中级微观经济学题库及参考答案.doc

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中级微观经济学45道题（含答案）

中级微观经济学45道题（含答案）中级微观经济学期末考试复习题（版权归13企业管理班所有，翻版必究，哈哈！）1.实现委托代理最优合约设计的两个约束条件是什么、答：⼀种是代理⼈的个⼈理性约束，即委托⼈得保证让代理⼈不跳槽，安于经理岗位。

另⼀种是对代理⼈的激励相容约束，即让代理⼈⾃⼰去选择⾏动值a，使其期望的边际效⽤值达到最⼤。

2、为何需求的价格弹性⼤于1时，降价能增加收益，⽽需求的价格弹性⼩于1时，涨价能增加收益，请给出数学证明。

答：需求的价格弹性公式为：由公式可知，当|e|>1，即富于弹性时，MR<0，边际收益为负，即提⾼价格，收益降低，相反，降低价格则收益升⾼。

当|e|<1，即缺乏弹性时，MR>0，边际收益为正，即提⾼价格，收益升⾼，相反，降低价格，收益变少。

3.简述公共产品与私⼈产品的差异。

（微观经济学⼗⼋讲P352）答：公共品是指由公共部门提供⽤来满⾜社会公共需要的商品和服务。

公共品具有不可分割性、⾮竞争性和⾮排他性。

但是必须明确并不是全部的公共品都应由公共部门提供。

私⼈品是指那些具有效⽤上的可分割性，消费上的竞争性和受益上的排他性的产品。

公共品和私⼈品的区别在于，公共品是可以让⼀群⼈同时消费的物品，⽽私⼈品在任何时候只能为⼀个使⽤者提供效⽤。

%4、毕加索油画的供给价格弹性是多少，为什么答：弹性0，因为供给的价格弹性反映价格变动对供给数量变动的影响。

毕加索的油画是唯⼀的，因此，不管价格如何变动，供给为1，即供给不随价格变动⽽变动，弹性为0。

5、完全竞争市场条件下，为什么⾏业中所有⼚商的经济利润在长期均衡时都会为零这是否意味着⼚商的⽣产变得没有意义西⽅经济学中所谓长期均衡时利润为零，是指经济利润为零，并不是会计利润为零。

所谓经济利润，通常也叫超额利润，就是⼀个⼚商赚取了较之⼀般利润⽔平更⾼的利润。

之所以如此，这是因为，在西⽅经济学理论上，会计利润被计⼊⼚商投⼊⾃有要素所应获得的报酬，是产品的隐含成本。

中级微观经济学习题及部分答案

中级微观经济学习题及部分答案一、单项选择题（每题0.5分，共15分，将正确答案填入答题纸上）1.有下列因素除哪一种外都会使需求曲线移动？（B）a消费者收入变化；b商品价格变化；c消费者偏好变化；d其他相关商品价格变化。

2.假定某耐用消费品的需求函数Qd=400-5P时的均衡价格为50，当需求函数变为Qd=600-5P时，（供给不变）均衡价格将（B）a低于50b高于50c等于50d不变3.下列命题中哪个是规范经济学的命题?(A)a.征税对中等收入家庭是不公平的c.1982年8月政府把贴现率降到10％b.1981年失业率超过9％d.社会保险税的课税依据现已超过30000美元4.当供求力量自由作用时，一次谷物歉收通过什么显示在市场上？（B）a.政府规定的购买量限制b.谷物价格上涨c.劝说人们减少购买量的广告d.谷物贸易量的增加5.某月内，X商品的替代品的价格上升和互补品的价格上升，分别引起X商品的需求变动量为50单位和80单位，则在它们共同作用下该月X商品需求数量：（B）。

a.增加30单位b.减少30单位c.增加130单位d.减少130单位6.在完全竞争市场中，（C）。

a.消费者是价格接受者，而企业不是b.消费者和企业都不是价格接受者c.消费者和企业都是价格接受者d.企业是价格接受者，而消费者不是/doc/3914130.html,C曲线（A）。

a.当LMC＜LAC时下降，而当LMC＞LAC时上升b.随LMC曲线下降而下降c．随LMC曲线上升而上升 d.通过LMC曲线的最低点8．一个企业在以下哪种情况下应该关闭？（A）a.P＜A VCb.P＜SACc.发生亏损时d.SMC＞MR9.寡头垄断和垄断竞争之间的主要区别是（C）。

a.厂商的广告开支不同b.非价格竞争的种类不同c.厂商之间相互影响的程度不同d.以上都不对10.短期内，完全竞争厂商只能通过对（D）调整来实现最大利润。

a.生产规模b.价格c.全部生产要素d.产量11.不完全竞争市场中出现低效率的资源配置是因为产品价格（A）边际成本a．大于b．小于c．等于d．大于或等于12．当市场处于长期均衡状态时，向右下方倾斜的需求曲线相切于长期平均成本的最低点的左边，产品的价格等于生产的平均成本，产品产量较高但存在多余的生产能力，则该市场属于下列哪一类(B)。

