上财中微习题2

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中微第二次作业题参考答案

由一阶条件可解得该商品的需求曲线为（2）
，其反需求曲线为
0.05
O
25
（c）新的市场价格 p’=p*(1+10%)=0.055，它对应的
0.055 0.05
O
20.66 25
如上图，可计算出新的消费者剩余所以，消费者剩余的变化量后，消费者剩余下降了 1.14。，即在其他条件不变的情况下，市场价格上升
I3 I2 I1 U1 0 I U2 X1 U3
0 （c）第一种情况 x2 U3 U2 U1
x1
0
P.C.C. x1
O
第二种情况、
，在第二种情况中，随着 p1 的下降，会经历
、
这一过程，消费者的选择也会由 x2 变到 x1。如图：
x2 U2
U1 0 P.C.C. x1
O
当
时， x1 的需求量为 0；当且
（3）由需求函数及所给的收入和价格水平可以计算出消费者原来的消费为（14，,78）（78 为消费者买牛奶后持有的货币），如果消费者维持这一消费水平，则现在只需要 14×2+78=106 元，即降价使他省出（120-106）=14 元，现在他用 106 元就相当于原来的 120 元钱。
2 2 2
2. 已知一个消费者对牛奶的需求函数为：
x 10
I 10 p
这里，x 为一周内牛奶的消费量，I=120 元为收入，p=3 元(每桶)，现在假定牛奶价格从 3 元降为 2 元。问： (1)该价格变化对该消费者的需求总效应是多少? (2)请用 Hicks 分析法计出价格变化的替代效应和收入效应。 (3)如该消费者维持原消费水平，降价会使他省出多少钱 ?现在他用多少钱就相当于原来的 120 元钱。

上财投资学教程第二课后练习第章习题集

习题集一、判断题（40题）1、贝塔值为零的股票的预期收益率为零。

F2、CAPM模型表明，如果要投资者持有高风险的证券，相应地也要更高的回报率。

T3、通过将0.75的投资预算投入到国库券，其余投向市场资产组合，可以构建贝塔值为0.75的资产组合。

F4、CAPM模型认为资产组合收益可以由系统风险得到最好的解释。

T5、如果所有的证券都被公平定价，那么所有的股票将提供相等的期望收益率。

F6、投资组合中成分证券相关系数越大，投资组合的相关度高，投资组合的风险就越小。

F7、对于不同的投资者而言，其投资组合的效率边界也是不同的。

F8、偏好无差异曲线位置高低的不同能够反映不同投资者在风险偏好个性上的差异。

T9、在市场模型中，β大于1的证券被称为防御型证券。

F10、同一投资者的偏好无差异曲线不可能相交。

T11、收益的不确定性即为投资的风险，风险的大小与投资时间的长短成反比。

F12、对于某一股票，股利收益率越高，持有期回收率也就越高。

F13、资产组合的收益率是组合中各资产收益率的代数相加后的和。

F14、证券投资的风险主要体现在未来收益的不确定性上，即实际收益与投资者预期收益的背离。

T15、市场风险指的是市场利率变动引起证券投资收益不确定的可能性。

F16、利率风险对于各种证券都是有影响的，但是影响程度会因证券的不同而有区别，对于固定收益证券的要大于对浮动利率证券的影响。

T17、购买力风险属于系统风险，是由于货币贬值给投资者带来实际收益水平下降的风险。

T18、非系统风险可以通过组合投资的方式进行分散，如果组合方式恰当，甚至可以实现组合资产没有非系统风险。

T19、信用风险属于非系统风险，当证券发生信用风险时，投资股票比投资债券的损失大。

F20、经营风险是由于公司经营状况变化而引起盈利水平的改变，从而产生投资者预期收益下降的可能。

经营风险在任何公司中都是存在的，所以投资者是无法规避经营风险的。

F21、收益与风险的关系表现在一般情况下，风险较大的证券，收益率也较高；收益率较低的证券，其风险也较小。

上海财经大学中级微观经济学试卷一

诚实考试吾心不虚，公平竞争方显实力，考试失败尚有机会，考试舞弊前功尽弃。

上海财经大学《中级微观经济学》课程考试卷（A）闭卷课程代码101560 课程序号0996 / 10652013 ——2014 学年第2 学期请仔细阅读以下内容，并签名承诺。

一旦您签名，将作为诚信承诺的依据，若您在考试过程中出现舞弊行为，将按照学校有关规定严肃处理；若您拒绝进行诚信承诺，将取消考试资格。

考试结束后，考卷必须与答题纸同时上交。

未上交考卷，或没有诚信签字的考卷将计以零分。

诚信承诺书我谨以至诚承诺，在此次考试过程中，我绝无任何舞弊行为，也绝不帮助他人舞弊。

学生签名：年月日I.单选题（每题2分）1. 在完全垄断市场中，如果市场A中的价格高于市场B中的价格，我们可以推断：a. 市场A 中需求价格弹性大于市场B 中的需求价格弹性。

