals base year real GDP, so the base year implicit GDP deflator is 100. For the year 2, theimplicit GDP deflator is ($50,700/$37,000) × 100 = 137.0. The percentage change in the deflator is equal to 37.0%.With chain weighting, and the base year set at year 1, the year 1 GDP deflator equals($30,000/$30,000) × 100 = 100. The chain-weighted deflator for year 2 is now equal to($50,700/$37,048.75) × 100 = 136.85. The percentage change in the chain-weighted deflatorequals 36.85%.14 Williamson • Macroeconomics, Fourth Edition(c) We next consider the possibility that year 2 computers are twice as productive as year1 computers. As one possibility, let us define a “computer” as a year 1 computer. In this case,the 25 computers produced in year 2 are the equivalent of 50 year 1 computers. Each year 1computer now sells for $750 in year 2. We now revise the original data as:Year 1PriceGood QuantityYear 1 Computers 20 $1,000Bread 10,000$1.00Year 2PriceGood QuantityYear 1 Computers 50 $750$1.10Bread 12,000First, note that the change in the definition of a “computer” does not affect the calculations ofnominal GDP. We next compute real GDP with year 1 as the base year. Year 2 real GDP in year×+×= The percentage change in real GDP is1 prices is now 50$1,00012,000$1.00$62,000.equal to ($62,000 − $30,000)/$30,000 = 106.7%.We next revise the calculation of chain-weighted real GDP. From above, g1 equals($62,000/$30,000) = 206.67. The value of year 1 GDP at year 2 prices equals $26,000. Therefore, g2 equals ($50,700/$26,000) = 1.95. 200.75. The percentage change chain-weighted real GDPfrom year 1 to year 2 is therefore 100.75%.If we (arbitrarily) designate year 1 as the base year, then year 1 chain-weighted GDP equalsnominal GDP equals $30,000. Year 2 chain-weighted real GDP is equal to (2.0075 × $30,000) =$60,225. The chain-weighted deflator for year 1 is automatically 100. The chain-weighteddeflator for year 2 equals ($50,700/$60,225) × 100 = 84.18. The percentage rate of change of the chain-weighted deflator equals −15.8%.When there is no quality change, the difference between using year 1 as the base year and usingchain weighting is relatively small. Factoring in the increased performance of year 2 computers,the production of computers rises dramatically while its relative price falls. Compared withearlier practices, chain weighting provides a smaller estimate of the increase in production and a smaller estimate of the reduction in prices. This difference is due to the fact that the relative price of the good that increases most in quantity (computers) is much higher in year 1. Therefore, theuse of historical prices puts more weight on the increase in quality-adjusted computer output.Chapter 2 Measurement 15 5. Price and quantity data are given as the following:Year 1GoodQuantity(million lbs.)Price(per lb.)Broccoli 1,500 $0.50 Cauliflower 300 $0.80Year 2GoodQuantity(million lbs.)Price(per lb.)Broccoli 2,400 $0.60Cauliflower 350 $0.85(a) Year 1 nominal GDP = Year 1 real GDP 1,500million$0.50300million$0.80=×+×= $990million.Year 2 nominal GDP 2,400million$0.60350million$0.85$1,730.5million=×+×=Year 2 real GDP 2,400million$0.50350million$0.80$1,450million.=×+×=Year 1 GDP deflator equals 100.Year 2 GDP deflator equals ($1,730.5/$1,450) × 100 = 119.3.The percentage change in the deflator equals 19.3%.(b) Year 1 production (market basket) at year 1 prices equals year 1 nominal GDP = $990 million.The value of the market basket at year 2 prices is equal to 1,500million$0.60300million×+×$0.85= $1,050 million.Year 1 CPI equals 100.Year 2 CPI equals ($1,050/$990) × 100 = 106.1.The percentage change in the CPI equals 6.1%.The relative price of broccoli has gone up. The relative quantity of broccoli has also gone up. The CPI attaches a smaller weight to the price of broccoli, and so the CPI shows less inflation.6. Corn producer, consumers, and government.(a) (i) Product approach: There are no intermediate goods inputs. The corn producer grows30 million bushels of corn. Each bushel of corn is worth $5. Therefore, GDP equals$150 million.(ii) Expenditure approach: Consumers buy 20 million bushels of corn, so consumption equals $100 million. The corn producer adds 5 million bushels to inventory, so investment equals$25 million. The government buys 5 million bushels of corn, so government spendingequals $25 million. GDP equals $150 million.16 Williamson • Macroeconomics, Fourth Edition(iii) Income approach: Wage income is $60 million, paid by the corn producer. The corn producer’s revenue equals $150 million, including the value of its addition to inventory. Additionsto inventory are treated as purchasing one owns output. The corn producer’s costsinclude wages of $60 million and taxes of $20 million. Therefore, profit income equals$150 million − $60 million − $20 million = $70 million. Government income equals taxespaid by the corn producer, which equals $20 million. Therefore, GDP by income equals$60 million + $70 million + $20 million = $150 million.