中级微观经济学习题及答案

中级微观经济学习题及答案ANSWERS1 The Market1. Suppose that there were 25 people who had a reservation price of $500, and the 26th person had a reservation price of $200. What would the demand curve look like?1.1. It would be constant at $500 for 25 apartments and then drop to $200.2. In the above example, what would the equilibrium price be if there were 24 apartments to rent? What if there were 26 apartments to rent?What if there were 25 apartments to rent?1.2. In the ?rst case, $500, and in the second case, $200. In the third case, the equilibrium price would be any price between $200 and $500.3. If people have di?erent reservation prices, why does the market demand curve slope down?1.3. Because if we want to rent one more apartment, we have to o?er a lower price. The number of people who have reservation prices greater than p must always increase as p decreases.4. In the text we assumed that the condominium purchasers came from the inner-ring people—people who were already rentingapartments. What would happen to the price of inner-ring apartments if all of the condominium purchasers were outer-ring people—the people who were not currently renting apartments in the inner ring? 1.4. The price of apartments in the inner ring would go up since demand for apartments would not change but supply would decrease.5. Suppose now that the condominium purchasers were all inner-ring people, but that each condominium was constructed from two apartments. What would happen to the price of apartments?1.5. The price of apartments in the inner ring would rise.6. What do you suppose the e?ect of a tax would be on the number of apartments that would be built in the long run?1.6. A tax would undoubtedly reduce the number of apartments supplied in the long run.7. Suppose the demand curve is D(p) = 100?2p. What price would the monopolist set if he had 60 apartments? How many would he rent? What price would he set if he had 40 apartments? How many would he rent?1.7. He would set a price of 25 and rent 50 apartments. In the second case he would rent all 40 apartments at the maximum price the marketwould bear. This would be given by the solution to D(p) = 100?2p = 40, which is p? = 30.8. If our model of rent control allowed for unrestricted subletting, who would end up getting apartments in the inner circle? Would the outcome be Pareto e?cient?1.8. Everyone who had a reservation price higher than the equilibrium price in the competitive market, so that the ?nal outcome would be Pareto e?cient.(Of course in the long run there would probably be fewer new apartments built, which would lead to another kind of ine?ciency.)2 Budget Constraint1. Originally the consumer faces the budget line p1x1 + p2x2 = m. Then the price of good 1 doubles, the price of good 2 becomes 8 times larger, and income becomes 4 times larger. Write down an equation for the new budget line in terms of the original prices and income.2.1. The new budget line is given by 2p1x1 +8p2x2 =4m.2. What happens to the budget line if the price of good 2 increases, but the price of good 1 and income remain constant? 2.2. The vertical intercept (axis) decreases and the horizontalx2intercept (axis) stays the same. Thus the budget line becomes ?atter.x13. If the price of good 1 doubles and the price of good 2 triples, does the budget line become ?atter or steeper?2.3. Flatter. The slope is ?2/3.p1p24. What is the de?nition of a numeraire good?2.4. A good whose price has been set to 1; all other goods’ prices are measured relative to the numeraire good’s price.5. Suppose that the government puts a tax of 15 cents a gallon on gasoline and then later decides to put a subsidy on gasoline at a rate of 7 cents a gallon. What net tax is this combination equivalent to?2.5. A tax of 8 cents a gallon.6. Suppose that a budget equation is given by += m. Thep1x1p2x2 government decides to impose a lump-sum tax of u, a quantity tax on good 1 of t, and a quantity subsidy on good 2 of s. What is the formula for the new budget line?2.6. (+ t)+(?s)= m?u.p1x1p2x27. If the income of the consumer increases and one of the prices decreases at the same time, will the consumer necessarily be at leastas well-o??2.7. Yes, since all of the bundles the consumer could a?ord before are a?ordable at the new prices and income.3 Preferences1. If we observe a consumer choosing (,) when (,) is availablex1x2y1y2one time, are we justi?ed in concluding that (,)>(,)?x1x2y1y23.1. No. It might be that the consumer was indi?erent between the two bundles. All we are justi?ed in concluding is that (,)> (,).x1x2y1y22. Consider a group of people A, B, C and the relation “at least as tall as,” as in “A is at least as tall as B.” Is this relation transitive? Is it complete?3.2. Yes to both.3. Take the same group of people and consider the relation “strictly taller than.” Is this relation transitive? Is it re?exive? Is it complete? 3.3. It is transitive, but it is not complete—two people might be the same height. It is not re?exive since it is false that a person is strictly taller than himself.4. A college football coach says that given any two linemen A and B, he always prefers the one who is bigger and faster. Is this preferencerelation transitive? Is it complete?3.4. It is transitive, but not complete. What if A were bigger but slower than B? Which one would he prefer?5. Can an indi?erence curve cross itself? For example, could Figure 3.2 depict a single indi?erence curve?3.5. Yes. An indi?erence curve can cross itself, it just can’t cross another distinct indi?erence curve.6. Could Figure 3.2 be a single indi?erence curve if preferences are monotonic?3.6. No, because there are bundles on the indi?erence curve that have strictly more of both goods than other bundles on the (alleged) indi?erence curve.7. If both pepperoni and anchovies are bads, will the indi?erence curve have a positive or a negative slope?3.7. A negative slope. If you give the consumer more anchovies, you’ve made him worse o?, so you have to take away some pepperoni to get him back on his indi?erence curve. In this case the direction of increasing utility is toward the origin.8. Explain why convex preferences means that “averages are preferred to extremes.”3.8. Because the consumer weakly prefers the weighted average of two bundles to either bundle.9. What is your marginal rate of substitution of $1 bills for $5 bills?3.9. If you give up one $5 bill, how many $1 bills do you need to compensate you? Five $1 bills will do nicely. Hence the answer is ?5 or?1/5, depending on which good you put on the horizontal axis.10. If good 1 is a “neutral,” what is its marginal rate of substitution for good 2?3.10. Zero—if you take away some of good 1, the consumer needs zero units of good 2 to compensate him for his loss. ANSWERS A1311. Think of some other goods for which your preferences might be concave.3.11. Anchovies and peanut butter, scotch and Kool Aid, and other similar repulsive combinations.4 Utility1. The text said that raising a number to an odd power was amonotonic transformation. What about raising a number to an even power? Is this a monotonic transformation? (Hint: consider the case f(u)=u^2.)4.1. The function f(u)=u^2 is a monotonic transformation for positive u, but not for negative u.2. Which of the following are monotonic transformations?(1) u =2 v?13;(2) u = ?1/v^2;(3)u =1/v^2; (4)u = ln v; (5)u = ?e^?v; (6)u = v^2; (7) u = v^2 for v>0; (8) u = v^2 for v<0.4.2. (1) Yes. (2) No (works for v positive). (3) No (works for v negative).(4) Yes (only de?ned for v positive). (5) Yes. (6) No. (7) Yes. (8) No.3. We claimed in the text that if preferences were monotonic, then a diagonal line through the origin would intersect each indi?erence curve exactly once. Can you prove this rigorously? (Hint: what would happen if it intersected some indi?erence curve twice?)4.3. Suppose that the diagonal intersected a given indi?erence curve at two points, say (x,x) and (y,y). Then either x>y or y>x, which means that one of the bundles has more of both goods. But if preferences are monotonic, then one of the bundles would have to be preferred to the other.4. What kind of preferences are represented by a utility function of thex1+x2form u(x1,x2)=? What about the utility function v(x1,x2)= 13x1 + 13x2?4.4. Both represent perfect substitutes.5. What kind of preferences are represented by a utility function of thex2x2 form u(x1,x2)=x1 +? Is the utility function v(x1,x2)=x2 1 +2x1+x2 a monotonic transformation of u(x1,x2)?4.5. Quasilinear preferences. Yes.x1x26. Consider the utility function u(x1,x2)=. What kind of pref- erences does it represent? Is the function v(,)= ax1x2x12x22 monotonic transformation of u(,)? Is the function w(,) =x1x2x1x2x12a monotonic transformation of u(,)?x22x1x24.6. The utility function represents Cobb-Douglas preferences. No. Yes.7. Can you explain why taking a monotonic transformation of a utility function doesn’t change the marginal rate of substitution?4.7. Because the MRS is measured along an indi?erence curve, and utility remains constant along an indi?erence curve.5 Choice1. If two goods are perfect substitutes, what is the demand function forgood 2?5.1.=0 when>, = m/when <, and anything betweenx2 p2p1x2p2p2p10 and m/p2 when = .p1p22. Suppose that indi?erence curves are described by straight lines witha slope of ?b. Given arbitrary prices and money income p1, p2, and m, what will the consumer’s optimal choices look like?5.2. The optimal choices will be x1 = m/p1 and x2 = 0 ifp1/p2 b, and any amount on the budget line if p1/p2 = b.3. Suppose that a consumer always consumes 2 spoons of sugar with each cup of co?ee. If the price of sugar is p1 per spoonful and the price of co?ee is p2 per cup and the consumer has m dollars to spend on co?ee and sugar, how much will he or she want to purchase?5.3. Let z be the number of cups of co?ee the consumer buys. Then we know that 2z is the number of teaspoons of sugar he or she buys. We must satisfy the budget constraint2z + z = m.p1p2Solving for z we havez =m2p1+ p2.4. Suppose that you have highly nonconvex preferences for ice cream and olives, like those given in the text, and that you face prices p1, p2 and have m dollars to spend. List the choices for the optimal consumption bundles.5.4. We know that you’ll either consume all ice cream or all olives. Thus the two choices for the optimal consumption bundles will be x1 = m/,p1 x2 = 0, or x1 = 0, x2 = m/.p25. If a consumer has a utility function u(x1,x2)=x1x4 2, what fraction of her income will she spend on good 2?5.5. This is a Cobb-Douglas utility function, so she will spend 4/(1 + 4) = 4/5 of her income on good 2.6. For what kind of preferences will the consumer be just as well-o?facing a quantity tax as an income tax?5.6. For kinked preferences, such as perfect complements, where the change in price doesn’t induce any change in demand.6 Demand1. If the consumer is consuming exactly two goods, and she is always spending all of her money, can both of them be inferior goods?6.1. No. If her income increases, and she spends it all, she must be purchasing more of at least one good.2. Show that perfect substitutes are an example of homotheticpreferences.6.2. The utility function for perfect substitutes is u(,)=+ .x1 x2 x1 x2Thus if u(,) >u (,), we have + >+ . It follows x1 x2 y1 y2 x1 x2 y1y2that t+ t> t+ t, so that u(t,t) >u (t, t).x1 x2 y1y2 x1 x2 y1y23. Show that Cobb-Douglas preferences are homothetic preferences.6.3. The Cobb-Douglas utility function has the property that u(t,t)=x1 x2= 2 = t 2 = t*u(x1,). ( t x1)a( t x2)1?a t a t1?a x1a x21?a x1a x21?a x2Thus if u(,) >u (,), we know that u(t,t) >u (t,), so x1 x2 y1 y2 x1 x2 y1t y2that Cobb-Douglas preferences are indeed homothetic.4. The income o?er curve is to the Engel curve as the price o?er curveis to ...?6.4. The demand curve.5. If the preferences are concave will the consumer ever consume bothof the goods together?6.5. No. Concave preferences can only give rise to optimal consumptionbundles that involve zero consumption of one of the goods.。