b. 市场A 中需求价格弹性小于市场B 中的需求价格弹性。

c. 市场A和市场B 有着相同的需求价格弹性。

d. 以上都不对。

2. A 商品有着正的外部性，意味着：a. 生产该商品的边际社会成本高于边际私人成本。

b. 生产该商品的边际社会成本低于边际私人成本。

c. 边际社会收益等于生产者呃边际收益。

d. 边际社会收益小于生产者呃边际收益。

3. 如果一个商品的供给数量小于社会最优数量，我们可以推断在市场上该商品有：a. 正外部性。

b. 不安全信息。

c. 负外部性。

……………………………………………………………装订线…………………………………………………d. 逆向选择。

4. 私人商品和公共商品的主要区别在于： a. 前者有个体提供，后者由政府提供。

b. 前者由个体消费，后者由政府消费。

c. 前者是竞争性的排他性的，后者则不是。

d. 前者不是竞争性的，也不是排他性的，后者是的。

5. 一个垄断者可以在两个市场中要求不同的价格。

她提供商品在第一个市场中的需求曲线是q= 500 – 2p ，在第二个市场中的需求曲线是q = 1500 – 6p 。

中微第二次作业题参考答案

5. 一个具有冯.诺依曼效用函数的人拥有 160000 单位的初始财产，但他面临火灾风险：一种发生概率为 5%的火灾会使其损失 70000；另一种发生概率为 5%的火灾会使其损失 120000。他的效用函数形式是 U (W ) W 。若他买保险，保险公司要求他自己承担前 7620 单位的损失(若火灾发生)。什么是这个投保人愿支付的最高保险金? 解：设该投保人愿意支付的最高保险金为 R。如果他购买保险，不发生火灾时，他的财产为（160000-R），发生火灾时，无论为那种火灾，他的财产都为（160000-R-7620），因此，若他购买保险，则其期望效用为：；如果此人不购买保险，那么他的期望效用为：
I3
I2
I1
P.C.C.
0
I p3
I p2
I p1
电影
（4）消费者对其消费的两种商品的效用函数为 u( x1 , x2 ) ax1 bx2 （a）请绘出该消费者对这两种商品的无差异曲线。（b）当消费者收入增加时，如果 x1 商品的价格小于 x2 商品的价格，请画出该消费者对商品 x1 的收入—消费曲线（I.C.C）和恩格尔曲线。（c）当消费者的收入 I 给定时，如果 x1 商品的价格小于 x2 商品的价格，请画出该消费者对商
由 R=11004。
可解得此人愿意支付的最高保险金额
6. Ms.Fogg is planning an around-the-world trip on which she plans to spend $10000. The utility from the trip is a function of how much she actually spends on it(Y), given by