(b) Private disposable income equals GDP ($150 million) plus net factor payments (0) plusgovernment transfers ($5 million is Social Security benefits) plus interest on the government debt ($10 million) minus total taxes ($30 million), which equals $135 million. Private saving equalsprivate disposable income ($135 million) minus consumption ($100 million), which equals$35 million. Government saving equals government tax income ($30 million) minus transferpayments ($5 million) minus interest on the government debt ($10 million) minus governmentspending ($5 million), which equals $10 million. National saving equals private saving($35 million) plus government saving ($10 million), which equals $45 million. The governmentbudget surplus equals government savings ($10 million). Since the budget surplus is positive, the government budget is in surplus. The government deficit is therefore equal to (−$10 million).7. Price controls.Nominal GDP is calculated by measuring output at market prices. In the event of effective pricecontrols, measured prices equal the controlled prices. However, controlled prices reflect an inaccurate measure of scarcity values. Nominal GDP is therefore distorted. In addition to distortions in nominal GDP measures, price controls also inject an inaccuracy in attempts to decompose changes in nominal GDP into movements in real GDP and movements in prices. With price controls, there is typically little or no change in white market prices over time. Alternatively, black market or scarcity value prices typically increase, perhaps dramatically. Measures of prices (in terms of scarcity values)understate inflation. Whenever inflation measures are too low, changes in real GDP overstate the extent of increases in actual production.8. Underground economy.Transactions in underground economy are performed with cash exclusively, to exploit the anonymous nature of currency. Thus, once we have established the amount of currency held abroad, we know the portion of $2,776 that is held domestically. Remove from it what is used for recorded transactions, say by using some estimate of the proportion of transactions using cash and applying this to observed GDP. Finally apply a concept of velocity of money to the remaining amount of cash to obtain the size of the underground economy.9. As for the government sector, the value added in the FIRE sector is difficult to determine with theproduct or the expenditure approach. Thus, this income approach seems most appropriate. However, if wages and profits are not representative of value added, this approach also yields erroneousnumbers. This is especially the case if FIRE income was obtained by hurting costumers, who thereby received no value added. GDP is then overvalued.10. Not all transactions are made with checks or wire transfers. Anything that is paid with cash is notrecorded through Fedwire. Also any transactions with checks between two clients of the same bank do not need to be cleared through Fedwire.Chapter 2 Measurement 17 11. S p − 1 = CA + D(a) By definition:p d S Y C Y NFP TR INT T C =−=+++−−Next, recall that .Y C I G NX =+++ Substitute into the equation above and subtract I to obtain:()()p S I C I G NX NFP INT T C INX NFP G INT TR T CA D−=+++++−−−=++++−=+(b) Private saving, which is not used to finance domestic investment, is either lent to the domesticgovernment to finance its deficit (D ), or is lent to foreigners (CA ).12. Computing capital with the perpetual inventory method.(a) First, use the formula recursively for each year:K 0 = 80K 1 = 0.9 × 80 + 10 = 82K 2 = 0.9 × 82 + 10 = 83.8K 3 = 0.9 × 83.8 + 10 = 85.42K 4 = 0.9 × 85.42 + 10 = 86.88K 5 = 0.9 × 86.88 + 10 = 88.19K 6 = 0.9 × 88.19 + 10 = 89.37K 7 = 0.9 × 89.37 + 10 = 90.43K 8 = 0.9 × 90.43 + 10 = 91.39K 9 = 0.9 × 91.39 + 10 = 92.25K 10 = 0.9 × 92.25 + 10 = 93.03(b) This time, capital stays constant at 100, as the yearly investment corresponds exactly to theamount of capital that is depreciated every year. In (a), we started with a lower level of capital, thus less depreciated than what was invested, as capital kept rising (until it would reach 100).13. Assume the following:10540308010520D INT T G C NFP CA S =======−= (a) 201080110d p Y S CS D C=+=++=++=18 Williamson • Macroeconomics, Fourth Edition (b) 103054015D G TR INT TTR D G INT T =++−=−−+=−−+=(c)208030130S GNP C G GNP S C G =−−=++=++= (d)13010120GDP GNP NFP =−=−= (e)Government Surplus 10g S D ==−=− (f)51015CA NX NFP NX CA NFP =+=−=−−=− (g) 12080301525GDP C I G NX I GDP C G NX =+++=−−−=−−+=14. First some preliminaries. As the unemployment rate is 5% and there are 2.5 million unemployed, itmust be that the labor force is 50 million (2.5/0.05). Thus, the participation rate is 50% (50/100), the labor force 50 million, the number of employed workers 47.5 million (50-2.5), and theemployment/population ratio is 47.5% (47.5/100).。
第3章经济周期的衡量一、复习题1．经济周期的主要特征是什么？答：经济周期的主要特征是：经济周期围绕着实际GDP的趋势波动。
用与现实的实际GDP非常吻合的平滑曲线来表示实际GDP的趋势，这种趋势意味着部分实际GDP可归因于长期增长因素。
其余未分析的，即对趋势的偏离，则用经济周期活动来表示。
表示实际GDP增长趋势的曲线围绕着趋势上下变动，低谷是对趋势的最大负偏离，高峰是对趋势的最大正偏离，从而形成衰退与繁荣的经济周期波动。
2．除持续性外，GDP偏离趋势的三个重要特征是什么？答：GDP偏离趋势的三个重要特征是：（1）实际GDP偏离趋势的时间序列很不稳定。
（2）实际GDP围绕趋势波动的幅度没有规律性。
一些高峰和低谷意味着对趋势的巨大偏离，而另一些高峰和低谷则意味着对趋势的小幅偏离。
（3）实际GDP围绕趋势波动的频率没有规律性。
实际GDP中高峰和低谷之间的时间跨度变化很大。
3．解释预测长期GDP为何困难。
答：预测长期GDP困难的原因：（1）实际GDP围绕趋势波动的幅度没有规律性。
一些高峰和低谷意味着对趋势的巨大偏离，而另一些高峰和低谷则意味着对趋势的小幅偏离。
（2）实际GDP围绕趋势波动的频率没有规律性。
实际GDP中高峰和低谷之间的时间跨度变化很大。
（3）实际GDP偏离趋势的时间序列很不稳定。
总之，实际GDP波动的不稳定使这些波动难以预测，而且不稳定性也使得转折点何时发生难以预测，而波幅和频率的无规律则意味着难以预测衰退和繁荣的强度和时间长短。
4．总体经济变量的联动为何重要？答：尽管实际GDP波动具有不规律的形式，但宏观经济诸变量一起波动的格局显示出了较强的规律性，这些波动格局称为联动。
通过以时间序列图或散点图的形式为两个经济变量偏离其趋势的百分比作图，或通过计算偏离趋势的百分比标准差，就可判别联动。
联动性很重要，因为联动性的规律表明，经济周期是大同小异的。
经济周期的这一性质可能产生分析经济周期的一般理论，这一可能的新理论不同于以往的理论，即：将每一个经济周期都看作是一系列独特条件的结果再进行经济周期的研究。
