北大微观经济学课件(英文版)Ch23_Industry_Supply
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北大微观经济学课件(英文版)ch3 Preferences
中级微观经济学
Assumptions about Preference Relations
Transitivity
(传递性): If x is at least as preferred as y, and y is at least as preferred as z, then x is at least as preferred as z; i.e.
x1
2012-10-9 中级微观经济学
Indifference Curves Exhibiting Satiation
x2
Satiation (bliss) point Better
2012-10-9
中级微观经济学
Extreme Cases of Indifference Curves; Perfect Substitutes
x2
15 I2 8 Slopes are constant at - 1.
I1
Bundles in I2 all have a total of 15 units and are strictly preferred to all bundles in I1, which have a total of only 8 units in them. x1 8 15
x
f y and y f z ~ ~
x f z.
~
2012-10-9
中级微观经济学
Indifference Curves
Take
a reference bundle x’. The set of all bundles equally preferred to x’ is the indifference curve containing x’; the set of all bundles y ~ x’. Since an indifference “curve” is not always a curve a better name might be an indifference “set”.
微观经济学英文课件Ch
– 着眼于推动技术进步的政府对经济的干预政策成为技术 政策。
• Patent laws are a form of technology policy that give the individual (or firm) with patent protection a property right over its invention.
Examples of Negative Externalities 负的外部性的例子
• Automobile exhaust • Cigarette smoking • Barking dogs (loud pets) • Loud stereos in an apartment building • Stinky Toufu
Pollution and the Social Optimum...
Price of Aluminum
Cost of pollution
Social cost
Supply
(private cost)
Optimum
Equilibrium
Demand
(private value)
0
Qoptimum QMARKE
0
QMARKET QOPTIMUM
Quantity of Robots
Positive Externalities in Production
• The intersection of the demand curve and the social-cost curve determines the optimal output level.
T
Quantity of Aluminum
Negative Externalities in Production 生产中的负的外部性
• Patent laws are a form of technology policy that give the individual (or firm) with patent protection a property right over its invention.
Examples of Negative Externalities 负的外部性的例子
• Automobile exhaust • Cigarette smoking • Barking dogs (loud pets) • Loud stereos in an apartment building • Stinky Toufu
Pollution and the Social Optimum...
Price of Aluminum
Cost of pollution
Social cost
Supply
(private cost)
Optimum
Equilibrium
Demand
(private value)
0
Qoptimum QMARKE
0
QMARKET QOPTIMUM
Quantity of Robots
Positive Externalities in Production
• The intersection of the demand curve and the social-cost curve determines the optimal output level.
T
Quantity of Aluminum
Negative Externalities in Production 生产中的负的外部性
[北大微观经济学课件]Ch22 Firm Supply
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pe y’
MCs(y)
ys*
y
The Firm’s Short-Run Supply Decision
$/output unit
pe
At y = ys*, p = MC and MC slopes upwards. y = ys* is
profit-maximizing.
MCs(y)
y’
ys*
y
The Firm’s Short-Run Supply Decision
Market Environments
Are there many other firms, or just a few?
Do other firms’ decisions affect our firm’s payoffs?
Is trading anonymous, in a market? Or are trades arranged with separate buyers by middlemen?
s (y) py cs (y) py F cv (y).
If the firm chooses y = 0 then its profit is
Pure Competition
$/output unit
p’ pe p”
Market Demand
Y
Smallness
What does it mean to say that an individual firm is “small relative to the industry”?
Smallness
Market Environments
Dominant Firm: Many firms, but one much larger than the rest. The large firm’s decisions affect the payoffs of each small firm. Decisions by any one small firm do not noticeably affect the payoffs of any other firm.
微观经济学英文版PPT课件
Or, the opportunity cost that use a certain resource is the highest price of abandoning other uses of this resource
10
2.2 the definition of microeconomics
The starting point of economics searching The definition of Microeconomics People how to make decision Why need to bargain Why need to build market economics
Economics is a study, learning selection of scarce resources with different uses; The goal is effective allocation of scarce resources to produce goods and services, and in the present or future, let them reasonable allocated to social members or group for consumption.
8
Production possibilities curve
PPC is a graph that shows the combinations of output that the economy can possibly produce given the available factors of production and the available production technology.