上财中微习题2

上财中微习题2Intermediate MicroeconomicsFall 2009 – Dr. LiProblem Set 2Due on Oct. 28th in className IDTRUE-FALSE (2’*8=16’)1. Bernice’s utility function is U(x, y) = min{x, y}. The price of x used to be 3 but rose to 4. The price of y remained at 1. Her income is 12. She would need an income of $15 to be able to afford a bundle as good as her old one at the new prices.a. Trueb. False2. If there is a price increase for a good that Marilyn consumes, her compensating variation is the change in her income that allows her to purchase her new optimal bundle at the original prices.a. Trueb. False3. If the equation for the demand curve is q = 20 - 2p, then the ratio of marginal revenue to price is constant as price changes.a. Trueb. False4. If the amount of money that people are willing to spend on a good stays the same when its price doubles, then demand for that good must have a price elasticity of demand smaller in absolute value than 1.a. Trueb. False5. If the production function is f (x, y) = min{2x + y, x + 2y}, then there are constant returns to scale.a. Trueb. False6. firm produces one output with one input and has decreasing returns to scale. The price that it pays per unit of input and the price it gets per unit of output are independent of the amount that this firm buys or sells. If the government taxes its net profits at some percentage rate and subsidizes its inputs at the same percentage rat e, the firm’s profit-maximizing output will not change.a. Trueb. False7. If there are increasing returns to scale, then costs per unit of output decrease as you move downward and to the right along an iso-cost line.a. Trueb. False8. A firm uses a single variable input x to produce outputs according to the production function f(x) = 300x - 6x2. This firm has fixed costs of $400. This firm’s short-run marginal cost curve lies below its short-run average variable cost curve for all positive values of x.a. Trueb. FalseMULTIPLE CHOICE (4’*16=64’)1. Reginald is fond of cigars. His utility function is U(x, c) = x + 10c －.5c^2, where c is the number of cigars he smokes per week and x is the money that he spends on the consumption ofother goods. Reginald has $200 a week to spend. Cigars used to cost him $1 each, but their price went up to $2 each. This price increase was as bad for him as losing income ofa. $5.b. $7.25.c. $9.d. $8.e. $8.50.2. Sam’s utility function is U(x, y) = 2x + y, where x is the number of x’s he consumes per week and y is the number of y’s he consumes per week. Sam has $200 a week to spend. The price of x is $4. Sam currently doesn’t consume any y. Sam has received an invitation to join a club devoted to the consumption of y. If he joins the club, Sam can get a discount on the purchase of y. If he belonged to the club, he could buy y for $1 a unit. How much is the most Sam would be willing to pay to join this club?a. Nothingb. $100 a weekc. $50 a weekd. $40 a weeke. None of the above.3. Sir Plus has a demand function for mead that is given by the equation D(p) = 100 - p. If the price of mead is $60, how much is Sir Plus’s net consumer’s surplus?a. $40b. $800c. $1,600d. $400e. $3,9004. If Bernice (whose utility function is min{x, y}, where x is herconsumption of earrings and y is money left for other stuff) had an income of $12 and was paying a price of $4 fora pair of earrings, then if the price of earrings went up to $6, the equivalent variation of the price change would bea. $4.80.b. $3.43.c. $1.71.d. $9.60.e. $4.11.5. Given his current income, Rico’s demand for bagels is related to the price of bagels by the equation Q = 540 - 16P. Rico’s income elasticity of demand for bagels i s known to be equal to 0.5 at all prices and incomes. If Rico’s income quadruples, his demand for bagels will be related to the price of bagels by the equationa. Q = 540 - 16P.b. Q = 2,160 - 64P.c. Q = 540 - 32P.d. Q = 1,080 - 32Pe. Q = 1,080- 16P.6. At a large institution of higher learning, the demand for football tickets at each game is 100,000 - 8,000p. If the capacity of the stadium at that university is 60,000 seats, what is the revenue maximizing price for this university to charge per ticket?a. $6.25b. $5c. $12.50d. $3.13e. $18.757. A firm has the production function f(x, y) = 60x4/5y1/5.The slope of the firm’s isoquant at the point (x, y) = (40, 80) is (pick the closest one)a. -0.50.b. -4.c. -0.25.d. -8.e. -0.25.8. A firm has the production function f(x1, x2) = x0.601x0.302. The isoquant on which output is 803/10 has the equationa. x2 = 80x-21.b. x2 = 80x3.331.c. x1/x2 = 2.d. x2 = 80x-0.301.e. x1 = 0.30x-0.702.9. A firm has a production function f(x, y) = 1.80(x0.80 + y0.80)2 whenever x > 0 and y > 0. When the amounts of both inputs are positive, this firm hasa. decreasing returns to scale.b. constant returns to scale.c. increasing returns to scale if x + y > 1 and decreasing returns to scaleotherwise.d. increasing returns to scale.e. increasing returns to scale if output is less than 1 and decreasing returns toscale if output is greater than 1.10. A competitive firm produces output using three fixed factors and one variable factor. The firm’s short-run production function is q = 524x - 4x2, where x is the amount of variable factorused. The price of the output is $3 per unit and the price of the variable factor is $12 per unit. In the short run, how many units of x should the firm use?a. 130b. 32c. 25d. 65e. None of the above.11. A profit-maximizing competitive firm uses just one input, x. Its production function is q = 4x1/2. The price of output is $12 and the factor price is $3. The amount of the factor that the firm demands isa. 64.b. 16.c. 60.d. 8.e. None of the above.12. A competitive firm’s production function is f(x1, x2) = 12x1/21 + 4x1/22. The price of factor 1 is $1 and the price of factor 2 is $2. The price of output is $4. What is the profit-maximizing quantity of output?a. 304b. 608c. 300d. 612e. 29213. If the short-run marginal costs of producing a good are $20 for the first 400 units and $30 for each additional unit beyond 400, then in the short run, if the market price of output is $21, a profit-maximizing firm willa. produce a level of output where marginal revenue equals marginal costs.b. not produce at all, since marginal costs are increasing.c. produce up to the point where average costs equal $21.d. produce as much output as possible since there are constant returns to scale.e. produce exactly 400 units.14. A firm’s production function is q = 12x0.50y0.50, where x and y are the amounts of factors x and y that the firm uses as inputs. If the firm is minimizing unit costs and if the price of factor x is 5 times the price of factor y, the ratio in which the firm will use factors x and y is closest toa. x/y = 0.20.b. x/y = 0.40.c. x/y = 1.d. x/y = 1.67.e. x/y = 5.15. A competitive firm has the three-factor production function f(x, y, z) = (x +y)1/2z1/2. The factor prices used to be w x = $1, w y = $2, and w z = $3. Suppose that the price of factor y doubled while the other two prices stayed the same. Then the cost of productiona. increased by more than 10% but less than 50%.b. increased by 50%.c. doubled.d. stayed the same.e. increased by more than 50% but did not double.16. A new metal alloy is discovered that uses copper and zinc in fixed proportions where each unit of the alloy requires 4 units of zinc and 2 units of copper. If no other inputs are required, if the price of zinc is $2 per unit, and the price of copper is $5 per unit and if total output is 4,000 units, what is the average cost per unit of output?a. $.50b. $2c. $18d. $20e. $25PROBLEMS (20’)1. Suppose that the inverse demand function for wool is p = A/q for some constant A. Suppose that 1/4 of the world’s wool is produced in Australia.a. If Australian wool production increases by 1% and the rest of the world holds its output constant, what will be the effect on the world price of wool? (2’)b. How does the marginal revenue to Australia from an extra unit of wool relate to the price of wool? (3’)2. On separate axes, draw typical production isoquants for each of the following production functions.a. f(x, y) = min{2x, x + y}. (2’)b. f(x, y) = xy. (3’)c. f(x, y) = x + min{x, y}. (3’)d. f(x, y) = x + y1/2. (3’)3. If the production function for tuna casseroles is min{x1, x22}, where x1 is the amount of factor 1 and x2 is the amount of factor x2, find the cost function for tuna casseroles. (4’)。