Macroeconomics, 3e (Williamson)Chapter 5 A Closed-Economy One-Period Macroeconomic Model1) A n economy that has no interaction with the rest of the world is calledA) a n isolated economy.B) a closed economy.C) a parochial economy.D) a rogue nation.Answer: BQuestion Status: P revious Edition2) A n economy that engages in international trade is calledA) a cooperative economy.B) a modern economy.C) a n engaged economy.D) a n open economy.Answer: DQuestion Status: P revious Edition3) G oods and services provided by the government are calledA) g overnment goods.B) p ublic goods.C) f ree goods.D) s ocial goods.Answer: BQuestion Status: P revious Edition4) I n an economic model, an exogenous variable isA) a stand-in for more complicated variables.B) d etermined by the model itself.C) d etermined outside the model.D) a variable that has no effect on the workings of the model.Answer: CQuestion Status: P revious Edition5) I n an economic model, an endogenous variable isA) a stand-in for more complicated variables.B) d etermined by the model itself.C) d etermined outside the model.D) a variable that has no effect on the workings of the model.Answer: BQuestion Status: P revious Edition6) I n a one-period model, government is likely to runA) a deficit but not a surplus.B) a surplus but not a deficit.C) e ither a surplus or a deficit.D) n either a surplus nor a deficit.Answer: DQuestion Status: P revious Edition7) I n a one-period economic model, the government budget constraint requires thatgovernment spendingA) = taxes + transfers.B) = taxes + borrowing.C) > 0.D) = taxes.Answer: DQuestion Status: P revious Edition8) W hich of the following relationships does not hold in the one-period model?A) G=TB) Y=C+GC) Y=zF(K,N)D) π=Y-wN-CAnswer: DQuestion Status: N ew9) F iscal policy refers to a government's choices over itsA) e xpenditures, taxes, transfers, and borrowing.B) e xpenditures, taxes, issuance of money, and borrowing.C) e xpenditures, foreign affairs, issuance of money, and borrowing.D) i ssuance of money, taxes, environmental regulations, and foreign affairs.Answer: AQuestion Status: P revious Edition10) M aking use of an economic model is a process ofA) s olving hundreds of simultaneous equations.B) r unning experiments to determine how changes in the endogenous variables willchange the exogenous variables.C) r unning experiments to determine how changes in the exogenous variables willchange the endogenous variables.D) r esolving inconsistencies in the actions of economic agents.Answer: CQuestion Status: P revious Edition11) A competitive equilibrium is a state of affairs in whichA) m arkets clear, and output is maximized.B) o utput is maximized, and all agents are equally well-off.C) a ll agents are equally well-off and agents are price-takers.D) a gents are price-takers, and markets clear.Answer: DQuestion Status: P revious Edition12) I n a general equilibrium modelA) a ll markets but one clear.B) t here are no fluctuations.C) a ll prices are exogenous.D) a ll prices are endogenous.Answer: DQuestion Status: N ew13) I n a competitive equilibrium all these relationships hold but one. Which one?A) N d= N sB) Y=G+CC) G=TD) w=zAnswer: DQuestion Status: N ew14) I n the one-period competitive model we have been studyingA) b oth consumption and total factor productivity are exogenous.B) c onsumption is exogenous and total factor productivity is endogenous.C) c onsumption is endogenous and total factor productivity is exogenous.D) b oth consumption and total factor productivity are endogenous.Answer: CQuestion Status: P revious Edition15) A relationship that shows the technological possibilities for an economy as a whole is calledaA) p roduction function.B) u tility possibilities frontier.C) p roduction possibilities frontier.D) b udget constraint.Answer: CQuestion Status: P revious Edition16) T he production possibilities frontier in the one-period model is aA) b ehavioral relationship between consumption and leisure.B) b ehavioral relationship between consumption and government spending.C) t echnological relationship between consumption and leisure.D) t echnological relationship between consumption and government spending.Answer: CQuestion Status: P revious Edition17) T he production possibilities frontier representsA) a ll combinations of consumption and leisure for fixed output.B) a ll equally affordable combinations of consumption and leisure for a given wage.C) a ll feasible combinations of consumption and leisure.D) a ll equally liked combinations of consumption and leisure.Answer: CQuestion Status: N ew18) W hich of the following is not a reason for solving the model with a PPF?A) I t merges the household and firm problems into one graph.B) I t is simpler to solve the social planner problem.C) I t highlights the fact that the marginal rate of substitution should equal the marginalrate of transformation.D) I t highlights the fact that firms make no profit in equilibrium.Answer: DQuestion Status: N ew19) T he PPF representsA) a ll possible outcomes for a given wage.B) t he set of feasible outcomes.C) g iven leisure, how much consumption a household wants.D) t he share of consumption in output.Answer: BQuestion Status: N ew20) T he rate at which one good can be converted technologically into another is calledA) t he marginal rate of transformation.B) t he marginal rate of substitution.C) t he marginal product of labor.D) t he rate of conversion.Answer: AQuestion Status: P revious Edition21) P oints on the production possibilities frontier have the property that theyA) a re inherently unattainable.B) s how the maximum amount of leisure that can be consumed for given amounts ofgoods consumed.C) s how the maximum amount of goods that can be consumed for given amounts ofgovernment spending.D) s how the maximum amount of leisure that can be consumed for given amounts ofhours worked.Answer: BQuestion Status: P revious Edition22) A competitive equilibrium has all of the following properties exceptA) M P N= slope of PPF.B) M RS l,C=MRT l,C.C) M RT l,C=MP N.D) M P N=w.Answer: AQuestion Status: P revious Edition23) A competitive equilibrium is Pareto optimal if there is no way to rearrange or to reallocategoods so thatA) a nyone can be made better off.B) n o one can be made worse off.C) s omeone can be made better off without making someone else worse off.D) s omeone can be made better off without making everyone else worse off.Answer: CQuestion Status: P revious Edition24) W hich of the following is not equal to the others in equilibrium?A) t