Chap-15垄断(经济学原理-曼昆-中英文双语)

Figure 2 Demand Curves for Competitive and Monopoly Firms
Price
(a) A Competitive Firm
’s Demand Curve
Price
(b) A Monopolist
’s Demand Curve
Demand
Demand
0
Quantity of Output
u Ownership of a key resource. u The government gives a single firm the
exclusive right to produce some good.
u Costs of production make a single producer more efficient than a large number of producers.
A monopolist’s marginal revenue is always
less than the price of its good.
u The demand curve is downward sloping.
u When a monopoly drops the price to sell one more unit, the revenue received from previously sold units also decreases.
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Figure 1 Economies of Scale as a Cause
of Monopoly
作为垄断原因的规模经济
Cost
成本
0
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Government-Created Monopolies
Governments may restrict entry by giving a single firm the exclusive right to sell a particular good in certain markets.
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为什么会产生垄断
进入障碍有三个主要来源:
u 关键资源由一家企业拥有。
u 政府给予一个企业排他性地生产某种产品或劳 务的权利。
u 生产成本使一个生产者比大量生产者更有效 率。
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Natural Monopolies 自然垄断
A natural monopoly arises when there are economies of scale over the relevant range of output. 当相关产量范围内存在规模经济时，自 然垄断就产生了。
ä Competitive Firm
• Is one of many producers
• Faces a horizontal demand curve • Is a price taker
• Sells as much or as little at same price
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Monopoly Resources
Although exclusive ownership of a key resource is a potential source of monopoly, in practice monopolies rarely arise for this reason.
0
Quantity of Output
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图2. 竞争与垄断企业的需求曲线
价格
(a) 一家竞争企业曲线
需求
0
产量
0
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平均总成本 Average total cost
Quantity of Output 产量
HOW MONOPOLIES MAKE PRODUCTION AND PRICING DECISIONS
需求
产量
A Monopoly’s Revenue 垄断者的收益
u Total Revenue 总收益 P x Q = TR
u Average Revenue 平均收益
TR/Q = AR = P
u Marginal Revenue 边际收益
DTR/DQ = MR
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Monopoly 垄断
u A firm is considered a monopoly if . . . it is the sole seller of its product. its product does not have close substitutes.
如果一个企业是其产品唯一的卖者，而且如果 其产品并没有相近的替代品，这个企业就是垄 断者。
$10.00
$8.00
$6.00 $4.00
$2.00
$0.00 -$2.00
-$4.00
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A Monopoly’s Marginal Revenue
Government-Created Monopolies
政府制造的垄断
Patent and copyright laws are two important examples of how government creates a monopoly to serve the public interest. 专利和 版权 是政府如何为公共利益制造垄断 的两个重要例子。
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垄断资源 虽然关键资源的排他性所有权是垄断 的潜在原因，但实际上垄断很少产生 于这种原因。
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Monopoly 垄断
Chapter 15
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Monopoly 垄断
While a competitive firm is a price taker, a monopoly firm is a price maker. 竞争企业是价格接受者，而垄断企业是 价格制定者。
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政府制造的垄断
政府给予一个企业排他性地出售某种物 品或劳务的权利，限制其他企业进入市 场，从而造成垄断。
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垄断的基本原因是进入障碍。
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Why Monopolies Arise Barriers to entry have three sources:
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Natural Monopolies
自然垄断
An industry is a natural monopoly when a single firm can supply a good or service to an entire market at a smaller cost than could two or more firms. 当一个企业能以低于两个或更多企业的成本为整个市场 供给一种物品或劳务时，这个产业就是自然垄断。
垄断者如何作出生产与定价决策
u 垄断与竞争 ä 垄断
• 市场上唯一卖者 • 其需求曲线是向右下方倾斜的 • 价格制定者 • 降低价格才能提高销量
ä 竞争企业
• 是很多生产者当中的一个 • 其需求曲线是水平的 • 是价格接受者 • 在相同价格下想卖多少就卖多少
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Why Monopolies Arise 为什么会产生垄断
The fundamental cause of monopoly is
barriers to entry.
u Monopoly versus Competition
ä Monopoly
• Is the sole producer
• Faces a downward-sloping demand curve
• Is a price maker
• Reduces price to increase sales
$3.00
总收益
(TR=PxQ) $0.00 $10.00 $18.00 $24.00 $28.00 $30.00
$30.00 $28.00
$24.00
平均收益 (AR=TR/Q)
$10.00
$9.00 $8.00
$7.00 $6.00 $5.00 $4.00
$3.00
边际收益
(MR= DTR / D) Q
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垄断者的边际收益
垄断者的边际收益总是小于其物品的价格 。
u 需求曲线是向下倾斜的。
u 当垄断者降低价格增加一个单位销量时， 从以前的产品销售中得到的收益也减少。
Table 1 A Monopoly’s Total, Average, and Marginal Revenue
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表1. 垄断者的总收益、平均收益和边际收益
产量 (Q) 0 1
2
3 4 5 6
7
8
价格
(P)
$11.00 $10.00 $9.00 $8.00
$7.00
$6.00 $5.00 $4.00