10
2.2 the definition of microeconomics
The starting point of economics searching The definition of Microeconomics People how to make decision Why need to bargain Why need to build market economics
Economics is a study, learning selection of scarce resources with different uses; The goal is effective allocation of scarce resources to produce goods and services, and in the present or future, let them reasonable allocated to social members or group for consumption.
8
Production possibilities curve
PPC is a graph that shows the combinations of output that the economy can possibly produce given the available factors of production and the available production technology.
微观经济学英文版精品PPT课件
Chapter 1: The Fundamentals of Economics（A. Introduction）
1.2 Microeconomics and Macroeconomics
What is Microeconomics ?
It is concerned with the behavior of individual entities such as markets, firms and households.
You want to buy a computer which is $2510. while it is $2500 in the supermarket in downtown. Wherever you buy the computer, it would return to the producer if there is any problem. Where would you buy it？
There are three types of economies:
Market economy Command economy Mixed economy
Chapter 1: The Fundamentals of Economics (C. Society’s technological possibilities)
Chapter 1: The Fundamentals of Economics（A. Introduction）
1.1 Scarcity and Efficiency
What is economics ?
Economics is the study f how societies use scarce resources to produce valuable commodities and distribute them among different people.
微观经济学课件中英文13
The amount that the firm receives for the sale of its output. 企业销售产品所得
Total Cost 总成本
The market value of the inputs a firm uses in production.
企业用于生产的投入要素的市场价值。
• Implicit costs are input costs that do not require an outlay of money by the firm.
Harcourt, Inc. items and derived items copyright © 2001 by Harcourt, Inc.
Profit = Total revenue - Total cost 利润＝总收入－总成本
Harcourt, Inc. items and derived items copyright © 2001 by Harcourt, Inc.
Costs as Opportunity Costs
A firm’s cost of production includes all the opportunity costs of making its output of goods and services. Explicit and Implicit Costs
WHAT ARE COSTS?
The Firm’s Objective
The economic goal of the firm is to maximize profits.
Harcourt, Inc. items and derived items copyright © 2001 by Harcourt, Inc.
Total Cost 总成本
The market value of the inputs a firm uses in production.
企业用于生产的投入要素的市场价值。
• Implicit costs are input costs that do not require an outlay of money by the firm.
Harcourt, Inc. items and derived items copyright © 2001 by Harcourt, Inc.
Profit = Total revenue - Total cost 利润＝总收入－总成本
Harcourt, Inc. items and derived items copyright © 2001 by Harcourt, Inc.
Costs as Opportunity Costs
A firm’s cost of production includes all the opportunity costs of making its output of goods and services. Explicit and Implicit Costs
WHAT ARE COSTS?
The Firm’s Objective
The economic goal of the firm is to maximize profits.
Harcourt, Inc. items and derived items copyright © 2001 by Harcourt, Inc.
[北大微观经济学课件]Ch22 Firm Supply-文档资料
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$/output unit
Market Supply
p’
pe
At a price of p’, zero is
demanded from the firm.
p”
Market Demand
y At a price of p” the firm faces the entire market demand.
Pure Competition
$/output unit
p’ pe p”
Market Demand
Y
Smallness
What does it mean to say that an individual firm is “small relative to the industry”?
Smallness
This chapter explores only pure competition.
Pure Competition
A firm in a knows it has no influence over the market price for its product. The firm is a market price-taker.
The Firm’s Short-Run Supply Decision
$/output unit
pe y’
At y = ys*, p = MC and MC slopes upwards. y = ys* is
profit-maximizing.
So a profit-max.
supply level
(b) ys* = 0: (y)
ds(y) dy
pMCs(y)0
at yy*s 0.
Market Supply
p’
pe
At a price of p’, zero is
demanded from the firm.
p”
Market Demand
y At a price of p” the firm faces the entire market demand.
Pure Competition
$/output unit
p’ pe p”
Market Demand
Y
Smallness
What does it mean to say that an individual firm is “small relative to the industry”?
Smallness
This chapter explores only pure competition.
Pure Competition
A firm in a knows it has no influence over the market price for its product. The firm is a market price-taker.
The Firm’s Short-Run Supply Decision
$/output unit
pe y’
At y = ys*, p = MC and MC slopes upwards. y = ys* is
profit-maximizing.