he real wageB) t he marginal rate of substitution between leisure and consumptionC) t he marginal product of laborD) t he price of consumptionAnswer: DQuestion Status: N ew25) A Pareto optimum is a point thatA) a malevolent dictator would choose.B) a cooperative coalition of some altruistic consumers would choose.C) a cooperative coalition of some socially responsible firms would choose.D) a social planner would choose.Answer: DQuestion Status: P revious Edition26) A Pareto optimum requires all of the following exceptA) M P N=-slope of PPF.B) M RS l,C=MRT l,C.C) M RT l,C=MP N.D) M P N=w.Answer: DQuestion Status: P revious Edition27) M uch of the writings of Adam Smith are in close agreement withA) t he necessity of trade restrictions.B) t he first fundamental theorem of welfare economics.C) t he second theorem of welfare economics.D) b oth B and C above.Answer: BQuestion Status: P revious Edition28) T he first fundamental theorem of welfare economics states thatA) u nder certain conditions, a competitive equilibrium is Pareto optimal.B) a competitive equilibrium is always Pareto optimal.C) u nder certain conditions, a Pareto optimum is a competitive equilibrium.D) a Pareto optimum is always a competitive equilibrium.Answer: AQuestion Status: P revious Edition29) T he second fundamental theorem of welfare economics states thatA) u nder certain conditions, a competitive equilibrium is Pareto optimal.B) a competitive equilibrium is always Pareto optimal.C) u nder certain conditions, a Pareto optimum is a competitive equilibrium.D) a Pareto optimum is always a competitive equilibrium.Answer: CQuestion Status: P revious Edition30) T he concept of Pareto optimality is aA) u topian concept.B) u seful concept because it guarantees economic equality.C) u seful concept because it guarantees economic efficiency.D) u seful concept that carefully balances a society's desires for equality and efficiency.Answer: CQuestion Status: P revious Edition31) A competitive equilibrium may fail to be Pareto optimal due to all of the following exceptA) i nequality.B) e xternalities.C) d istorting taxes.D) n on-price-taking firms.Answer: AQuestion Status: P revious Edition32) A n externality is any activity for which an individual firm or consumer does not take intoaccount allA) o f the ramifications of its actions on others.B) a ssociated costs.C) a ssociated benefits.D) a ssociated costs and benefits.Answer: DQuestion Status: P revious Edition33) T he presence of a distorting tax on wage income can result inA) M P N<MRT l,C.B) M RT l,C<MRS l,C.C) M P N<w.D) M RS l,C<MP N.Answer: DQuestion Status: P revious Edition34) R elative to the social optimum, monopoly power directly leads toA) u nderproduction.B) o verproduction.C) t oo much leisure.D) t oo little leisure.Answer: AQuestion Status: P revious Edition35) A n increase in government spending shifts the PPFA) u pward, but does not change its slope.B) u pward, and also changes its slope.C) d ownward, but does not change its slope.D) d ownward, and also changes its slope.Answer: CQuestion Status: P revious Edition36) T he experience of the U.S. economy during World War II confirms the prediction that adramatic increase in government spending is likely toA) i ncrease both real GDP and consumption.B) i ncrease real GDP and decrease consumption.C) d ecrease real GDP and increase consumption.D) d ecrease both real GDP and consumption.Answer: BQuestion Status: P revious Edition37) A n increase in government spendingA) i ncreases consumption, increases hours worked, and increases the real wage.B) r educes consumption, increases hours worked, and increases the real wage.C) r educes consumption, increases hours worked, and reduces the real wage.D) r educes consumption, reduces hours worked, and reduces the real wage.Answer: CQuestion Status: P revious Edition38) A n increase in government spendingA) i ncreases consumption and output.B) i ncreases consumption, decreases output.C) d ecreases consumption, increases output.D) d ecreases consumption and output.Answer: CQuestion Status: N ew39) C hanges in government spending are not likely causes of business cycles becausegovernment spending induced business cycles would counterfactually predictA) c ountercyclical real wages.B) p rocyclical real wages.C) c ountercyclical employment.D) p rocyclical employment.Answer: AQuestion Status: P revious Edition40) C hanges in government spending are not likely causes of business cycles becausegovernment spending induced business cycles would counterfactually predictA) c ountercyclical consumption.B) p rocyclical consumption.C) c ountercyclical employment.D) p rocyclical employment.Answer: AQuestion Status: P revious Edition41) W hich feature of the business cycle does the one-period model replicate with shocks togovernment expenditures?A) p rocyclical employmentB) p rocyclical consumptionC) p rocyclical real wagesD) c ountercyclical pricesAnswer: AQuestion Status: N ew42) A n increase in total factor productivity shifts the PPFA) u pward, but does not change its slope.B) u pward, and also changes its slope.C) d ownward, but does not change its slope.D) d ownward, and also changes its slope.Answer: BQuestion Status: P revious Edition43) A n increase in total factor productivityA) i ncreases consumption, increases output, and increases the real wage.B) r educes consumption, increases output, and increases the real wage.C) r educes consumption, increases output and reduces the real wage.D) r educes consumption, reduces output, and reduces the real wage.Answer: AQuestion Status: P revious Edition44) W hich of the following is wrong with respect to an increase in total factor productivity?A) H ouseholds are better off.B) C onsumption is up.C) T he real wage is