《中级微观经济学》试题与答案

《中级微观经济学》试题与答案一、名词解释（5道题）1. 消费者剩余-解释：消费者愿意支付的最高价格与实际支付价格之间的差额，是消费者获得的净收益。

2. 边际替代率-解释：消费者在维持同一效用水平的情况下，愿意用一种商品替代另一种商品的比率。

3. 规模经济-解释：当企业的生产规模扩大时，平均成本随着产量的增加而下降的现象。

4. 纳什均衡-解释：在博弈论中，每个参与者在给定其他参与者策略的情况下，所选择的最佳策略组合。

5. 帕累托最优-解释：资源配置的一种状态，无法在不使任何人变得更差的情况下，使某些人变得更好。

二、填空题（5道题）1. 在短期生产函数中，边际产量递减规律是指（在其他投入固定时，增加一个单位可变投入，产量的增加量递减）。

2. 供给弹性大于1表示（供给是弹性的）。

3. 无差异曲线上的点表示（消费者获得相同效用的不同商品组合）。

4. 在完全竞争市场中，长期均衡时，企业的经济利润是（零）。

5. 价格上限政策可能导致的直接结果是（商品短缺）。

三、单项选择题（5道题）1. 下列哪一项不是完全竞争市场的特征？（）。

- A. 大量的买者和卖者- B. 同质产品- C. 自由进入和退出市场- D. 厂商具有定价权-答案：D2. 在长期，完全竞争市场中的企业会选择生产在（）。

- A. 平均成本最低的产量- B. 边际成本最低的产量- C. 平均总成本等于价格的产量- D. 边际成本等于价格的产量-答案：D3. 如果一种商品的需求是价格无弹性的，那么价格上升10%将导致需求量（）。

- A. 增加10%- B. 减少10%- C. 减少少于10%- D. 减少多于10%-答案：C4. 在垄断市场中，垄断者的利润最大化产量是（）。

- A. 边际成本等于价格- B. 边际收益等于价格- C. 边际收益等于边际成本- D. 平均成本等于边际成本-答案：C5. 在短期内，完全竞争企业的供给曲线是（）。

- A. 平均总成本曲线- B. 平均可变成本曲线- C. 边际成本曲线- D. 边际成本曲线位于平均可变成本曲线之上的部分-答案：D四、多项选择题（5道题）1. 影响需求的主要因素有（）。

中级微观经济学考试题库及答案

中级微观经济学考试题库及答案一、单项选择题1.经济学上所说的稀缺性是指( )。

a.性欲的无限性b.资源的绝对稀缺性c.资源的相对有限性d.欲望的相对有限性2.稀缺性问题( )。

a.只存在于依靠市场机制的经济中b.只存有于靠中央计划机制的经济中c.存在于所有经济中d.只存有于发展中国家中3.稀缺性的存在意味着( )。

a.必须做出挑选b.人们的生活水平会不断下降c.一个人不必须把今天能够买的东西领至明天去卖d.需要用政府计划来配置资源4.稀缺性的存有意味著( )。

a.决策者必须作出选择b.政府必须干涉经济c.不能让自由市场来作重要的决策d.竞争就是不好的，必须歼灭它5.当资源不足以满足所有人的需要时( )。

a.消费者必须具备全然信息b.政府必须决定谁的要求能被满足c.必须有一套市场系统起至促进作用d.必须作出选择6.当资源非常有限而性欲无穷时，人们必须( )。

a.作出选择b.减少他们的希望c.使公共利益优先于个人利益d.自给自足7.选择具有重要性，基本上是因为( )。

a.人们就是欲求的，他们的犯罪行为就是为了个人私欲b.相对于人类社会的无穷欲望而言，所需要的资源总是不足的c.一个经济必须依靠市场去化解稀缺性的问题d.政府对市场的影响有限8.因为资源就是匮乏的，所以( )。

a.必须作出选择b.政府必须分配资源c.某些人必须忍受贫穷d.除了富人之外所有人都必须做出挑选9.由政府来解决生产什么、如何生产和为谁生产这三个经济学基本问题的经济制度属于( )。

a.混合经济b.计划经济c.市场经济d.有计划的商品经济10.做为经济学的一个分支，微观经济学主要研究( )。

a.国际贸易b.不发达国家的经济快速增长c.通货膨胀和失业d.家庭和企业的经济犯罪行为二、判断题1.如果社会不存有资源的稀缺性，也就不能产生经济学。

( )2.只要有人类社会，就会存在稀缺性。

( )3.资源的稀缺性同意了资源可以获得充分利用，不能发生资源浪费现象。

中级微观经济学题库及答案佩洛夫

中级微观经济学题库及答案佩洛夫1. 假设一定时期内消费者的个人收入增加了20% ，由此导致消费者对某商品的需求下降了12% ，这在一定程度上可以说明该商品属于() [单选题] *A 高档品B 边际商品C 低档品(正确答案)D 必需品答案解析：正确答案：C答案解析1、此题考查需求收入弹性概念。

2、需求收入弹性为负值的商品称为“低档品”。

3、易错点：题干中提到的“下降了”为减少，则为负值；如果题干问的是“需求增加了12%”，则需求上升比例小于个人收入增加比例才为正值。

2. 假设其他条件不变，当生产成本上升时，在坐标图上就表现为这种农产品的() [单选题] *A 供给曲线将向左移动(正确答案)B 需求曲线将向左移动C 需求曲线将向右移动D 供给曲线将向右移动答案解析：正确答案：A答案解析供给曲线的形状是由供给规律，即商品或服务的供给量和价格呈同方向变化所决定的。

成本水平上升，供给曲线向左移动3. 甲商品和乙商品的价格按相同比例上升，而收入不变，则预算线的变化是（）[单选题] *A 不变B 发生旋转C 向右上方平行移动D 向左下方平行移动(正确答案)答案解析：正确答案：D答案解析本题考查相对价格变动对预算线的影响。

两种商品的价格同比例同方向变动,并不会改变预算线的斜率,只会导致预算线发生平移。

如果价格同比例上升,表示消费者的全部收入用来购买其中任何一种商品的数量减少,预算线向左下方平行移动。

同理,如果价格同比例下降,预算线向右上方平行移动4. 不论在何种市场上,企业实现利润最大化的决策原则都是()。

[单选题] *A 边际收益等于边际成本(正确答案)B 边际收益大于边际成本C 价格大于平均成本D 劳动的边际产量为零答案解析：正确答案：A答案解析本题考查实现利润最大化的决策原则。

企业实现利润最大化的决策原则是：边际成本=边际收益。

5. 关于需求价格弹性和生产者或者销售者总销售收入关系的说法,正确的是()[单选题] *A在需求弹性系数大于1时,价格下降会使销售收入增加(正确答案)B在需求弹性系数等于1时,价格下降会使销售收入增加C在需求弹性系数等于1时,价格下降会使销售收入减少D在需求弹性系数小于1时,价格下降会使销售收入增加答案解析：正确答案：A答案解析本题考查需求价格弹性和总销售收入的关系。

中级微观经济学考试试题答案完整版

一．简答题1.机会成本相关答：是指为了得到某种东西而所要放弃另一些东西的最大价值。

在稀缺性的世界中选择一种东西意味着放弃其他东西。

一项选择的机会成本，也就是所放弃的物品或劳务的价值。

机会成本是指在资源有限条件下，当把一定资源用于某种产品生产时所放弃的用于其他可能得到的最大收益。

2.劣等品和低档品的逻辑推导（P78）答：低档品或劣等品（inferior goods）：指消费量随收入的上升而下降的物品。

对于正常商品，替代效应与价格呈反方向变动，收入效应也与价格成反方向变动，所以总效应与价格成反方向变动，因此正常商品的需求曲线向右下方倾斜。

对于低档品来说，替代效应与价格成反方向变动，收入效应与价格同向变动，但替代效应大于收入效应的作用，总效应与价格反方向变动，需求曲线向右下方倾斜。

吉芬商品，替代效应与价格反方向变动，收入效应与价格通向变动，收入效应极大地大于替代效应，使总效应与价格同向变动，其需求线向右上方倾斜。

二．计算题1.生产理论：已知企业的生产函数要素价格需求函数企业生产量求：市场长期均衡的产品价格和企业数量EG A: 已知生产函数为Q=KL-0.5L2—0.32K2，其中Q表示产量，K表示资本，L表示劳动，若K=10，求：（1）写出劳动的平均产量函数和边际产量函数。