So a profit-max.
supply level
(b) ys* = 0: (y)
ds(y) dy
pMCs(y)0
at yy*s 0.
微观经济学双语课件
1.2 ECONOMICS: A SOCIAL SCIENCE
Goal of economists is to discover how the economic world works. Economists distinguish between:
• Positive statements（实证经济学）: What is • Normative statements（规范经济学）: What ought to be The task of economic science:
The condition that arises because the available resources are insufficient to satisfy unlimited wants. Faced with scarcity, we must make choices—we must choose among the available alternatives. The choices we make depend on the incentives we face.
Checkpoint 1.1
1. Give the definition of following statement (1) Scarcity (2) Incentive (3) Economics (4) Microeconomics (5) Macroeconomics 2. Economists studies choice that arise from one fact. What is the fact ? 3. Provide 3 examples of wants in China today that are especially pressing but not satisfied. 4. Provide an examples of an incentive that is like a carrot and one that like a stick.（tax or subsidy ）
《微观经济学microeconomics》英文版全套课件(101页)
X RL {x R : xl 0 for l 1,..., L}
The economic constraint:
px p1x1 ... pL xL w
The Walrasian budget set (Definition 2.D.1)
Bp,w {x RL : px w}
or
u(x* ) xl
pl
px w
Solution: Walrasian demand function x*( p, w)
Utility Maximization -- Example
Example 3.D.1: the transformed Cobb-Douglas Utility Function
Expenditure Function
Expenditure function e( p,u) Min px s.t. u(x) u {x}
Properties: 1. Homogeneous of degree of one in p 2. Strictly increasing in u and nondecreasing in p 3. Concave in p 4. Continuous in p and u
Comparative Statics – Wealth Effects
The consumer’s Engel function x( p, w)
The wealth effect xl ( p, w) / w or Dwx( p, w) Normal goods and inferior goods
A choice rule C(B) B
The weak axiom of revealed preference (WARP): if x is revealed at least as good as y, then y cannot be revealed preferred to x
The economic constraint:
px p1x1 ... pL xL w
The Walrasian budget set (Definition 2.D.1)
Bp,w {x RL : px w}
or
u(x* ) xl
pl
px w
Solution: Walrasian demand function x*( p, w)
Utility Maximization -- Example
Example 3.D.1: the transformed Cobb-Douglas Utility Function
Expenditure Function
Expenditure function e( p,u) Min px s.t. u(x) u {x}
Properties: 1. Homogeneous of degree of one in p 2. Strictly increasing in u and nondecreasing in p 3. Concave in p 4. Continuous in p and u
Comparative Statics – Wealth Effects
The consumer’s Engel function x( p, w)
The wealth effect xl ( p, w) / w or Dwx( p, w) Normal goods and inferior goods
A choice rule C(B) B
The weak axiom of revealed preference (WARP): if x is revealed at least as good as y, then y cannot be revealed preferred to x
北大微观经济学(英文版) ppt课件
A x1
B x2
29
A x2
Edgeworth’s Box
B 1
xB 1
OB
A 2
B 2
OA
ppt课件
A 1
A x1
xB 2
30
Pareto-Improvement
An
allocation of the endowment that improves the welfare of a consumer without reducing the welfare of another is a Pareto-improving allocation. Where are the Pareto-improving allocations?
A 1
A x1
xB 2
33
Pareto-Improvements
Since
each consumer can refuse to trade, the only possible outcomes from exchange are Pareto-improving allocations. But which particular Paretoimproving allocation will be the outcome of trade?
ppt课件
34
x2
xB 1
Pareto-Improvements A
B 1
OB
A 2
B 2
OA The set of Paretoimproving reallocations ppt课件
A 1
A x1
xB 2
35
Pareto-Improvements
北大微观经济学课件(英文版)Ch31 Welfare
z(2) x(3)
x(2) y(3)
2013-8-8
中级微观经济学
Aggregating Preferences
Bill x(1) y(2) z(3)
Rank-order vote results Bertha Bob (low score wins). x-score = 6 No y-score = 6 state is y(1) z(1) z-score = 6 selected!