down.D) O utput is up.Answer: CQuestion Status: N ew45) I n response to an increase in total factor productivityA) b oth the substitution effect and the income effect suggest that hours worked shouldincrease.B) t he substitution effect suggests that hours worked should increase, while the incomeeffect suggests that hours worked should decrease.C) t he substitution effect suggests that hours worked should decrease, while the incomeeffect suggests that hours worked should increase.D) b oth the substitution effect and the income effect suggest that hours worked shoulddecrease.Answer: BQuestion Status: P revious Edition46) C hanges in total factor productivity are plausible causes of business cycles becauseproductivity-induced business cycles correctly predictA) r eal wages and total hours must be procyclical.B) r eal wages and consumption must be procyclical.C) t otal hours worked and consumption must be procyclical.D) c onsumption and government spending must be procyclical.Answer: BQuestion Status: P revious Edition47) C hanges in total factor productivity are plausible causes of business cycles becauseA) o f the welfare theorems.B) t he U.S. government is following supply-side economic policy.C) t he model matches many stylized facts.D) p rices are countercyclical.Answer: CQuestion Status: N ew48) R eal business cycle theory argues that the primary cause of business cycles is fluctuations inA) p references.B) g overnment spending.C) t he importance of externalities.D) t otal factor productivity.Answer: DQuestion Status: P revious Edition49) J ust prior to the four most recent U.S. recessions, there has been aA) s ignificant contraction of the money supply.B) l arge decrease in government spending.C) l arge increase in the relative price of food.D) s ignificant increase in the relative price of energy.Answer: DQuestion Status: P revious Edition50) I f the government replaces a lump sum tax with a proportional labor income tax, thenA) e mployment and output increase.B) e mployment increases and output decreases.C) e mployment decreases and output increases.D) e mployment and output decrease.Answer: DQuestion Status: N ew51) P roportional income taxation is distorting becauseA) p eople do all they can to avoid paying taxes.B) t he competitive equilibrium is not Pareto optimal.C) f irms do all they can to avoid paying taxes.D) t he government budget constraint does not hold.Answer: BQuestion Status: N ew52) W ith a linear production function in labor only, which of the following must be true?A) T he representative household works as much as possible.B) T he representative firm makes large profits.C) T he real wage equals total factor productivity.D) T he marginal product of labor exceeds the real wage.Answer: CQuestion Status: N ew53) H ow does an increase in the proportional labor income tax modify the budget constraint?A) a parallel move upB) a parallel move downC) a tilting upD) a tilting downAnswer: DQuestion Status: N ew54) A t the competitive equilibrium with a positive proportional labor income taxA) t he real wage after tax exceeds the marginal product of labor.B) t he real wage after tax equals the marginal product of labor.C) t he real wage after tax is lower than the marginal product of labor.D) W e cannot say.Answer: CQuestion Status: N ew55) A t the competitive equilibrium with a positive proportional labor income taxA) t he real wage before tax exceeds the marginal product of labor.B) t he real wage before tax equals the marginal product of labor.C) t he real wage before tax is lower than the marginal product of labor.D) W e cannot say.Answer: BQuestion Status: N ew56) T he tax base isA) t he average tax rate.B) t he tax rate for the base year.C) t he object being taxed.D) t he lowest tax rate.Answer: CQuestion Status: N ew57) W hen the tax rate increases, the tax revenueA) a lways increases.B) d oes not change.C) a lways decreases.D) m ay increase or decrease.Answer: DQuestion Status: N ew58) T he Laffer curve is a curve showingA) o utput as a function of the tax rate.B) t ax revenue as a function of the tax rate.C) g overnment expenses as a function of how liberal the government is.D) t he tax rate as a function of government expenses.Answer: BQuestion Status: N ew59) S upply-side economists argue thatA) o ne should get rid of all taxes.B) t ax rates should not be progressive.C) i ncreasing tax rates always hurts tax revenue.D) o ne can increase tax revenue by decreasing the tax rate.Answer: DQuestion Status: N ew60) I n a competitive equilibrium with a Laffer curve, there are two equilibria that differ in theirA) t ax revenue.B) t otal factor productivity.C) o utput.D) m arginal tax rate.Answer: CQuestion Status: N ew。
1 / 37第1章 导 论1.1 复习笔记一、宏观经济学1．宏观经济学的研究对象宏观经济学的研究对象是众多经济主体的行为。
它关注的是消费者和企业的总体行为、政府的行为、单个国家的经济活动总水平、各国间的经济影响，以及财政政策和货币政策的效应。
2．宏观经济学与微观经济学的联系与区别（1）联系微观经济学家与宏观经济学家都在使用非常相似的研究工具。
宏观经济学家用来描述消费者与企业的行为、目标与约束，以及他们之间如何相互影响的经济模型，是根据微观经济学原理建立起来的，而且在分析这些模型和拟合数据时通常都用微观经济学家所用的方法。
2 / 37（2）区别宏观经济学的研究对象有别于微观经济学，宏观经济学侧重于总量研究，强调的问题主要是长期增长和经济周期。
微观经济学主要针对单个消费者或者企业的行为选择。
二、国内生产总值、经济增长与经济周期1．国内生产总值（gross domestic product ，GDP ）国内生产总值是一国在某一特定时期在境内生产的产品和服务的数量。
GDP 也表示那些对国内产出作出贡献的人挣得的收入总量。
实际GDP 是针对通货膨胀进行调整后的总产出衡量指标。
2．经济增长（long-run growth ）经济增长率是一个国家当年国内生产总值对比往年的增长率。
经济正增长一般被认为是整体经济景气的表现。
长期增长是指一国长期的生产能力和平均生活水平的提高。
3．经济周期（business cycles ）经济周期是指总体经济的短期上下波动，或经济的繁荣与衰退。
3 / 37三、宏观经济模型1．宏观经济模型及其假设宏观经济模型是用来解释长期经济增长、经济周期存在的原因、以及经济政策在宏观经济中应发挥的作用的模型。
确切的说，宏观经济模型的基本构造是用来描述下列特征的：（1）经济中相互影响的消费者与企业。
（2）消费者希望消费的一组商品。
（3）消费者对商品的偏好。
（4）企业生产商品可采用的技术。
（5）可利用的资源。
威廉森《宏观经济学》课后习题（衡量）【圣才出品】第2章衡量⼀、复习题1．衡量GDP的三种⽅法是什么？答：衡量GDP的三种⽅法包括⽣产法、收⼊法和⽀出法。
（1）⽣产法⽣产法也被称作增加值法，是将经济中全部⽣产单位⽣产的产品和服务的增加值加总来计算GDP。
为了⽤⽣产法核算GDP，⾸先将经济体⽣产的所有产品和服务价值相加，然后减去为实现总增加值⽽投⼊⽣产的所有中间产品的价值，以避免重复计算。
（2）⽀出法就⽀出法⽽⾔，GDP是指⽤于经济体⽣产最终产品和最终服务⽅⾯的总⽀出。