上海财经大学中级宏观经济学期末考试题

4. (10 points) Consider the market-clearing model without capital, and use it to discuss the following question about an agricultural economy. Suppose, because of weather conditions, there is a temporary drought expected to last for a year or two. What are your predictions for the changes in output, consumption, work eﬀort, the real interest rate, and real wages in the short-run? What will happen to the price level? Illustrate your answer with diagrams.
2. (5 points) If the real interest rate increases what happens to desired saving at the household level? If we observe an increase in the real interest, what will happen to aggregate saving? Would your answers be diﬀerent for the models with and without capital?
1
3. (5 points) Between the end of World War II and the mid 1980s, the velocity of money in the United States was rising. What might explain this observation?

资料：上财中微习题3

Intermediate MicroeconomicsFall 2009 – Dr. LiProblem Set 3Due on Nov. 25th in className IDTRUE-FALSE (3’*6=18’)1. In a perfectly competitive industry, the demand curve for the total output of the industry may be downward sloping.2. If some firm in an industry has the production function F(x, y) = x3/4y3/4, where x and y are the only two inputs in producing the good, then that industry cannot be competitive in the long run.3. A monopolist will always equate marginal revenue and marginal cost when maximizing profit.4. Third-degree price discrimination occurs when a monopolist sells output to different people at different prices but every unit that an individual buys costs the same amount.5. It is possible that a profit-maximizing monopolist who is able to practice first-degree (perfect) price discrimination would sell a quantity x such that the demand curve for his product is inelastic when the quantity sold is x.6. In Cournot equilibrium each firm chooses the quantity that maximizes its own profits assuming that the firm’s rival will continue to sell at the same price as before.MULTIPLE CHOICE (15’*4=60’)1. A profit-maximizing firm continues to operate even though it is losing money. It sells its product at a price of $100.a. Average total cost is less than $100.b. Average fixed cost is less than $100.c. Marginal cost is increasing.d. Average variable cost is less than $100.e. Marginal cost is decreasing.2. A competitive firm uses two variable factors to produce its output, with a production function q = min{x1, x2}. The price of factor 1 is $4 and the price of factor 2 is $5. Due to a lack of warehouse space, the company cannot use more than 17 units of x1. The firm must pay a fixed cost of $136 if it produces any positive amount but doesn’t have to pay this cost if it produces no output. What is the smallest integer price that would make a firm willing to produce a positive amount?a. $36b. $33c. $21d. $9e. $173. Suppose that Dent Carr’s long-run total cost of repairing s cars per week is c(s) = 3s2 + 12. If the price he receives for repairing a car is $24, then in the long run, how many cars will he fix per week if he maximizes profits?a. 6b. 4c. 0d. 8e. 124. Chirimollas grow only on the island of Socorro, off the coast of Mexico. They need very little soil, so virtually an unlimited supply can be grown at a cost of $4 per unit. When they are exported to the United States, half of the chirimollas that are shipped rot on the boat and are dumped in the ocean. Shipping costs are $1 for every unit that is put on board a ship. The demand function for chirimollas in the United States is given by the equation q = 10,000 - 20p2. If chirimollas are competitively supplied, the number of units that are sold in the United States will bea. 8,000.b. 9,500.c. 9,680.d. 9,190.e. 9,000.5. A firm uses a single input to produce its output, which is sold in a competitive market. It gets quantity discounts on purchases of its input. If it buys x units of the input, the price it must pay per unit of input is 25/x+ 4. If it buys no inputs, it doesn’t have to pay anything. The firm’s production function is f(x) = 60x - x2. If the price of th e firm’s output is 1, the profit-maximizing amount of input to buy isa. 56.b. 0.c. 42.d. 28.e. None of the above.6. A monopolist faces the inverse demand curve p = 64 - 2q. At what level of output is his total revenue maximized?a. 24b. 26c. 8d. 32e. 167. The demand for a monopolist’s output is 6,000/(p + 2)2, where p is the price it charges. At a price of $3, the elasticity of demand for the monopolist’s output isa. -1.b. -2.20.c. -1.20.d. -1.70.e. -0.70.8. The demand for a monopolist’s output is 6,000/(p + 7)2, where p is its price. It has constant marginal costs equal to $5 per unit. What price will it charge to maximize its profits?a. $33b. $12c. $26d. $17e. $59. A monopolist sells in two markets. The demand curve for her product is given by p1 = 122 - 2x1 in the first market and p2 = 306 - 5x2 in the second market, where x i is the quantity sold in market i and p i is the price charged in