Microeconomics课程试卷B.doc

Microeconomics课程试卷B一、选择题：（共15小题，每小题2分，共30分）1. A Giffen good: A. has an upward-sloping demand curve.B. has a downward-sloping demand curve.C. has a horizontal demand curve.D. has a vertical demand curve.2. The consumer optimum occurs at: A. any point of intersection between the budget line and anindifference curve.B. a point of tangency between the budget line and an indifferencecurve.C. the point where the slope of the indifference curve equalsthe ratio of the quantities.D. a point where the budget line cuts the curve from below.3. The slope of the budget constraint line is equal to:A. the ratio of marginal utilities.B. the ratio of money income to the price of the good on thehorizontal axis.C. the ratio of money income to the price of the good on thevertical axis.D. the relative price of the two goodsthe price of one goodcompared with the price of the other.4.Assume the demand curve for compact discs slopes downwards,and the supply curve slopes upwards. If the price of CD playersdecreases, then:A. the equilibrium price of compact discs will fallB. the equilibrium price of compact discs will riseC. the equilibrium price of compact discs will stay the sameD. None of the above are correct5. Implicit costs are:A. the payments made to labour only.B. the payments made by the firm to others.C. the opportunity cost of resources owned by the firm.D. the same as accounting profit.6. When marginal cost is rising:A. average variable cost may be rising or falling.B. average variable cost must be falling.Caverage variable cost must be rising.D. average fixed cost must be rising.7. Economic profits for perfectly competitive firms: A. will continue in the long run for a few efficient firms.B. will shift the industry demand function rightward.C. will attract new firms into the industry in the long run.D. will result in an increase in long-run equilibrium price.8.If the demand for milk increases when the price of pickles increases(ceteris paribus), then milk and pickles are (A) normal goods. (B) inferior goods.(C) complements in consumption. (D) substitutes in consumption.9. Suppose that all the firms in a competitive industry haveaccess to the same technology and that input prices are not affectedby the size of the industry. If the minimum value of the long-runaverage cost curve is 5, then entry of new firms will occur untilthe market price: A. equals 6B. equals 7C. equals 5 or lessD. exceeds 510 If the demand for a good is relatively inelastic, then (A) the quantity demanded is extremely responsive or sensitive to changesin price.(B) a 10% increase in price causes the quantity demanded to fall by morethan 10%.(C) a 5% decrease in price causes the quantity demanded to rise by lessthan 5%.(D) the substitution and income effects move in the opposite direction.11.If the quantity demanded of bananas increases by 10% when its pricedecreases by 25%, then the price elasticity of banana demand, Ed, is (A) 0.15. (B) 0.4. (C) 0.35. (D) 1.25.12.A consumer who spends all her income on goods X and Y maximizesutility when the (A)total utility of good X equals the total utility of good Y (TUX = TUY).(B) expenditures on good X equal the expenditures on good Y (PX X = PYY).(C) marginal utility of good X equals the marginal utility of good Y (MUX= MUY).(D)marginal utility of the last $1 spent on good X equals the marginalutility of the last $1 spent on good Y (MUX/PX = MUY/PY).13 .If the supply of coffee decreases and the demand for coffee remainsconstant, then the equilibrium price of coffee will _ and the equilibriumquantity of coffee will _. (A) increase, increase. (B) increase, decrease.(C) decrease, increase. (D) decrease, decrease.14.If coffee and tea are substitutes in consumption, then an increase in theprice of tea (A) decreases both the quantity demanded and the supply of coffee.(B) increases the quantity demanded of coffee.(C) decreases the demand for coffee.(D) increases the demand for coffee.15. An oligopolistic market (A) has a small number of rival firms, and each is large relative to themarket.(B) makes the demand for each firm independent of the actions of its rivals.(C) has low entry barriers facing firms that could otherwise enter themarket.(D) is all of the above.二、判断题：（共15小题，每小题1分，共15分）1. According to the Law of Demand, a decrease in the price of sodaincreases the demand demanded for soda. 2. If beer is an inferior good for a consumer named Fred, then (ceterisparibus) a decrease in Freds income decreases his demand for beer. 3. If coffee and tea are substitutes in consumption, then an increase in theprice of tea decreases both the quantity demanded and the supply of coffee. 4. If cheese demand is relatively inelastic, then an increase in the supply ofcheese will a. increase the income (total revenue) of cheese producers. 5 In the long run all costs can vary.6 If average fixed cost is $50 at an output of 20 units, it would decline to$25 if output were increased to 40 units.7. A perfectly competitive firm j faces a downward-sloping, relativelyelastic demand curve.8. A perfectly competitive firms SR supply curve is given by the firmsAVC curve for market prices above the minimum of the MC curve. 