不计算⽤于中间产品的⽀出。
总⽀出的计算公式是：总⽀出＝C＋I＋G＋NX。
式中，C为消费⽀出；I为投资⽀出；G为政府⽀出；NX为净出⼝，即出⼝产品和服务的总额减去其进⼝的总额。
（3）收⼊法⽤收⼊法计算GDP，要将各经济主体因参与⽣产⽽获得的全部收⼊加总。
收⼊包括企业实现的利润。
收⼊包括雇员报酬（⼯资、薪⾦和津贴）、业主（⾃营企业的所有者）收⼊、租⾦收⼊、公司利润、净利息、企业间接税（企业缴纳的⼯资税和销售税）和折旧（固定资本损耗）。
折旧是在考虑的时期内⽣产性固定资本（⼯⼚和设备）损耗的价值。
由于计算利润时剔除了折旧，因⽽在计算GDP时需要将此再加进来。
2．解释增加值的概念。
答：⽤⽣产法核算GDP，⾸先应将经济体⽣产的所有产品和服务价值相加，然后减去为实现总增加值⽽投⼊⽣产的所有中间产品的价值，最终得到总增加值。
（1）从私⼈⽣产的⾓度⽽⾔，即对于每个⽣产商，增加值等于总⽣产价值减去中间投⼊的成本。
以饭店服务为例，不应把提供饭店服务过程中投⼊的椰⼦价值算作GDP的⼀部分，⽽是应作为中间产品从GDP中减去，进⽽得到⽣产增加值。
（2）对政府⽣产⽽⾔，由于政府提供的⽣产⼀般⽆法按市场价格销售，以防务的提供为例，其对GDP的贡献就等于提供防务时所需要的劳动⼒的投⼊成本，由此⽽得到提供防务时的国民⽣产增加值。
3．收⼊-⽀出恒等式为什么重要？答：收⼊⽀出恒等式重要的原因：（1）收⼊⽀出恒等式提供了两种单独衡量经济总产出的⽅式，即收⼊法和⽀出法。
Chapter 5A Closed-Economy One-PeriodMacroeconomic ModelTextbook Question SolutionsQuestions for Review1. A closed economy is easier to work with. Opening the economy does not change most of theproperties of an economy. The closed economy is the correct model for the world as a whole.2. Government levies taxes and purchases consumption goods.3. In a one-period model, there can be no borrowing or lending. There is therefore no way to finance agovernment deficit.4. Endogenous variables: C , N s , N d , T , Y , and w .5. Exogenous variables: G , z , K .6. The representative consumer chooses C and N s to maximize utility.The representative firm chooses N d to maximize profits.Market-clearing: .s d N N N ==Government budget constraint: T = G .7. The slope of the production possibilities frontier is equal to .N MP − The slope of the productionpossibilities frontier is also identified as ,,l C MRT − where ,l C MRT is identified as the marginal rate oftransformation between leisure and consumption.8. The competitive equilibrium is Pareto optimal because it lies at a tangency point between theproduction possibilities frontier and a representative consumer’s indifference curve.9. The first theorem: A competitive equilibrium can be Pareto optimal. This theorem assures us that thecompetitive equilibrium is a good outcome. The second theorem: A Pareto optimum is a competitive equilibrium. This theorem allows us to directly analyze Pareto optima with the assurance that these points are also competitive equilibriums. The second theorem is useful because Pareto Optimaare often easier to work with than competitive equilibriums.Chapter 5 A Closed-Economy One-Period Macroeconomic Model 43 10. Externalities, noncompetitive behavior, and distorting taxes.11. , ,, , and .G Y C N l w ↑⇒↑↓↑↓↓ 12. Government competes with the private sector in buying goods. An increase in government spendingimplies a negative wealth effect, which results in lower consumption.13. , , and .z Y C w ↑⇒↑↑↑ The sign of the effects on N and l are ambiguous.14. The substitution effect of an increase in z is that the representative consumer works more hours. Theincome effect of an increase in z is that the representative household works more hours. The sign of the net effect is ambiguous.15. A distorting tax makes that households equalize their marginal rate of substitution between leisureand consumption to the after tax wage, which is different from the before tax wage that firms equalize their marginal rate of transformation to. Thus, one cannot achieve the Pareto optimum where thesame wage (before tax) is equal to both marginal rates above.16. The Laffer curve takes into account that higher proportional tax rates give incentives to households towork less. While tax revenue increases with the tax rate for a given tax base, that tax base is reduced by the tax rate.17. When the income tax rate falls, households are willing to supply additional labor more in suchquantities that the tax base increases more than what the tax rate decreases, thus increasing taxrevenue.44 Williamson • Macroeconomics, Fourth EditionProblems1. Although we often think about the negative externalities of congestion and pollution in cities, theremay also be some positive externalities. A concentrated population is better able to support the arts and professional sports; cities typically have a greater variety of good restaurants, etc. Perhaps a more basic issue is that there may be some increasing returns to scale at low output levels that makeindustrial production more costly in small towns. There may also be externalities in production in being located close to other producers. One example would be the financial industry in financialcenters like New York, London, Tokyo, etc. Another example would be large city medical centers that enhance coordination between primary physicians and specialists.One market test of whether productivity is higher in cities would be to look at the wages in cities versus the wages in smaller towns and rural areas. Wages are often higher in cities for individuals of comparable skills. Market efficiency suggests that the higher wages be reflective of a higher marginal product of labor, and that the higher wages compensate those choosing to live in cities for thenegative externalities that they face.2. In a one period model, taxes must be exactly equal to government spending. A reduction in taxes istherefore equivalent to a reduction in government spending. The result is exactly opposite of the case of an increase in government spending that is presented in the text. A reduction in governmentspending induces a pure income effect that induces the consumer to consume more and work less. At lower employment, the equilibrium real wage is higher because the marginal product of labor rises when employment falls. Output falls, consumption rises, employment falls and the real wage rises. 3. The only impact effect of this disturbance is to lower the capital stock. Therefore, the productionpossibility frontier shifts down and the marginal product of labor falls (PPF is flatter).