market i. She has a constant marginal cost of production, c = 6, and no fixed costs. She can charge different prices in the two markets. What is the profit-maximizing combination of quantities for this monopolist?a. x1 = 58 and x2 = 32.b. x1 = 29 and x2 = 30.c. x1 = 59 and x2 = 29.d. x1 = 39 and x2 = 28.e. x1 = 49 and x2 = 40.10. A price-discriminating monopolist sells in two separate markets such that goods sold in one market are never resold in the other. It charges p1 = $5 in one market and p2 = $10 in the other market. At these prices, the price elasticity in the first market is -1.40 and the price elasticity in the second market is -0.10. Which of the following actions is sure to raise the monopolists profits?a. Lower p2.b. Raise p2.c. Raise p1 and lower p2.d. Raise both p1 and p2.e. Raise p2 and lower p1.11. Roach Motors has a monopoly on used cars in Enigma, Ohio. By installing secret microphones in the showroom, the friendly salespersons at Roach are able to learn each customer’s willingness to pay and can therefore practice first-degree price discrimination, extracting from each customer his entire consumer’s surplus. The inverse demand function for cars in Enigma is P = 2,000 - 10Q. Roach Motors purchases its stock of used cars at an auction in Cleveland for $500 each. Roach motors willa. sell 75 cars for a total profit of $56,250.b. sell 150 cars at a price of $300 a car.c. sell 150 cars for a total profit of $112,500.d. sell 180 cars and make a total profit of $180,000.e. shut down since revenue will not cover variable costs.12. An industry has two firms each of which produces output at a constant unit cost of $10 per unit. The demand function for the industry is q = 1,000,000/p. The Cournot equilibrium price for this industry isa. $5.b. $10.c. $15.d. $20.e. $25.13. A city has two major league baseball teams, A and B. The number of tickets sold by either team depends on the price of the team’s own tickets and the price of the other team’s tickets. If team A charges P a for its tickets and team B charges P b for its tickets, then ticket sales, measured in hundreds of thousands per season, are 10 - 2P a + P b for team A and 20 + P a - 2P b for team B. The marginal cost of an extra spectator is zero for both teams. Each team believes the other’s price is independent of its own choice of price, and each team sets its own price so as to maximize its revenue. What price do they charge per ticket?a. Team A charges 4 and team B charges 6.b. Team A charges 6 and team B charges 5.c. Team A charges 5 and team B charges 8.d. Team A charges 4 and team B charges 12.e. None of the above.14. The inverse demand function for fuzzy dice is p = 20 - q. There are constant returns to scale in this industry with unit costs of $8. Which of the following sets of statements is completely true?a. Monopoly output is 6. Cournot duopoly total output is 8. A Stackelberg leader’s output is 8.b. Monopoly output is 8. Cournot duopoly total output is 8. A Stackelberg leader’s output is 8.c. Monopoly output is 6. Cournot duopoly total output is 6. A Stackelberg follower’s output is 3.d. Monopoly output is 6. Cournot duopoly total output is 8. A Stackelberg follower’s output is 3.e. Monopoly output is 6. Cournot duopoly total output is 8. A Stackelberg follower’s output is 4.15. The duopolists Carl and Simon face a demand function for pumpkins of Q =8,200 - 400P, where Q is the total number of pumpkins that reach the market and P is the price of pumpkins. Suppose further that each farmer has a constant marginal cost of $.50 for each pumpkin produced. If Carl believes that Simon is going to produce Q s pumpkins this year, then the reaction function tells us how many pumpkins Carl should produce in order to maximize his profits. Carl’s reaction function isa. R C(Q s) = 4,000 - Q s/2.b. R C(Q s) = 8,200 - 400Q s.c. R C(Q s) = 8,200 - 800Q s.d. R C(Q s) = 2,000 - Q s/2.e. R C(Q s) = 6,000 - Q s.PROBLEMS (22’)1. The price elasticity of demand for gasoline in the United States is equal to 0.15. How should the price elasticity of demand for the individual firm compare to 0.15 (higher, lower, same, can’t tell)? Explain why.(8’)2. A baseball team’s attendance depends on the number of games it wins per season and on the price of its tickets. The demand function it faces is Q = N(20 - p), where Q is the number of tickets (in hundred thousands) sold per year, p is the price per ticket, and N is the fraction of its games that the team wins. The team can increase the number of games it wins by hiring better players. If the team spends C million dollars on players, it will win .7 - 1/C of its games. Over the relevant range, the marginal cost of selling an extra ticket is zero.a. Write an expression for the firm’s profits as a function of ticket price and expenditure on players. (4’)b. Find the ticket price that maximizes revenue. (5’)c. Find the profit-maximizing expenditure on players and the profit-maximizing fraction of games to win. (5’)。