Manipulating Preferences
Bill x(1) y(2) z(3) (4)
2013-8-8
Bertha Bob y(1) z(2) (3) x(4) z(1) (2) x(3) y(4)
中级微观经济学
These are truthful preferences. Bob introduces a new alternative and then lies. Rank-order vote results. x-score = 8 y-score = 7 z-score = 6
2013-8-8
中级微观经济学
Aggregating Preferences
Bill x(1) y(2) z(3) Bertha Bob y(1) z(2) x(3) z(1) x(2) y(3)
2013-8-8
中级微观经济学
Aggregating Preferences
Bill x(1) y(2) z(3)
Majority Vote Results x beats y
2013-8-8
中级微观经济学
Aggregating Preferences
Bill x y z Bertha Bob y z x z x y
微观经济学第2章PPT课件
总结词
劳动力市场的供需分析是微观经济学中一个重要的 应用领域，它涉及到劳动力的供求关系和工资水平 。
详细描述
劳动力市场的供需分析可以帮助企业和政府了解劳动力的供求 状况和工资水平的变化趋势。通过分析劳动力的供给和需求， 可以预测未来的劳动力市场状况，为企业的人力资源管理提供 依据。同时，政府也可以根据劳动力市场的状况，制定相应的 政策措施，以保障劳动者的权益和提高劳动力市场的效率。
详细描述
公共资源是指那些可供全体社会成员共同使用的资源，如空气、 水、森林等。由于这些资源的所有权和使用权不明确，往往导 致资源的过度开发和浪费。因此，政府需要采取措施，如制定 法规、发放配额等，来管理和保护公共资源。此外，市场机制 也可以发挥一定的作用，如通过排污权交易等手段，来促进企 业减少污染排放。
详细描述
企业需要根据市场需求、成本和竞争状况等因素，制定合理的产品定价策略，以实现利润最大化。常见的市场定价策略包括成 本加成定价、竞争定价和撇脂定价等。这些策略各有优缺点，企业需要根据实际情况选择合适的定价策略。
总结词
公共资源的管理是微观经济学中一个重要的应用领域，它涉及到 如何有效利用和管理公共资源，以实现资源的合理配置和可持续 发展。
02 市场供需理论
需求曲线
01
02
03
定义
需求曲线表示在一定时期 内，消费者在不同价格水 平上愿意并能够购买的商 品数量。
影响因素
消费者收入、相关商品价 格、消费者偏好、预期价 格等。
变动特点
需求曲线向右下方倾斜， 即商品价格下降时，需求 量增加。
供给曲线
定义
供给曲线表示在一定时期 内，生产者在不同价格水 平上愿意并能够提供的商 品数量。
北大中级微观经济学课件ch
生产者决策
1
生产和成本
我们将展示企业如何使用生产函数和边际成本来优化生产和最小化成本。
2
市场组织和竞争力
我们将讨论市场组织的权力与竞争对企业所产生的影响，包括竞争压力和垄断权 力。
3
产业结构变化
我们将深入分析产业组织的结构和变化，包括激烈的竞争和市场的整合。
市场结构
完全竞争市场
我们将研究完全竞争市场的基 本特征，包括价格接近成本、 进入和退出自由。
博弈论初步
博弈理论简介
我们将介绍博弈论的基本框架和应用，以及它如何帮助我们理解和预测人类行为。
混合策略和纳什均衡
我们将深入研究混合策略和纳什均衡，这是博弈理论中基础的概念。
博弈论的实际应用
我们将探讨博弈论的实际应用，包括应用于产业升级、战略决策和投资组合管理。
3 不完美竞争市场的信息
我们将探讨信息不对称如何影响市场运作，以及为什么市场无法使信息更加有效地与买 家和卖家分享。
收入分配与福利政策
收入分配效应
我们将讨论收入分配和财富分配在市场经济中 的作用和影响，以及通过税收和社会福利政策 来提高社会公平性。
赞助与政治租赁
我们将探究政治捐赠和政治竞选如何影响现代 民主国家的经济和政治生态。
北大中级微观经济学课件
这份课件将引导你探索现代微观经济学的基本概念和原则，以及在商业和政 策制定中的应用。
供给与需求
市场价格与供需关系
我们将详细讨论供给和需求的 基本概念和曲线图，并探究价 格的形成方式。
产业循环流模型
我们将使用产业循环流模型， 以一种简洁和容易理解的方式 来描述市场经济的基本运作过 程。
垄断市场
我们将探讨垄断市场的基本特 征和其对资源配置和效率的影 响。
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2015/8/26 中级微观经济学
Y
Long-Run Industry Supply
The Market p Mkt. Demand p MC(y) AC(y) A “Typical” Firm
p3
S3(p) S4(p)
p3
Y
y3*
y
Market supply would shift outwards again.