(a) The reduction in the capital stock is depicted in the figure below. The economy starts at point Aon PPF1. The reduction in the capital stock shifts the production possibilities frontier to PPF2.Because PPF2 is flatter, there is a substitution effect that moves the consumer to point D. Theconsumer consumes less of the consumption good and consumes more leisure. Less leisure alsomeans that the consumer works more. Because the production possibilities frontier shifts down,there is also an income effect. The income effect implies less consumption and less leisure (more work). On net, consumption must fall, but leisure could decrease, remain the same, or increase,depending on the relative strengths of the income and substitution effect. The real wage must also fall. To see this, we must remember that, in equilibrium, the real wage must equal the marginalrate of substitution. The substitution effect implies a lower marginal rate of substitution. Theincome effect is a parallel shift in the production possibilities frontier. As the income effectincreases the amount of employment, marginal product of labor must fall from point D topoint B. This reinforces the reduction in the marginal rate of substitution from point A to point D.Chapter 5 A Closed-Economy One-Period Macroeconomic Model 45(b) Changes in the capital stock are not likely candidates for the source of the typical business cycle.While it is easy to construct examples of precipitous declines in capital, it is more difficult toimagine sudden increases in the capital stock. The capital stock usually trends upward, and thisupward trend is important for economic growth. However, the amount of new capital generatedby a higher level of investment over the course of a few quarters, of a few years, is very small incomparison to the existing stock of capital. On the other hand, a natural disaster that decreasesthe stock of capital implies lower output and consumption, and also implies lower real wages,which are all features of the typical business cycle contraction.4. Government Productivity. First consider the benchmark case in which 1,z = and there is no effect ofchanges in z on government activities. Now suppose that z increases. This case of an increase in z is depicted in the figure below. The original production possibilities frontier is labeled PPF 1 and the competitive equilibrium is at point A. If the increase in z only affects the economy through thechange in (,),zF K N then the new production possibilities frontier is PPF 2. The diagram shows a case in which the income and substitution effects on leisure exactly cancel out, and the economymoves to point B. The equation for the production possibilities frontier is (,).C zF K h l T =−− In the benchmark case, T G = and so we have (,).C zF K h l G =−− For this problem, /,T G z = and so the production possibilities frontier is given by (,)/.C zF K h l G z =−− When 1,z = the two PPFscoincide. When z increases, the vertical intercept of the PPF increases by /.G z Δ Therefore, the new PPF is PPF 3 in the figure below. The competitive equilibrium is at point C . There is an additional income effect that provides an additional increase in equilibrium consumption, and a reinforcedincome effect that tend to make leisure increase. Therefore, relative to the benchmark case, there is a larger increase in consumption, and either a smaller decrease in leisure or a larger increase in leisure.46 Williamson • Macroeconomics, Fourth Edition5. Change in preferences.(a) At the margin, the consumer decides that leisure is more preferred to consumption. That is, theconsumer now requires a bigger increase in consumption to willingly work more (consume lessleisure). In more intuitive language, the consumer is lazier.(b) To work out the effects of this change in tastes, we refer to the figure below. The productionpossibility frontier in this example is unchanged. The consumer now picks a new point at which one of the flatter indifference curves is tangent to the production possibilities frontier. That is,equilibrium will shift from point A to point B. Consumption falls and leisure rises. Therefore, the consumer works less and produces less. Because employment has fallen, it also must be the case that the real wage increases.Chapter 5 A Closed-Economy One-Period Macroeconomic Model 47(c) This disturbance, which some might characterize as a contagious outbreak of laziness, wouldhave the appearance of a recession, as output and employment both fall. The consequentreduction in consumption is also consistent with a typical recession. However, in this case thereal wage would rise, which is inconsistent with the business cycle facts. Therefore, this type ofpreference change is not a cause of recessions.6. (a) With conscription, the government reduces the time available for market work from h to h −a.The consumption given to conscript is not relevant, as it is taxed away. This only a transfer thatdoes not impact the production capacity of the economy.48 Williamson • Macroeconomics, Fourth EditionThe production possibilities frontier PPF1 moves to the left (PPF2), such that it originates at(−G, h−a). The equilibrium moves from A to B. The consequence is a drop in consumptionfrom C1 to C2, as well as in leisure from l1 to l2. As there is no change in G, aggregate outputdecreases as well. All this is the result of the economy having less labor available for production.(b) To finance the army, the government needs to levy new taxes to cover wages of soldiers, butreturns this in consumption. This is purely redistributive and thus does not change G, and thesame outcome as in (a) is obtained.