中微第二次测验试卷B答案

中级微观经济学第二次考试（B卷）一．解：（1）征税前：D(p)=S(P); 60-4P=4P, P=7.5,Q=30消费者净剩余CS1=0.5*7.5*30=112.5生产者净剩余PS1=0.5*7.5*30=112.5(2) 征税后：0.5P(D)=P(S) ; P(D)=15-0.25Q; P(S)=0.25Q所以其＝20，P(D)=10,P(S)=5消费者净剩余CS2=0.5*20*5=50生产者净剩余PS2=0.5*20*5=50政府税收收入5×20＝100所以，社会福利改变了：50＋50＋100-112.5-112.5= -25 即减少了25。

二．解：由于2X 和Y完全互补，X与MIN(2X,Y)完全替代，令Z=MIN(2X,Y) 欲求P(Z), 则1=2X=Y, 则P(Z)=0.5P(X)+P(Y)效用函数：U(X,Z)=X+Z(1)P(X)=2,P(Y)=4时，P(Z)=5, 预算方程：2X+4Y=M=200因为，1/2>1/5所以全消费X,则Y=0,Z=OX1=M/2=100 所以，U1=100(2)P(X)=4,P(Y)=4时，P(Z)=6, 预算方程：4X+4Y=M=200仍全部消费X,则Y=0,Z=O，X1=M/4=200/4=50 所以，U2=50(3) CV: 预算方程：4X+4Y=M+CVX3=(M+CV)/4=50+CV/4 U3=X3=U1=100 所以，CV=200(4)EV: 预算方程：2X+4Y=M-EVX4=(M-EV)/2=100-EV/2 U4=X4=U2=50 所以，EV=100三．（1）前50人，MU1/MU2=100-100X=P(X)/P(Y) P(Y)=1Xi=1-P(X)/100 X1=50Xi=50-P(X) (P(X)<=100)同理，后50人，X2=100-P(X)/2 (P(X)<=200)综上，市场需求Q= 150-P(X) (P(X)<=100)100-P(X)/2 (P(X)<=200)0 (P(X)>200)(2) 当Q=S时候，P(X)<=100，150－P(X)=2P(X)-160 ,P(X)=103.3>100(舍)P(X)<=200，100－P(X)/2=2P(X)-160,P(X)=104所以，市场均衡价格104，均衡数量48四．书上P317－318有图及详细解释。

上海财经大学习题整理精华版

习题整理<一>（12.4）1.如果一个偏好是凸的，则消费者只有一个偏好点。

（）2.效用函数u(x,y) = 10+y2+x代表凸状偏好。

（）3.需求曲线向右下方倾向为商品的边际效用决定的，对吗？请用基数效用理论做出解释。

基数效用理论者以边际效用递减规律和建立在该规律上的消费者效用最大化的均衡条件为基础推导消费者的需求曲线。

消费者愿意为商品支付的价格取决于商品的边际效用，商品的边际效用大则商品的需求价格就高，相反就越低。

由于边际效用递减规律的作用，随着商品的消费量的增加，该商品的边际效用递减，则消费者愿意为购买这种商品所愿意支付的价格就随着递减。

4.（上财2003）证明：如果预算线给定，一条无差异曲线U(Qx,Qy)与其相切，试证明切点的坐标为最优商品组合，切点为消费均衡点。

5.例：为刺激消费，政府拟在以下两个方案中选择一个：对购买的某种商品每一单位补贴S （比例补贴）；或者给予消费者收入补贴R（定额补贴）。

假设这两种补贴的总金额相同，请用图分析这两张不同的补贴方式对消费者的选择和效用有什么影响？说明政府应该采用哪一种方案更能提高消费者的效用水平。

6.唐只消费两种水果。

苹果（Qa）和香蕉（Qb）。

他的效用函数为U(Qa,Qb)=QaQb,苹果和香蕉的边际效用分别为MUa和MUb，而且MUa=Qb,MUb=Qa。

唐的收入（I）是120元。

苹果和香蕉的价格Pa=Pb=1.a)求唐的预算线；b)求唐的收入曲线；c)要使唐的效用最大，应分别消费多少Qa,Qb?d)假定唐的收入固定在120元，Pb固定在1元，求唐消费苹果的需求曲线。

e)假定对每单位香蕉收1元的税，要使效用最大，唐需要做何改变？f)假定用总量税来代替每单位的税，要使效用最大，唐应作何改变？g)上两问中的措施是政府获得了同样多的收入，但对唐来说，他更喜欢哪种，为什么？7.如果消费者花掉所有的钱，则不可能所有的商品都是低档品。

（）P498.某消费者按固定比例消费X1和X2，他消费A单位的X1和B单位的X2.为了解这个消费者对于商品X1和X2的需求函数（）（A）让MU1/MU2=p1/p2;（B）解：Ax1=Bx2,p1x1+p2x2=m;（C）解：Ax2=Bx1,p1x1+p2x2=m;（D）根据预算线的方程解就可以了；9.（上财2007）假设一个消费者的效用函数为U(X,Y)=V(X)+Y,下列说法错误的是（）（A）该消费者的偏好具备位似的特征；（B）商品X的收入效应为0；（C）边际替代率与Y无关；（D）商品X的价格变化所引起的消费者效用的变化可用消费者剩余量来精确计算。

上海财经大学中级微观经济学试卷一培训讲学

诚实考试吾心不虚，公平竞争方显实力，考试失败尚有机会，考试舞弊前功尽弃。

上海财经大学《中级微观经济学》课程考试卷（A ）闭卷课程代码 101560 课程序号 0996 / 10652013 ——2014 学年第 2 学期请仔细阅读以下内容，并签名承诺。