（2）分别计算出当总产量、平均产量和边际产量达到极大值时，厂商雇佣的劳动量。

（3）证明当APL达到最大值时，APL=MPL=2AN A:（1）TP=Q=10L-0.5L^2-30 把K=10带进去边际产量（MPL ）函数就是上式对L 求导。

MPL=10-L平均产量（APL ）函数就是总产量除以投入的劳动。

APL=TP/L=10-0.5L-30/L（2）当TP 最大时，MPL=0。

令MPL=10-L=0 ，解得L=10，所以当劳动投入量L=10时，劳动的总产量TP 达到极大值。

当APL 最大时，是APL 与MPL 相交的时候。

令APL 的导数=0，解得L=2倍根号15（负值舍去），所以当劳动投入量L=2倍根号15 时，劳动的平均产量达到极大值。

中级微观经济学复习题及答案

中级微观经济学复习题及答案一、简述题1.如果我们看到（Y1，Y2）可以同时获得，但消费者选择（x1，，那么，（x1，x2）？（Y1，Y2）的结论正确吗？（第2章，问题1）x2）答：不正确，因为也可能是消费者恰好在这两个消费束之间无差异。

也就是说，根据题目的已知条件我们只能断定（x1，x2）?（y1，y2），这是弱偏好。

对本题加上什么样的假设前提，题目中的断定就是正确的？如果加上消费者的偏好是严格凸的这一限制条件，断定（x1，x2）?（y1，y2）就是正确的。

因为严格凸性条件下，最优解若存在则只有一个。

22.如果消费者的偏好可以通过效用函数U（x1，x2）确定？10（x12？2x1x2？x2）？50来形容述，那么对消费者而言，商品1和商品2是完全替代的吗？为什么？（第二章，题5）答：这两种商品完全被替代了，也就是说，它们的边际替代率是恒定的。

边际替代率是指在消费者保证同等效用的条件下，用一种商品替代另一种商品的比率。

因此，商品1的边际效用为mu1=Du/dx1=10（2x1+2x2），商品2的边际效用为mu2=Du/DX2=10（2x1+2x2）商品1对商品2的边际替代率mrs12=mu1/mu2=1。

满足完全替代品的效用函数特征，因此这个说法是正确的。

3.假设消费者首先购买X和Y商品，muxpx，若px下降，py保持?muypy不变，再假定x的需求价格弹性大于1，则y的购买量会不会发生变化？（第三章，题3）答：原始消费是平衡的。

假设消费者在X商品上的支出是M1m1?pxx。

对该式求px的导数有，dm1dxdxpx？？二甲苯？十、十、1.因为X的需求，dpxdpx？dpxx？dm1？0，也就是说，随着价格下降，消费者在xdpx上支出的价格弹性大于1（绝对值），因此商品上的支出会增加。

那么，消费者花在y商品上的支出会减少，从而y的购买一量会减少。

4.生产函数是q=f（k，l）=k（第5章，问题2）答：?t?1，f(tk,tl)?(tk)0.25?(tl)0.25?t0.5k0.25l0.25?tk0.25l0.25?tf(k,l)，故规模报酬递减。

中级微观经济学期末考试及答案

中级微观经济学期末考试及答案一、选择题（每题2分，共20分）1、当某消费者对商品W的消费达到饱和点时，则边际效用MUₓ为（ C ）A、正值B、负值C、零D、不确定2、当吉芬商品的价格上升时，应该有（ B ）A、替代效应为正值，收入效应为负值，且前者的作用大于后者B、替代效应为负值，收入效应为正值，且前者的作用小于后者C、替代效应为负值，收入效应为正值，且前者的作用大于后者D、替代效应为正值，收入效应为负值，且前者的作用小于后者3、对于生产函数Q=F（L,K）和成本方程C=WL+RK来说，在最优的生产要素组合点上应该有( ABC )A、等产量曲线和成本线相切B、 MRTSᴋʟ=W/RC、MP ʟ/W=MP ᴋ/RD、MP ʟ=MP ᴋ4、在短期成本曲线图形中，从原点出发的射线与TC曲线相切的点上，必有（ BCD ）A、MC曲线处于下降阶段B、AC最小C、AC=MCD、MC曲线处于上升阶段5、对于完全竞争厂商，如果在厂商的短期产量是，AR小于SAC但大于AVC，则厂商（ B ）A、亏损，立即停产B、亏损，但继续生产C、亏损，生产或不生产都行D、获得正常利润，继续生产6、垄断厂商实现利润最大化的均衡条件是（ C ）A、MR=ACB、AR=ACC、MR=MCD、AR=MC7、在垄断厂商的长期均衡点上，不可能出现的情形是（ B ）A、价格P大于LACB、价格P等于最小的LACC、价格P小于LACD、AR大于MR8、市场失灵的表现是（ ABCD ）A、信息不完全B、存在垄断C、公共物品生产D、外部性9、在非完全竞争的产品市场，企业的边际收益线（ A ）A.向右下方倾斜，在AR的下方B.向右上方倾斜，在AR的下方C.平行于横轴，在AR的上方D.不能确定10、当边际产量大于平均产量时，平均产量（ C ）A.递减 B不变 C.递增 D先增后减二、判断题（每题1分，共10分）1、西方经济学所说的吉芬商品是一种劣等品。

中级微观经济学题库与答案

...一、名词辨析1.规范分析与实证分析；实证分析方法：实证分析不涉及价值判断，只讲经济运行的内在规律，也就是回答“是什么”的问题；实证分析方法的一个基本特征它提出的问题是可以测试真伪的，如果一个命题站得住脚，它必须符合逻辑并能接受经验数据的检验。

规范分析方法：规范分析以价值判断为基础，以某种标准为分析处理经济问题的出发点，回答经济现象“应当是什么”以及“应当如何解决”的问题，其命题无法证明真伪。

2. 无差异曲线与等产量线；无差异曲线是指这样一条曲线，尽管它上面的每一点所代表的商品组合是不同的，但消费者从中得到的满足程度却是相同的。

等产量线表示曲线上每一点的产量都相等，是由生产出同一产量的不同投入品组合所形成的曲线。

3. 希克斯补偿与斯卢茨基补偿;希克斯补偿是指当商品价格发生变化后，要维持原有效用水平所需补偿的货币数量。

斯卢茨基补偿是指当商品价格发生变化后，要维持原有消费水平所需补偿的货币数量。

4. 边际替代率与边际技术替代率；边际替代率是指，消费者在增加额外一单位商品X之后，若要保持满足水平不变而必须放弃的商品 Y的数量。

边际替代率就等于无差异曲线在该点的斜率的绝对值。

边际技术替代率是指，当只有一种投入品可变时，要增加产量，企业必须投入更多的另一种投入品；当两种投入品都可变时，企业往往会考虑用一种投入品来替代另一种投入品。

等产量线斜率的绝对值就是两种投入品的边际技术替代率。

5. 边际产出与边际收益产出边际产出，就是指在其他生产资源的投入量不变的条件下, 由于增加某种生产资源一个单位的投入 , 相应增加的产出量。

当产出以产量表示时 , 即为边际产量 ; 当产出以产值表示时 , 即为边际产值。

边际收益产出是指，额外单位劳动给企业带来的额外收益是劳动的边际产品与产品的边际收益的乘积。

6.显性成本与隐性成本；显性成本：是指厂商在生产要素市场上购买或租用所需要的生产要素的实际支出；隐性成本：是指厂商本身所拥有的且被用于该企业生产过程的那些生产要素的总价格。