9. A perfectly competitive industry is in LR equilibrium when every firmproduces at its profit maximizing output level.10. Monopolists can control the price.三、名词解释（共5小题，每小题3分，共15分）1. Price Elasticity of Demand: Measures the percentage change in quantitydemanded for a one percent change in price, ceteris paribus.2 Marginal Cost: MC is the change in total cost due to the production ofone more unit of output.3. Opportunity cost: the value of the most highly valued forgone alternative4.Consumer surplus:The difference between what a consumer is willing topay and what she has to pay.5. A Nash equilibrium is a situation in which economic actors interactingwith one another each choose their best strategy given the strategies that all theothers have chosen.四、简述题（共2小题，每题9分，共18分）1 What are the fundamental assumptions of perfect competitive market? (1)Sellers are price takers. There are two aspects of this assumption. First, each individual supplier believes that its output choice has a negligible direct effect on the market price; a change in its output level has little effect on the price when all other suppliers hold their output levels constant. Second, each supplier believes it has no effect on the collective actions of other suppliers.(2)Sellers do not behave strategically. The supplier does not anticipate any reactions by rival suppliers when it choose its own actions.(3)Entry into the market is free. When the supplier can enter a market without incurring any special costs, that market is said to be characterized by free entry. Clearly, whether entry is blocked or free has an important effect on the nature of market equilibrium. The perfectly competitive model is based on the assumption that there are no impediments to entry.(4)Buyers are price takers. In a competitive market, each buyer(whether a firm or a household) believes that it can purchase as much as it wishes to at the going price without having any effect on that price.2. Emily has decided always to spend one-third of her income on clothing.a. What is her income elasticity of clothing demand?b. What is her price elasticity of clothing demand?a.If Emily always spends one-third of her income on clothing, then her income elasticity of demand is one, since maintaining her clothing expenditures as a constant fraction of her income means the percentage change in her quantity of clothing must equal her percentage change in income. For example, suppose the price of clothing is $30, her income is $9,000, and she purchases 100 clothing items. If her income rose 10 percent to $9,900, shed spend a total of $3,300 on clothing, which is 110 clothing items, a 10 percent increase. b.Emilys price elasticity of clothing demand is also one, since every percentage point increase in the price of clothing would lead her to reduce her quantity purchased by the same percentage. Again, suppose the price of clothing is $30, her income is $9,000, and she purchases 100 clothing items. If the price of clothing rose 1 percent to $30.30, she would purchase 99 clothing items, a 1 percent reduction. 五、计算题（共3小题，每小题9分，共27分）1 Suppose that your demand schedule for compact discsis as follows:PRICEQUANTITY DEMANDED(INCOME = $10,000) QUANTITY DEMANDED(INCOME = $12,000) $8405010324512243014162016812a. Use the midpoint method to calculate your price elasticity of demand as the price of compact discs increases from $8 to $10 if (i) your income is $10,000, and (ii) your income is $12,000.b. Calculate your income elasticity of demand as your income increases from $10,000 to $12,000 if (i) the price is $12, and (ii) the price is $16.a.If your income is $10,000, your price elasticity of demand as the price of compact discs rises from $8 to $10 is (40 - 32)/36/(10 - 8)/9 =0.22/0.22 = 1. If your income is $12,000, the elasticity is (50 - 45)/47.5/(10 - 8)/9 = 0.11/0.22 = 0.5.b.If the price is $12, your income elasticity of demand as your income increases from $10,000 to $12,000 is (30 - 24)/27 / (12,000 - 10,000)/11,000 = 0.22/0.18 = 1.22. If the price is $16, your income elasticity of demand as your income increases from $10,000 to $12,000 is (12 - 8)/10 / (12,000 - 10,000)/11,000 = 0.40/0.18 = 2.2.2 Suppose a firm has got such short run cost functioin: TC(Q)=Q3-10Q2+17Q+66.(1) Is the firms production in the short run or long run? why?(2) What is TVC(Q)? (3) What is AVC(Q)? (4) What is AFC(Q)? (5) What is MC(Q)?(1)The firms production is in the short run. Because there is fixed cost 66, which doesnt change with the quantity of output.