一旦您签名，将作为诚信承诺的依据，若您在考试过程中出现舞弊行为，将按照学校有关规定严肃处理；若您拒绝进行诚信承诺，将取消考试资格。

考试结束后，考卷必须与答题纸同时上交。

未上交考卷，或没有诚信签字的考卷将计以零分。

诚信承诺书我谨以至诚承诺，在此次考试过程中，我绝无任何舞弊行为，也绝不帮助他人舞弊。

学生签名：年月日I.单选题（每题2分） 1. 在完全垄断市场中，如果市场A 中的价格高于市场B 中的价格，我们可以推断：a. 市场A 中需求价格弹性大于市场B 中的需求价格弹性。

b. 市场A 中需求价格弹性小于市场B 中的需求价格弹性。

c.市场A 和市场B 有着相同的需求价格弹性。

d. 以上都不对。

2. A 商品有着正的外部性，意味着： a. 生产该商品的边际社会成本高于边际私人成本。

b. 生产该商品的边际社会成本低于边际私人成本。

c. 边际社会收益等于生产者呃边际收益。

d. 边际社会收益小于生产者呃边际收益。

3. 如果一个商品的供给数量小于社会最优数量，我们可以推断在市场上该商品有： a. 正外部性。

b. 不安全信息。

c. 负外部性。

d. 逆向选择。

4. 私人商品和公共商品的主要区别在于： a. 前者有个体提供，后者由政府提供。

b.前者由个体消费，后者由政府消费。

c.前者是竞争性的排他性的，后者则不是。

……………………………………………………………装订线…………………………………………………d. 前者不是竞争性的，也不是排他性的，后者是的。

5. 一个垄断者可以在两个市场中要求不同的价格。

她提供商品在第一个市场中的需求曲线是q= 500 – 2p ，在第二个市场中的需求曲线是q = 1500 – 6p 。

上海财经大学803经济学考研微观部分习题(市场理论习题测试区).doc

市场理论习题测试区一、包含章节：行业供给、完全竞争市场、完全垄断市场、垄断竞争、寡头垄断市场、要素市场、拍卖理论二、模拟习题区判断题1.（判断题）由于在完全竞争市场中每一个厂商都几乎可以看作是相同的，因此可以用单个厂商的市场供给曲线来代表整个完全竞争市场的行业供给曲线。

（）2.（判断题）在完全竞争市场中，政府征税会给社会带来福利损失，而政府补贴会给社会带来福利增加，所以政府要想扩大社会福利，就应该多进行补贴。

（）3.（判断题）完全竞争厂商的长期供给曲线就是其边际成本曲线。

（）4.（判断题）完全竞争厂商的长期供给曲线比短期供给曲线更富有弹性。

（）5.（判断题）垄断厂商的均衡点处，价格需求弹性一定小于1。

（）6.（判断题）如果垄断产品是富有弹性的，一般来说，向垄断厂商征产品销售税会引起一个高于税率的价格的上涨。

（）7.（判断题）垄断竞争厂商有两条需求曲线，即主观需求曲线和客观需求曲线。

（）8.（判断题）在垄断竞争市场中，垄断竞争厂商所面临的需求曲线越平坦，剩余生产能力就会越大，市场经济效率就会越低。

（）9.（判断题）垄断竞争厂商之间只进行价格竞争。

（）10.（判断题）在价格领导模型中，价格追随者面临的是一条剩余需求曲线。

（）11.（判断题）在价格领导者模型中，领导者厂商决定价格，以便在长期里把其它所有厂商挤出该行业。

（）12.（判断题）在古诺模型中，厂商选择价格而让市场去决定产量。

（）13.（判断题）假定有n家相同的厂商处于古诺均衡情况下，试证明此时市场需求曲线的弹性一定大于1/n。

（）14.（判断题）理论上，在寡头垄断市场上，所有厂商均可以获得超额利润。

（）15.（判断题）现实生活中总是出现各种卡特尔串谋现象，这是因为卡特尔的稳定性可以得到保证。

（）16.（判断题）垄断厂商比竞争厂商获得的利润更多，这就意味着垄断厂商在边际上所使用的要素的微小增加比竞争厂商使用的要素的微小增加价值要大（）17.（判断题）假设买方垄断厂商面临的是线性要素供给曲线w（x）=a+bx,那么买方垄断厂商使用1额外单位要素的边际成本会超过要素价格，所以要素价格低于厂商面临竞争性要素市场时的水平。

中微作业答案

上海交通大学安泰经济与管理学院中级微观经济学作业（1）注：（1）请将作业上传至economics_sjtu@（电子版），或直接投入安泰楼2楼的教师信箱中（纸制版），上述两种提交方式可任选一种；（2）最后提交时间：2012年10月12日试回答以下问题：(1)画出需求曲线。

若公寓的短期供给量为5单位，保证公寓市场均衡的价格应为多少？需求曲线如下图所示：若公寓的短期供给量为5单位时，市场均衡价格为18元。

(2)假定政府设定的公寓最高租金为9元，市场是否均衡？若允许转租，则可能出现何种转租现象？转租索要的最高价格可达多少？当政府设定的公寓最高租金为9元时，最高租金低于市场均衡价格，市场并不均衡。

若允许转租，可能会出现以9元租金获得住房的A可能把该住房以9元到18元之间价格转租给没有得到该住房但保留价格为18元的B。

转租所要的最高价格可达18元。

(3)比较政府价格管制与市场竞争的结果。

在市场竞争条件下，一旦住房被租出，就再也没有交易收益可得，因而是帕累托有效的。

而在政府价格管制条件下，因为在市场调节后仍然还有一些交易可以进行，因而一般不会产生帕累托有效率配置。

2.J公司计划用5000元为其新产品做广告，新产品的目标顾客群是MBA学生和MPA学生。

J公司考虑在普通的商业杂志和流行的消费指南上刊登新产品广告。

根据市场调研资料，获知以下信息：(a)商业杂志的广告需要500元，而消费指南的广告只需250元；(b)商业杂志的读者是1000个MBA学生和300个MPA学生；(c)消费指南的读者是300个MBA学生和250个MPA学生；(d)没有人阅读一个以上的广告，阅读了一种杂志的人不会再阅读另一种杂志。