中级微观经济学习题及答案

ANSWERS1 The Market1. Suppose that there were 25 people who had a reservation price of $500, and the 26th person had a reservation price of $200. What would the demand curve look like?1.1. It would be constant at $500 for 25 apartments and then drop to $200.2. In the above example, what would the equilibrium price be if there were 24 apartments to rent? What if there were 26 apartments to rent?What if there were 25 apartments to rent?1.2. In the ﬁrst case, $500, and in the second case, $200. In the third case, the equilibrium price would be any price between $200 and $500.3. If people have diﬀerent reservation prices, why does the market demand curve slope down?1.3. Because if we want to rent one more apartment, we have to oﬀer a lower price. The number of people who have reservation prices greater than p must always increase as p decreases.4. In the text we assumed that the condominium purchasers camefrom the inner-ring people—people who were already renting apartments. What would happen to the price of inner-ring apartments if all of the condominium purchasers were outer-ring people—the people who were not currently renting apartments in the inner ring?1.4. The price of apartments in the inner ring would go up since demand for apartments would not change but supply would decrease.5. Suppose now that the condominium purchasers were all inner-ring people, but that each condominium was constructed from two apartments. What would happen to the price of apartments? 1.5. The price of apartments in the inner ring would rise.6. What do you suppose the eﬀect of a tax would be on the number of apartments that would be built in the long run?1.6. A tax would undoubtedly reduce the number of apartments supplied in the long run.7. Suppose the demand curve is D(p) = 100−2p. What price would the monopolist set if he had 60 apartments? How many would he rent? What price would he set if he had 40 apartments? How manywould he rent?1.7. He would set a price of 25 and rent 50 apartments. In the second case he would rent all 40 apartments at the maximum price the market would bear. This would be given by the solution to D(p) = 100−2p = 40, which is p∗ = 30.8. If our model of rent control allowed for unrestricted subletting, who would end up getting apartments in the inner circle? Would the outcome be Pareto eﬃcient?1.8. Everyone who had a reservation price higher than the equilibrium price in the competitive market, so that the ﬁnal outcome would be Pareto eﬃcient. (Of course in the long run there would probably be fewer new apartments built, which would lead to another kind of ineﬃciency.)2 Budget Constraint1. Originally the consumer faces the budget line p1x1 + p2x2 = m. Then the price of good 1 doubles, the price of good 2 becomes 8 times larger, and income becomes 4 times larger. Write down an equation for the new budget line in terms of the original prices and income.2.1. The new budget line is given by 2p1x1 +8p2x2 =4m.2. What happens to the budget line if the price of good 2 increases, but the price of good 1 and income remain constant?2.2. The vertical intercept (axis) decreases and the horizontal intercept (axis) stays the same. Thus the budget line becomes ﬂatter.3. If the price of good 1 doubles and the price of good 2 triples, does the budget line become ﬂatter or steeper?2.3. Flatter. The slope is −2/3.4. What is the deﬁnition of a numeraire good?2.4. A good whose price has been set to 1; all other goods’ prices are measured relative to the numeraire good’s price.5. Suppose that the government puts a tax of 15 cents a gallon on gasoline and then later decides to put a subsidy on gasoline at a rate of 7 cents a gallon. What net tax is this combination equivalent to? 2.5. A tax of 8 cents a gallon.6. Suppose that a budget equation is given by+= m. The government decides to impose a lump-sum tax of u, a quantity tax on good 1 of t, and a quantity subsidy ongood 2 of s. What is the formula for the new budget line?2.6. (+ t)+(−s)= m−u.7. If the income of the consumer increases and one of the prices decreases at the same time, will the consumer necessarily be at least as well-oﬀ?2.7. Yes, since all of the bundles the consumer could aﬀord before are aﬀordable at the new prices and income.3 Preferences1. If we observe a consumer choosing (,)when(,) is available one time, are we justiﬁed in concludingthat (,)>(,)?3.1. No. It might be that the consumer was indiﬀerent between the two bundles. All we are justiﬁed in concluding is that(,)> (,).2. Consider a group of people A, B, C and the relation “at least as tall as,” as in “A is at least as tall as B.” Is this relation transitive? Is it complete?3.2. Yes to both.3. Take the same group of people and consider the relation “strictly taller than.” Is this relation transitive? Is it reﬂexive? Is it complete?3.3. It is transitive, but it is not complete—two people might be the same height. It is not reﬂexive since it is false that a person is strictly taller than himself.4. A college football coach says that given any two linemen A and B, he always prefers the one who is bigger and faster. Is this preference relation transitive? Is it complete?3.4. It is transitive, but not complete. What if A were bigger but slower than B? Which one would he prefer?5. Can an indiﬀerence curve cross itself? For example, could Figure3.2 depict a single indiﬀerence curve?3.5. Yes. An indiﬀerence curve can cross itself, it just can’t cross another distinct indiﬀerence curve.6. Could Figure 3.2 be a single indiﬀerence curve if preferences are monotonic?3.6. No, because there are bundles on the indiﬀerence curve that have strictly more of both goods than other bundles on the (alleged) indiﬀerence curve.7. If both pepperoni and anchovies are bads, will the indiﬀerence curve have a positive or a negative slope?3.7. A negative slope. If you give the consumer more anchovies, you’ve made him worse oﬀ, so you have to take away some pepperoni to get him back on his indiﬀerence curve. In this case the direction of increasing utility is toward the origin.8. Explain why convex preferences means that “averages are preferred to extremes.”3.8. Because the consumer weakly prefers the weighted average of two bundles to either bundle.9. What is your marginal rate of substitution of $1 bills for $5 bills? 3.9. If you give up one $5 bill, how many $1 bills do you need to compensate you? Five $1 bills will do nicely. Hence the answer is −5 or−1/5, depending on which good you put on the horizontal axis.10. If good 1 is a “neutral,” what is its marginal rate of substitution for good 2?3.10. Zero—if you take away some of good 1, the consumer needs zero units of good 2 to compensate him for his loss.ANSWERS A1311. Think of some other goods for which your preferences might be concave.3.11. Anchovies and peanut butter, scotch and Kool Aid, and other similar repulsive combinations.4 Utility1. The text said that raising a number to an odd power was a monotonic transformation. What about raising a number to an even power? Is this a monotonic transformation? (Hint: consider the case f(u)=u^2.)4.1. The function f(u)=u^2 is a monotonic transformation for positive u, but not for negative u.2. Which of the following are monotonic transformations?(1) u =2 v−13; (2) u = −1/v^2; (3)u =1/v^2; (4)u = ln v; (5)u = −e^−v; (6)u = v^2; (7) u = v^2 for v>0; (8) u = v^2 for v<0.4.2. (1) Yes. (2) No (works for v positive). (3) No (works for v negative). (4) Yes (only deﬁned for v positive). (5) Yes. (6) No. (7) Yes. (8) No.3. We claimed in the text that if preferences were monotonic, then a diagonal line through the origin would intersect each indiﬀerence curve exactly once. Can you prove this rigorously? (Hint: what would happen if it intersected some indiﬀerence curve twice?)4.3. Suppose that the diagonal intersected a given indiﬀerence curve at two points, say (x,x) and (y,y). Then either x>y or y>x, which means that one of the bundles has more of both goods. But if preferences are monotonic, then one of the bundles would have to be preferred to the other.4. What kind of preferences are represented by a utility function of the form u(x1,x2)=? What about the utility function v(x1,x2)= 13x1 + 13x2?4.4. Both represent perfect substitutes.5. What kind of preferences are represented by a utility function of the form u(x1,x2)=x1 +? Is the utility function v(x1,x2)=x2 1 +2x1+x2 a monotonic transformation of u(x1,x2)?4.5. Quasilinear preferences. Yes.6. Consider the utility function u(x1,x2)=. What kind of pref- erences does it represent? Is the function v(,)=a monotonic transformation of u(,)? Is the function w(,)= a monotonic transformation ofu(,)?4.6. The utility function represents Cobb-Douglas preferences. No. Yes.7. Can you explain why taking a monotonic transformation of a utility function doesn’t change the marginal rate of substitution? 4.7. Because the MRS is measured along an indiﬀerence curve, and utility remains constant along an indiﬀerence curve.5 Choice1. If two goods are perfect substitutes, what is the demand function for good 2?5.1.