(2)TVC(Q)= Q3-10Q2+17Q (3)AVC(Q)= Q2-10Q+17(4) AFC(Q)= 66/Q (5) MC(Q)=3Q2-20Q+173 Ernie owns a water pump. Because pumping large amounts of water is harder than pumping small amounts, the cost of producing a bottle of water rises as he pumps more. Here is the cost he incurs to produce each bottle of water: Cost Cost of first bottle $1Cost of second bottle 3Cost of third bottle5Cost of fourth bottle7a. From this information, derive Ernies supply schedule. Graph his supply curve for bottled water.b. If the price of a bottle of water is $4, how many bottles does Ernie produce and sell? How much producer surplus does Ernie get from these sales? Show Ernies producer surplus in your graph.c. If the price rises to $6, how does quantity supplied change? How does Ernies producer surplus change? Show these changes in your graph.a.Ernies supply schedule for water is:PriceQuantity SuppliedMore than $74$5 to $73$3 to $52$1 to $31Less than $10Ernies supply curve is shown in Figure 10.b.When the price of a bottle of water is $4, Ernie sells two bottles of water. His producer surplus is shown as area A in the figure. He receives $4 for his first bottle of water, but it costs only $1 to produce, so Ernie has producer surplus of $3. He also receives $4 for his second bottle of water, which costs $3 to produce, so he has producer surplus of $1. Thus Ernies total producer surplus is $3 + $1 = $4, which is the area of A in the figure.c.When the price of a bottle of water rises from $4 to $6, Ernie sells three bottles of water, an increase of one. His producer surplus consists of both areas A and B in the figure, an increase by the amount of area B. He gets producer surplus of $5 from the first bottle ($6 price minus $1 cost), $3 from the second bottle ($6 price minus $3 cost), and $1 from the third bottle ($6 price minus $5 price), for a total producer surplus of $9. Thus producer surplus rises by $5 (which is the size of area B) when the price of a bottle of water rises from $4 to $6.江西农业大学Microeconomics试卷B答案(本试题要求考生尽量用英文回答；如部分考生由于英语水平有限，有的题目用中文答题，也可酌情给分)一、选择题：（共15小题，每小题2分，共30分）1.A 2.B 3.D 4.B 5.C 6.A 7.C 8.D 9.C 10.C 11.B 12.D 13.B 14.D 15.A 二、判断对错：（共10小题，每小题1分，共10分）1.T 2.F 3.F 4.T 5.T 6.T 7.F 8.F 9.F 10.T 三、名词解释（共5小题，每小题3分，共15分）1. Price Elasticity of Demand: Measures the percentage change in quantitydemanded for a one percent change in price, ceteris paribus.2 Marginal Cost: MC is the change in total cost due to the production ofone more unit of output.3. Opportunity cost: the value of the most highly valued forgone alternative4.Consumer surplus:The difference between what a consumer is willing topay and what she has to pay.5. A Nash equilibrium is a situation in which economic actors interactingwith one another each choose their best strategy given the strategies that all theothers have chosen.四、简述题（共2小题，每题9分，共18分）1 What are the fundamental assumptions of perfect competitive market? (1)Sellers are price takers. There are two aspects of this assumption. First, each individual supplier believes that its output choice has a negligible direct effect on the market price; a change in its output level has little effect on the price when all other suppliers hold their output levels constant. Second, each supplier believes it has no effect on the collective actions of other suppliers.(2)Sellers do not behave strategically. The supplier does not anticipate any reactions by rival suppliers when it choose its own actions.(3)Entry into the market is free. When the supplier can enter a market without incurring any special costs, that market is said to be characterized by free entry. Clearly, whether entry is blocked or free has an important effect on the nature of market equilibrium. The perfectly competitive model is based on the assumption that there are no impediments to entry.(4)Buyers are price takers. In a competitive market, each buyer(whether a firm or a household) believes that it can purchase as much as it wishes to at the going price without having any effect on that price.2. Emily has decided always to spend one-third of her income on clothing.a. What is her income elasticity of clothing demand?b. What is her price elasticity of clothing demand?a.If Emily always spends one-third of her income on clothing, then her income elasticity of demand is one, since maintaining her clothing expenditures as a constant fraction of her income means the percentage change in her quantity of clothing must equal her percentage change in income. For example, suppose the price of clothing is $30, her income is $9,000, and she purchases 100 clothing items. If her income rose 10 percent to $9,900, shed spend a total of $3,300 on clothing, which is 110 clothing items, a 10 percent increase. b.Emilys price elasticity of clothing demand is also one, since every percentage point increase in the price of clothing would lead her to reduce her quantity purchased by the same percentage. Again, suppose the price of clothing is $30, her income is $9,000, and she purchases 100 clothing items. If the price of clothing rose 1 percent to $30.30, she would purchase 99 clothing items, a 1 percent reduction. 五、计算题（共3小题，每小题9分，共27分）1. a.If your income is $10,000, your price elasticity of demand as the price of compact discs rises from $8 to $10 is (40 - 32)/36/(10 - 8)/9 =0.22/0.22 = 1. If your income is $12,000, the elasticity is (50 - 45)/47.5/(10 - 8)/9 = 0.11/0.22 = 0.5.b.If the price is $12, your