Final exam
Microeconomics
Dr. Chien-Ho Wang
January 12, 2015
期中考為關書考試, 做弊以零分計算. 請於考試時關閉手機. 此考試可攜帶計算
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作答. 做答時請對所有題目詳列作答理由及計算步驟, 理由及步驟不清不予記分.
請將答案及作答理由寫在答案卷上, 未寫於答案卷上則不予計分. (題目共 6 頁.)
題目隨答案卷繳回 請在兩份考卷 (題目卷及答案卷)寫上姓名.
姓名:
系級:
學號:
一、選擇題 (60%; 單選, 每題 5 分)
1. The total cost (TC) of producing computer APPLE i-pad (Q) is given as: TC = 200
+ 5Q. What is the average variable cost?
(a). 500
(b). 5
(c). 5Q
(d). 5 + (200/Q)
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2. The LAC and LMC curves in the diagram below are consistent with a production
function that exhibits
(a). decreasing returns to scale.
(b). increasing returns to scale.
(c). decreasing returns to scale for small levels of output, then constant returns to
scale, and eventually increasing returns to scale as output increases.
(d). increasing returns to scale for small levels of output, then constant returns to
scale, and eventually decreasing returns to scale as output increases.
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3. Consider the following diagram where a perfectly competitive firm faces a price of
$40.
MC
AC
D
AVC
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Figure 1
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Refer to Figure 1. At the profit-maximizing level of output, total profit is
(a). $603.
(b). -$120.
(c). $432.
(d) $600.
4. An industry has 1000 competitive firms, each producing 50 tons of output. At the
current market price of $10, half of the firms have a short run supply
curve with a slope of 1; the other half each have a short run supply
curve with slope 2. The short run elasticity of market supply is
(a).1/50
(b).1/5
(c). 3/20
(d). 2/5
5.
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Refer to Figure 9.2. At price 0H and quantity Q1, the deadweight loss is
(a). DGC.
(b). BDC.
(c). 0FGQ1.
(d). BGC.
6.
The above figure shows the demand and cost curves facing a monopoly. If the firm is
a profit maximizer, its Lerner Index will equal
(a) 1.
(b) 1/3.
(c). 1.5.
(d). 3.
7. A perfect-price-discriminating monopoly's marginal revenue curve
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(a). is the demand curve.
(b). lies below the demand curve.
(c). varies for each consumer.
(d). is the same as the monopolist's marginal revenue curve.
8. Multimarket Price Discrimination
Bob is the only carpet installer in a small isolated town. The above figure shows the
demand curves of two distinct groups of customers-residential and business. If the
marginal cost of installing carpet is a constant $1 per sq yard, what price does Bob
charge each segment?
(a). $1 in each market
(b). $1 in the residential market and $5 in the business market
(c). $5.50 in the residential market and $8 in the business market
(d). $10 in the residential market and $15 in the business market
9. If a cartel is unable to monitor its members and punish those firms that violate the
agreement, then
(a). the member firms will each act as price setters.
(b). the cartel will prosper in the long run.
(c). the market will become a monopoly.
(d). the cartel will fail.
10. The Bertrand model of price setting assumes that a firm chooses its price
(a). subject to what price rival firms are charging.
(b). independently of what price other firms charge.
(c). so that joint profits are maximized.
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(d). without considering the shape of the demand curve.
11. When neither player has a dominant strategy
(a). game theory will not provide information.
(b). no Nash-Equilibrium exists.
(c). at least one Nash-Equilibrium exists.
(d). the game cannot be analyzed.
12. In the long run, a monopolistically competitive firm
(a). produces at minimum average cost.
(b). earns zero economic profit.
(c). operates at full capacity.
(d). All of the above.
二、計算問答題 (40%; 各題配分如題示.)
1. Suppose the demand for pizza in a small isolated town is p = 10 - Q. There are only
two firms,A and B. Each has a cost function TC = 2 + Q.
(a). (10%) Determine the equilibrium quantities of each if firm A is the Stackelberg
leader.
(b). (10%) Compare the firms' profits if they behave as Cournot duopolists
2. Suppose Ralph hires workers at his supermarket at a wage of $12/hour. Ralph
currently has 10 checkstands (i.e., capital) with a rental rate of $10/hour. Production
of customers served (i.e., output) is determined by the hourly production function
f ( L, K )  (1/ 2) L3 / 4 K 2
For the questions that follow, the number of checkstands is fixed. Show your work
clearly.
(a). (10%) If Ralph wants to serve 400 customers per hour, how many workers must
he employ? How much will it cost to serve 400 customers per hour?
(b). (10%) Derive Ralph’s short-run cost function with the 10 checkstands.
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