=0 when>, = m/when<, and anything between 0 and m/p2 when = .2. Suppose that indiﬀerence curves are described by straight lines with a slope of −b. Given arbitrary prices and money income p1, p2, and m, what will the consumer’s optimal choices look like?5.2. The optimal choices will be x1 = m/p1 and x2 = 0 ifp1/p2 <b ,x1 = 0 andx2 = m/p2 if p1/p2 >b, and any amount on the budget line if p1/p2 = b.3. Suppose that a consumer always consumes 2 spoons of sugar with each cup of coﬀee. If the price of sugar is p1 per spoonful and the price of coﬀee is p2 per cup and the consumer has m dollars to spend on coﬀee and sugar, how much will he or she want to purchase?5.3. Let z be the number of cups of coﬀee the consumer buys. Then we know that 2z is the number of teaspoons of sugar he or she buys. We must satisfy the budget constraint2z + z = m.Solving for z we havez =.4. Suppose that you have highly nonconvex preferences for ice cream and olives, like those given in the text, and that you face prices p1, p2 and have m dollars to spend. List the choices for the optimal consumption bundles.5.4. We know that you’ll either consume all ice cream or all olives. Thus the two choices for the optimal consumption bundles will be x1 = m/, x2 = 0, or x1 = 0, x2 = m/.5. If a consumer has a utility function u(x1,x2)=x1x4 2, what fraction of her income will she spend on good 2?5.5. This is a Cobb-Douglas utility function, so she will spend 4/(1 + 4) = 4/5 of her income on good 2.6. For what kind of preferences will the consumer be just as well-oﬀfacing a quantity tax as an income tax?5.6. For kinked preferences, such as perfect complements, where the change in price doesn’t induce any change in demand.6 Demand1. If the consumer is consuming exactly two goods, and she is always spending all of her money, can both of them be inferior goods?6.1. No. If her income increases, and she spends it all, she must be purchasing more of at least one good.2. Show that perfect substitutes are an example of homothetic preferences.6.2. The utility function for perfect substitutes is u(,)=+ . Thus ifu(,) >u (,), we have + >+ . It follows that t+ t> t+ t, so that u(t,t) >u (t, t).3. Show that Cobb-Douglas preferences are homothetic preferences.6.3. The Cobb-Douglas utility function has the property that u(t,t)==2 = t 2 = t*u(x1,).Thus if u(,) >u (,), we know that u(t,t) >u (t,), so that Cobb-Douglas preferences are indeed homothetic.4. The income oﬀer curve is to the Engel curve as the price oﬀer curve is to ...?6.4. The demand curve.5. If the preferences are concave will the consumer ever consume both of the goods together?6.5. No. Concave preferences can only give rise to optimal consumption bundles that involve zero consumption of one of the goods.6. Are hamburgers and buns complements or substitutes?6.6. Normally they would be complements, at least for non-vegetarians.7. What is the form of the inverse demand function for good 1 in the case of perfect complements?6.7. We know that x1 = m/(p1 + p2). Solving for p1 as a function of the other variables, we have p1 = m x1 −p2.8. True or false? If the demand function is x1 = −p1, then the inverse demand function is x = −1/p1.6.8. False.7 Revealed Preference1. When prices are (p1,p2) = (1 ,2) a consumer demands (x1,x2) =(1 ,2), and when prices are ( q1,q2) = (2 ,1) the consumer demands (y1,y2) = (2 ,1). Is this behavior consistent with the model of maximizing behavior?7.1. No. This consumer violates the Weak Axiom of Revealed Preference since when he bought (x1,x2) he could have bought (y1,y2) and vice versa. In symbols:p1x1 + p2x2 =1×1+2×2=5> 4=1×2+2×1=p1y1 + p2y2andq1y1 + q2y2 =2×2+1×1=5> 4=2×1+1×2=q1x1 + q2x2.2. When prices are (p1,p2) = (2 ,1) a consumer demands (x1,x2) = (1 ,2), and when prices are ( q1,q2) = (1 ,2) the consumer demands (y1,y2) = (2 ,1). Is this behavior consistent with the model of maximizing behavior?7.2. Yes. No violations of WARP are present, since the y-bundle is not aﬀordable when the x-bundle was purchased and vice versa.3. In the preceding exercise, which bundle is preferred by the consumer, the x-bundle or the y-bundle?7.3. Since the y-bundle was more expensive than the x-bundle when the x-bundle was purchased and vice versa, there is no way to tell which bundle is preferred.4. We saw that the Social Security adjustment for changing prices would typically make recipients at least as well-oﬀas they were at the base year. What kind of price changes would leave them just as well-oﬀ, no matter what kind of preferences they had?7.4. If both prices changed by the same amount. Then the base-year bundle would still be optimal.5. In the same framework as the above question, what kind of preferences would leave the consumer just as well-oﬀas he was in the base year, for all price changes?7.5. Perfect complements.8 Slutsky Equation1. Suppose a consumer has preferences between two goods that are perfect substitutes. Can you change prices in such a way that the entire demand response is due to the income eﬀect?8.1. Yes. To see this, use our favorite example of red pencils and blue pencils. Suppose red pencils cost 10 cents a piece, and blue pencils cost 5 cents a piece, and the consumer spends $1 on pencils. She would then consume 20 blue pencils. If the price of blue pencils falls to 4 cents a piece, she would consume 25 blue pencils, a change which is entirely due to the income eﬀect.2. Suppose that preferences are concave. Is it still the case that the substitution eﬀect is negative?8.2. Yes.3. In the case of the gasoline tax, what would happen if the rebate to the consumers were based on their original consumption of gasoline, x, rather than on their ﬁnal consumption of gasoline, x’?8.3. Then the income eﬀect would cancel out. All that would be left would be the pure substitution eﬀect, which would automatically be negative.4. In the case described in the preceding question, would the government be paying out more or less than it received in tax revenues?8.4. They are receiving tx’ in revenues and paying out tx, so they are losing money.5. In this case would the consumers be better oﬀ or worse oﬀ if the tax with rebate based on original consumption were in eﬀect?8.5. Since their old consumption is aﬀordable, the consumers would have to be at least as well-oﬀ. This happens because the governmentis giving them back more money than they are losing due to the higher price of gasoline.9 Buying and Selling1. If a consumer’s net demands are (5,−3) and her endowment is (4,4), what are her gross demands?9.1. Her gross demands are (9,1).2. The prices are (p1,p2) = (2 ,3), and the consumer is currently consuming (x1,x2) = (4 ,4). There is a perfect market for the two goods in which they can be bought and sold costlessly. Will the consumer necessarily prefer consuming the bundle (y1,y2) = (3 ,5)? Will she necessarily prefer having the bundle (y1,y2)?9.2. The bundle (y1,y2) = (3 ,5) costs more than the bundle (4,4) at the current prices. The consumer will not necessarily prefer consuming this bundle, but would certainly prefer to own it, since she could sell it and purchase a bundle that she would prefer.3. The prices are (p1,p2) = (2 ,3), and the consumer is currently consuming (x1,x2) = (4 ,4). Now the prices change to (q1,q2) = (2 ,4). Could the consumer be better oﬀ under these new prices?9.3. Sure. It depends on whether she was a net buyer or a net seller of the good that became more expensive.4. The U.S. currently imports about half of the petroleum that it uses. The rest of its needs are met by domestic production. Could the price of oil rise so much that the U.S. would be made better oﬀ?9.4. Yes, but only if the U.S. switched to being a net exporter of oil.5. Suppose that by some miracle the number of hours in the day increased from 24 to 30 hours (with luck this would happen shortly before exam week). How would this aﬀect the budget constraint?9.5. The new budget line would shift outward and remain parallel to the old one, since the increase in the number of hours in the day is a pure endowment eﬀect.6. If leisure is an inferior good, what can you say about the slope of the labor supply curve?9.6. The slope will be positive.10 Intertemporal Choice1. How much is $1 million to be delivered 20 years in the future worth today if the interest rate is 20 percent?10.1. According to Table 10.1, $1 20 years from now is worth 3 cents today at a 20 percent interest rate. Thus $1 million is worth .03×1,000,000 = $30,000 today.2. As the interest rate rises, does the intertemporal budget constraint be- come steeper or ﬂatter?10.2. The slope of the intertemporal budget constraint is equal to −(1+r). Thus as r increases the slope becomes more negative (steeper).3. Would the assumption that goods are perfect substitutes be valid in a study of intertemporal food purchases?10.3. If goods are perfect substitutes, then consumers will only purchase the cheaper good. In the case of intertemporal food purchases, this implies that consumers only buy food in one