试回答以下问题：(1)若只在商业杂志或消费指南上刊登广告，新产品广告的辐射范围多大？若只在商业杂志上刊登广告，新广告的辐射范围=（5000/500）*1000=10000个MBA学生和（5000/500）*300=3000个MPA学生；同理，若只在消费指南上刊登广告，新广告的辐射范围为6000个MBA学生和5000个MPA学生。

上财研究生高微题库——二、偏好与效用

上财研究⽣⾼微题库——⼆、偏好与效⽤第⼆部分偏好与效⽤第⼀节偏好与选择1. [简单][来⾃Rubinstein P .10]对于定义在集合X 上的偏好关系，定义()I x 为满⾜z X ∈且z x ～的所有z 的集合。

证明：对于任意属于X 的x y 和，都有()()I x I y =或者()()I x I y φ∩=。

证明：根据定义，(){|,}I x z z x z X =∈～，(){|,}I y z z y z X =∈～。

如果x y ～，由～的传递性知，(){|,}{|,}()I x z z x z X z z y z X I y =∈=∈=～～。

如果x y ～不成⽴，我们⽤反证法证明()()I x I y φ∩=。

假设()()I x I y φ∩≠，则存在()w I x ∈，且()w I y ∈。

由()()I x I y 和的定义知，w x ～且w y ～。

由～的传递性知，x y ～，⽭盾。

2. [简单][改编⾃Rubinstein P .50] 证明：在⼀个两种商品的世界⾥，假定偏好满⾜严格单调、传递且凸，并且对于,x ε?都有121211212(,)(,)(2,)x x x x x x εδεδδ?+?++～～，则21δδ≥。

证明：121211212(,)(,)(2,)x x x x x x εδεδδ?+?++～～? 1212(2,)x x εδδ?++<12121(,)(,)x x x x εδ?+～? 1212120.5(2,)0.5(,)x x x x εδδ?+++<121(,)x x εδ?+? 1212(,0.50.5)x x εδδ?++<121(,)x x εδ?+?21δδ≥3. [中等][来⾃⽥国强教授《微观经济理论讲义》] 证明：如果偏好满⾜严格单调，则满⾜单调；如果偏好满⾜单调，则满⾜局部⾮餍⾜；如果满⾜局部⾮餍⾜，则满⾜⾮餍⾜。

证明：由严格单调的定义：x y ≥且x y ≠，则x y ，和单调的定义：x y >>，则x y ，易知偏好满⾜严格单调意味着满⾜单调。

ccer中微习题1至15章-09春赵耀辉老师

Homework Feb. 20, 2009 (Chapters 2 and 3)1.有两种商品x1和x2，价格分别为p1和p2，一个消费者的收入为m 。

当11x x ≥时，政府加从量税t,画出预算集并写出预算线.2. 消费者消费两种商品（x1，x2），如果花同样多的钱可以买（4，6）或（12, 2），写出预算线的表达式。

3．描述中国粮价改革.（1）假设没有任何市场干预，中国的粮价为每斤0.4元，每人收入为100元。

把粮食消费量计为x ，在其它商品上的开支为y ，写出预算线，并画图。

（2）假设每人得到30斤粮票，可以凭票以0.2元的价格买粮食，再写预算约束，画图。

（3）假设取消粮票，补贴每人6元钱，写预算约束并画图。

4．证明两条无差异曲线不能相交。

5．画出一元纸币（x1）和五元纸币（x2）的无差异曲线，计算边际替代率。

6．两种商品中，假定商品1为中性商品，即消费多少不会使消费者更高兴或者更不高兴，商品2为消费者喜欢的商品（good ），画出无差异曲线，计算边际替代率。

Homework 2, Feb. 24, 2009 (Chapters 4 and 5)1．写出下列情形的效用函数，画出无差异曲线，并在给定价格（p 1，p 2）和收入（m ）的情形下求最优消费选择（1）x 1=一元纸币，x 2=五元纸币。

（2）x 1=一杯咖啡，x 2=一勺糖, 消费者喜欢在每杯咖啡加两勺糖。

2．给定下列效用函数，在价格（p 1，p 2）和收入（m ）的情形下求解消费者的最优选择（1） 21212(,)u x x x x =⋅（2）2u x =Homework 3 (February 28, 2009)对下列效用函数推导对商品1的需求函数，反需求函数，恩格尔曲线；在图上大致画出价格提供曲线，收入提供曲线；说明商品一是否正常品、劣质品、一般商品、吉芬商品，商品二与商品一是替代还是互补关系。

1．212x x u +=2．()212,min x x u =3．ba x x u 21⋅=4. 12ln u x x =+,Homework 4, March 3, 20091．当偏好为完全替代时，计算当价格变化时的收入效用和替代效用（注意分情况讨论）。

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