(c) Both results highlight how military service drags the productive capacity of a country down. Butthe financing of this activity does not matter, all that is relevant is the loss of resources (in thiscase time).7. Production-enhancing aspects of government spending.(a) The increase in government spending in this example has two separate effects on the productionpossibilities frontier. First, the increase in government spending from G1 to G2 implies a paralleldownward shift in the production possibilities frontier. Second, the productive nature ofgovernment spending is equivalent to an increase in total factor productivity that shifts theproduction possibilities frontier upward and increases its slope. The figure below draws theoriginal production possibilities frontier as PPF1 and the new production possibilities frontier asPPF2. If the production-enhancing aspects of the increase in government spending are largeenough, representative consumer utility could rise, as in this figure.(b) There are three effects at work in this example. First, there is a negative income effect from theincrease in taxes needed to pay for the increased government spending. This effect tends to lower both consumption and leisure. Second, there is a substitution effect due to the productive effect of the increase in G, which is drawn as the movement from point A to point D. This effect tends toincrease both consumption and leisure. Third, there is a positive income effect from the increasein G on productivity. This effect tends to increase both consumption and leisure. In the figureabove, the movement from point D to point B is the net effect of the two income effects. Ingeneral, consumption may rise or fall, and leisure may rise or fall. The overall effect on output is the same as in any increase in total factor productivity. Output surely rises.Chapter 5 A Closed-Economy One-Period Macroeconomic Model 49 8. (a) If households dedicate a hours to education today, it reduces the hours available for leisure andwork to h−a. The PPF has to start form point (−G, h−a). Graphically, this corresponds to thefigure in the answer of question 6(b). The consequence is thus a reduction in consumption,leisure, employment, aggregate output, but an increase in the real wage.(b) In the future, workers will be more efficient, which corresponds to an increase in total factorproductivity. Thus we have the case described in Figure 5.9 of the textbook. There is an increasein future consumption, aggregate output and the real wage. Changes in employment and leisureare ambiguous.(c) An increase in education leads to an immediate loss in welfare, as both leisure and consumptionare reduced. But this is compensated by an increase in future consumption, and possibly ofleisure, too. Whether this is worth doing depends on the preferences of households over currentand future utility.9. The fact that government spending make firms more productive is similar to adding G to theproduction function. There are now two effects to an increase in government expenses: the standard crowding out of consumption, and now also an efficiency effect on production.(a) The figure below illustrates a particular situation where the welfare of the household is improved,as illustrated by a shift to the north-east of the indifference curve. The equilibrium shifts fromA toB as the PPF is lowered by the additional government expenses but is also getting steeperthanks to the same government expenses.(b) From previous results, we know that output increases with the increase in government expenses.This is now reinforced as G increases production efficiency. Regarding consumption and leisure, without this new effect, we obtained that an increase in G lead to a negative income effect andthus to decreases in both consumption and leisure. But as the real wage went down, there wasalso a substitution effect leading to an additional decrease in consumption and increase in leisure.The new effect on the production function adds opposite effects: a positive income effect and awage increase, thus possibly reversing, or not, anything that was concluded without the impact ofG on production.50 Williamson • Macroeconomics, Fourth Edition10. We need to analyze each case separately. Start with the good equilibrium. As government expensesincrease, more tax revenue needs to be raised, and thus the tax rate needs to be increased. As shown in the figure below, this tilts down the linear PPF. The new equilibrium leads to a lower indifferencecurve. This leads to a negative income effect and a lower wage (remember, it is z(1 − t)), thus asubstitution effect. The income effect lowers consumption and leisure, the substitution effectdecreases consumption and increases leisure. All in all, consumption is lower and leisure is higher, as we know that the substitution effect dominates the income effect. This means that the labor supply is reduced, and thus equilibrium labor and output.The story is different in the bad equilibrium. To increase tax revenue, one needs to reduce the tax rate.Then all the changes discussed above are exactly in the opposite direction.11. We know from previous analysis that an improvement in total factor productivity pushes up the PPF,and thus leads to an increase in consumption, a decrease in leisure, and thus an increase in thequantity of labor supplied. This increases the tax base, and thus allows a reduced tax rate to achieve the same tax revenue, or in other words, it pushes the left portion of the Laffer curve to the left. The reduction in the tax rate has then a further impact on the variables of interest: as we saw in question 7, first part with a reversal of all signs: consumption increases even more and leisure decrease yet more, leading to an even higher quantity of labor. All in all, as both labor and total factor productivityincrease, output increases.。