period, which may not be very realistic.4. A consumer, who is initially a lender, remains a lender even aftera decline in interest rates. Is this consumer better oﬀor worse oﬀafter the change in interest rates? If the consumer becomes a borrower after the change is he better oﬀ or worse oﬀ?10.4. In order to remain a lender after the change in interest rates, the consumer must be choosing a point that he could have chosen under the old interest rates, but decided not to. Thus the consumer must be worse oﬀ. If the consumer becomes a borrower after thechange, then he is choosing a previously unavailable point that cannot be compared to the initial point (since the initial point is no longer available under the new budget constraint), and therefore the change in the consumer’s welfare is unknown.5. What is the present value of $100 one year from now if the interest rate is 10%? What is the present value if the interest rate is 5%?10.5. At an interest rate of 10%, the present value of $100 is $90.91. At a rate of 5% the present value is $95.24.11 Asset Markets1. Suppose asset A can be sold for $11 next period. If assets similar toA are paying a rate of return of 10%, what must be asset A’s current price?11.1. Asset A must be selling for 11/(1 + 0.10) = $10.2. A house, which you could rent for $10,000 a year and sell for $110,000 a year from now, can be purchased for $100,000. What is the rate of return on this house?11.2. The rate of return is equal to (10,000 + 10,000)/100,000 = 20%.3. The payments of certain types of bonds (e.g., municipal bonds) are not taxable. If similar taxable bonds are paying 10% and everyone faces a marginal tax rate of 40%, what rate of return must the nontaxable bonds pay?11.3. We know that the rate of return on the nontaxable bonds, r, must be such that (1−t)= r, therefore (1−0.40)*0.10 =0 .06 = r.4. Suppose that a scarce resource, facing a constant demand, will be exhausted in 10 years. If an alternative resource will be available at a price of $40 and if the interest rate is 10%, what must the price of the scarce resource be today?11.4. The price today must be 40/(1 +0 .10)^10 = $15.42.12 Uncertainty1. How can one reach the consumption points to the left of the endowment in Figure 12.1?12.1. We need a way to reduce consumption in the bad state and increase consumption in the good state. To do this you would have to sell insurance against the loss rather than buy it.2. Which of the following utility functions have the expected utility property? (a) u(c1,c2,π1,π2)=a(π1c1 + π2c2), (b) u(c1,c2,π1,π2)=π1c1 + π2c2 2, (c)u(c1,c2,π1,π2)=π1 lnc1 + π2 lnc2 + 17.12.2. Functions (a) and (c) have the expected utility property (they are aﬃne transformations of the functions discussed in the chapter), while (b) does not.3. A risk-averse individual is oﬀered a choice between a gamble that pays $1000 with a probability of 25% and $100 with a probability of 75%, or a payment of $325. Which would he choose?12.3. Since he is risk-averse, he prefers the expected value of the gamble, $325, to the gamble itself, and therefore he would take the payment.4. What if the payment was $320?12.4. If the payment is $320 the decision will depend on the form of the utility function; we can’t say anything in general.5. Draw a utility function that exhibits risk-loving behavior for small gambles and risk-averse behavior for larger gambles.12.5. Your picture should show a function that is initially convex, but then becomes concave.6. Why might a neighborhood group have a harder time self insuring for ﬂood damage versus ﬁre damage?12.6. In order to self-insure, the risks must be independent. However, this does not hold in the case of ﬂood damage. If one house in the neighborhood is damaged by a ﬂood it is likely that all of the houses will be damaged.13 Risky Assets1. If the risk-free rate of return is 6%, and if a risky asset is available with a return of 9% and a standard deviation of 3%, what is the maximum rate of return you can achieve if you are willing to accept a standard deviation of 2%? What percentage of your wealth would have to be invested in the risky asset?13.1. To achieve a standard deviation of 2% you will need to invest x = σx/σm =2 /3 of your wealth in the risky asset. This will result in a rate of return equal to (2/3)0.09 + (1−2/3)0.06 = 8%.2. What is the price of risk in the above exercise?13.2. The price of risk is equal to (rm − rf)/σm = (9− 6)/3 = 1. That is, for every additional percent of standard deviation you can gain 1% of return.3. If a stock has a β of 1.5, the return on the market is 10%, and the risk- free rate of return is 5%, what expected rate of return should this stock oﬀer according to the Capital Asset Pricing Model? If theexpected value of the stock is $100, what price should the stock be selling for today?13.3. According to the CAPM pricing equation, the stock should oﬀer an expected rate of return of rf + β(rm −rf)=0.05 + 1.5(0.10−0.05) =0 .125 or 12.5%. The stock should be selling for its expected present value, which is equal to 100/1.125 = $88.89.14 Consumer’s Surplus1. A good can be produced in a competitive industry at a cost of $10 per unit. There are 100 consumers are each willing to pay $12 each to consume a single unit of the good (additional units have no value to them.) What is the equilibrium price and quantity sold? The government imposes a tax of $1 on the good. What is the deadweight loss of this tax?14.1. The equilibrium price is $10 and the quantity sold is 100 units. If the tax is imposed, the price rises to $11, but 100 units of the good will still be sold, so there is no deadweight loss.2. Suppose that the demand curve is given by D(p) = 10−p. What is the gross beneﬁt from consuming 6 units of the good?14.2. We want to compute the area under the demand curve to the left of the quantity 6. Break this up into the area of a triangle with a base of 6 and a height of 6 and a rectangle with base 6 and height 4.Applying the formulas from high school geometry, the triangle has area 18 and the rectangle has area 24. Thus gross beneﬁt is 42.3. In the above example, if the price changes from 4 to 6, what is the change in consumer’s surplus?14.3. When the price is 4, the consumer’s surplus is given by the area of a triangle with a base of 6 and a height of 6; i.e., the consumer’s surplus is 18. When the price is 6, the triangle has a base of 4 and a height of 4, giving an area of 8. Thus the price change has reduced consumer’s surplus by $10.4. Suppose that a consumer is consuming 10 units of a discrete good and the price increases from $5 per unit to $6. However, after the price change the consumer continues to consume 10 units of the discrete good. What is the loss in the consumer’s surplus from this price change?14.4. Ten dollars. Since the demand for the discrete good hasn’t changed, all that has happened is that the consumer has had to reduce his expenditure on other goods by ten dollars.15 Market Demand1. If the market demand curve is D(p) = 100 − .5p, what is the inverse demand curve?15.1. The inverse demand curve is P(q) = 200−2q.2. An addict’s demand function for a drug may be very inelastic, but the market demand function might be quite elastic. How can this be?15.2. The decision about whether to consume the drug at all could well be price sensitive, so the adjustment of market demand on the extensive margin would contribute to the elasticity of the market demand.3. If D(p) = 12−2p, what price will maximize revenue?15.3. Revenue is R(p) = 12 p−2p2, which is maximized at p = 3.4. Suppose that the demand curve for a good is given by D(p) = 100/p. What price will maximize revenue?15.4. Revenue is pD(p) = 100, regardless of the price, so all prices maximize revenue.5. True or false? In a two good model if one good is an inferior good the other good must be a luxury good.15.5. True. The weighted average of the income elasticities must be 1, so if one good has a negative income elasticity, the other good musthave an elasticity greater than 1 to get the average to be 1.16 Equilibrium1. What is the eﬀect of a subsidy in a market with a horizontal supply curve? With a vertical supply curve?16.1. The entire subsidy gets passed along to the consumers if the supply curve is ﬂat, but the subsidy is totally received by the producers when the supply curve is vertical.2. Suppose that the demand curve is vertical while the supply curve slopes upward. If a tax is imposed in this market who ends up paying it?16.2. The consumer.3. Suppose that all consumers view red pencils and blue pencils as perfect substitutes. Suppose that the supply curve for red pencils is upward sloping. Let the price of red pencils and blue pencils be and . What would happen if the government put a tax only on red pencils?16.3. In this case the demand curve for red pencils is horizontal at the price , since that is the most that they would be willing to pay for a red pencil. Thus, if a tax is imposed on red pencils, consumers will end up paying for them, so the entire amount of the tax will end。

中级微观经济学题库及答案佩洛夫

2、需求收入弹性为负值的商品称为“低档品”。

3、易错点：题干中提到的“下降了”为减少，则为负值；如果题干问的是“需求增加了12%”，则需求上升比例小于个人收入增加比例才为正值。

两种商品的价格同比例同方向变动,并不会改变预算线的斜率,只会导致预算线发生平移。

如果价格同比例上升,表示消费者的全部收入用来购买其中任何一种商品的数量减少,预算线向左下方平行移动。

同理,如果价格同比例下降,预算线向右上方平行移动4. 不论在何种市场上,企业实现利润最大化的决策原则都是()。

企业实现利润最大化的决策原则是：边际成本=边际收益。

中级微观期末试题及答案

中级微观期末试题及答案一、选择题1. 以下哪个是市场经济的基本特征？A. 政府对经济活动的直接干预B. 生产要素由政府统一配置C. 市场决定资源配置D. 基尼系数高答案：C2. 市场需求曲线的下降趋势是由于以下哪个原因引起的？A. 商品的价格上涨B. 生产成本的降低C. 人民币升值D. 人口增长答案：A3. 当供给曲线向右移动时，以下哪种情况可能发生？A. 供给量减少B. 需求量增加C. 价格上涨D. 价格下跌答案：C4. 现金是一种什么资源？A. 实物资源B. 金融资源C. 无形资源D. 人力资源答案：C5. 以下哪个是正常货币的特征？A. 可兑换性B. 货币多样性C. 商业银行发行D. 担保性答案：A二、判断题1. 价格与数量的需求关系可以用需求函数来表示。

答案：正确2. 垄断市场存在很高的进入壁垒。

答案：正确3. 价格弹性表示价格变动对需求变动的敏感程度。

答案：错误4. 消费者剩余是指消费者愿意支付的价格与实际支付价格之间的差额。

答案：正确5. 稀缺性是资源配置的决定性特征。

答案：正确三、简答题1. 请简要说明市场供给与个体供给的区别。

市场供给是指在某一时间段内，市场上所有卖者愿意以不同价格出售的某一商品的数量，它是市场上各个卖者个体供给之和。

而个体供给是指某一卖者在不同价格下愿意出售的特定商品数量。

2. 解释需求曲线右移与需求曲线左移的原因。

需求曲线右移是指在价格不变的情况下，需求量增加。

原因可能包括收入增加、人口增加、相关商品价格上涨或个体偏好改变等。

需求曲线左移则表示需求量减少，原因可能包括收入减少、人口减少、相关商品价格下跌或个体偏好变化等。

3. 解释弹性需求与非弹性需求。

弹性需求是指需求量对价格变动的敏感程度高，即当价格上涨时，需求量下降幅度较大；当价格下跌时，需求量增加幅度较大。

非弹性需求则相反，需求量对价格变动的敏感程度较低，即价格上涨时，需求量下降幅度较小；价格下跌时，需求量增加幅度较小。

中级微观经济学复习试题和答案与解析

一、简述题1.如果我们看到在（1y ，2y ）可以同时得到的情况下，消费者却选择了（1x ，2x ），那么，（1x ，2x）（1y ，2y ）的结论是否正确？(第二章，题1) 答：不正确，因为也可能是消费者恰好在这两个消费束之间无差异。

也就是说，根据题目的已知条件我们只能断定（1x ，2x ）（1y ，2y ），这是弱偏好。

对本题加上什么样的假设前提，题目中的断定就是正确的？如果加上消费者的偏好是严格凸的这一限制条件，断定（1x ，2x）（1y ，2y ）就是正确的。

因为严格凸性条件下，最优解若存在则只有一个。

2.若某个消费者的偏好可以由效用函数22121122(,)10(2)50u x x x x x x =++-来描述，那么对消费者而言，商品1和商品2是完全替代的吗？为什么？（第二章，题5）答：两种商品完全替代即它们的边际替代率为常数。

边际替代率是在消费者保证效用相等的条件下，用一种商品替代另一种商品的比率。

因此有：商品1的边际效用为MU 1=du /dx 1=10(2x 1 +2 x 2)商品2的边际效用为MU 2= du /dx 2=10(2x 1 +2 x 2)商品1对商品2的边际替代率MRS 12= MU 1 / MU 2 =1。

满足完全替代品的效用函数特征，因此这个说法是正确的。

3.假定消费者购买x 和y 两种商品，起初，x x y yMU P MU P =，若x P 下降，y P 保持不变，再假定x 的需求价格弹性大于1，则y 的购买量会不会发生变化？（第三章，题3）答：原来消费处于均衡状态。

设消费者花在x 商品上的支出为1m ，则1x m p x =。

对该式求x p 的导数有，11x x x x x p dm dx dx p x x dp dp dp x ⎡⎤=+=+⎢⎥⎣⎦，因x 的需求价格弹性大于1（绝对值），所以有10x dm dp <，即随着价格下降，消费者花在x 商品上的支出会增加。

中级微观经济学习题及部分答案

一、单项选择题（每题0.5分，共15分，将正确答案填入答题纸上）1。

有下列因素除哪一种外都会使需求曲线移动？（B ）a 消费者收入变化；b 商品价格变化；c消费者偏好变化；d 其他相关商品价格变化。

2. 假定某耐用消费品的需求函数Qd=400—5P时的均衡价格为50,当需求函数变为Qd=600—5P时,（供给不变）均衡价格将（B)a 低于50b 高于50c 等于50d 不变3.下列命题中哪个是规范经济学的命题？( A )a。

征税对中等收入家庭是不公平的 c. 1982年8月政府把贴现率降到10%b。

1981年失业率超过9％d。

社会保险税的课税依据现已超过30000美元4。

当供求力量自由作用时，一次谷物歉收通过什么显示在市场上？（B )a.政府规定的购买量限制b。

谷物价格上涨c.劝说人们减少购买量的广告d.谷物贸易量的增加5.某月内，X商品的替代品的价格上升和互补品的价格上升，分别引起X商品的需求变动量为50单位和80单位,则在它们共同作用下该月X商品需求数量:（B ）。

a.增加30单位b.减少30单位c.增加130单位d.减少130单位6。

在完全竞争市场中，（ C ）。

a。

消费者是价格接受者，而企业不是 b.消费者和企业都不是价格接受者c.消费者和企业都是价格接受者d.企业是价格接受者，而消费者不是7。

LAC曲线（A）.a.当LMC＜LAC时下降，而当LMC＞LAC时上升b.随LMC曲线下降而下降c．随LMC曲线上升而上升 d.通过LMC曲线的最低点8．一个企业在以下哪种情况下应该关闭?（ A )a.P＜A VC b。

P＜SAC c.发生亏损时d。

SMC＞MR9.寡头垄断和垄断竞争之间的主要区别是（C )。

a.厂商的广告开支不同b.非价格竞争的种类不同c。

厂商之间相互影响的程度不同 d.以上都不对10.短期内，完全竞争厂商只能通过对（ D ）调整来实现最大利润。

a.生产规模b。

价格c.全部生产要素d。