Short-Run Industry Equilibrium
Firm 1 ACs
MCs
Firm 2
MCs
Firm 3 ACs
MCs ACs
pse
y1*
y1
y2*
y2
y3*
y3
2015/8/26
中级微观经济学
Short-Run Industry Equilibrium
Firm 1 ACs
MCs
Firm 2
2015/8/26 中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) p2 A “Typical” Firm
S3(p)
p2
Y
y2*
y
Market supply shifts outwards.
2015/8/26 中级微观经济学
2015/8/26 中级微观经济学
Long-Run Industry Supply
Positive
economic profit induces
entry. Economic profit is positive when the market price pse is higher than a firm’s minimum av. total cost; pse > min AC(y). Entry increases industry supply, causing pse to fall. When does entry cease?
2015/8/26 中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) A “Typical” Firm
Mkt. Supply
Y
y
Suppose the industry initially contains only two firms.
2015/8/26 中级微观经济学
Short-Run Industry Equilibrium
Short-run industry supply
pse Market demand Yse Y
Short-run equilibrium price clears the market and is taken as given by each firm. 2015/8/26 中级微观经济学
2015/8/26
中级微观经济学
Supply From A Competitive Industry
Since
every firm in the industry is a price-taker, total quantity supplied at a given price is the sum of quantities supplied at that price by the individual firms.
P2 < 0
P3 = 0
y1 y2 y3 y1* y2* y3* Firm 1 wishes Firm 2 wishes Firm 3 is to remain in to exit from indifferent. the industry. the industry. 2015/8/26 中级微观经济学
2015/8/26
中级微观经济学
Short-Run Supply
In
a short-run the number of firms in the industry is, temporarily, fixed. Let n be the number of firms; i = 1, … ,n. Si(p) is firm i’s supply function.
2015/8/26 中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) A “Typical” Firm
S3(p)
p3 p3
Y
y3*
y
Each firm produces less.
2015/8/26 中级微观经济学
2015/8/26 中级微观经济学
Supply From A Competitive Industry
Firm 1’s Supply
p p
Firm 2’s Supply
S1(p)
S2(p)
2015/8/26
中级微观经济学
Supply From A Competitive Industry
Firm 1’s Supply
Long-Run Industry Supply
In
the long-run every firm now in the industry is free to exit and firms now outside the industry are free to enter. The industry’s long-run supply function must account for entry and exit as well as for the supply choices of firms that choose to be in the industry. How is this done?
p p” p
Firm 2’s Supply
p p”
S1(p”)
S1(p)
S2(p”) S2(p)
S1(p”)+S2(p”)
2015/8/26
S(p) = S1(p) + S2(p)
Industry’s Supply 中级微观经济学
Supply From A Competitive Industry
Firm 1’s Supply
p p
Firm 2’s Supply
p
S1(p)
S2(p)
S(p) = S1(p) + S2(p)
2015/8/26
Industry’s Supply 中级微观经济学
Short-Run Industry Equilibrium
In
a short-run, neither entry nor exit can occur. Consequently, in a short-run equilibrium, some firms may earn positive economics profits, others may suffer economic losses, and still others may earn zero economic profit.
2015/8/26
中级微观经济学
Short-Run Supply
In
a short-run the number of firms in the industry is, temporarily, fixed. Let n be the number of firms; i = 1, … ,n. Si(p) is firm i’s supply function. The industry’s short-run supply function is n S(p ) S i (p ). i1
2015/8/26 中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand p MC(y) AC(y) A “Typical” Firm
S3(p)
p3 p3 P>0 y3* y
Each firm’s economic profit is positive. Will another firm enter?
中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) p2 P>0 Y y2* y A “Typical” Firm
p2
Each firm makes a positive economic profit, inducing entry by another firm.
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) p2 A “Typical” Firm
S3(p)
p2Yy2*yMarket supply shifts outwards. Market price falls.
2015/8/26 中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) p2 A “Typical” Firm
p2
Y
y
Then the market-clearing price is p2.
2015/8/26 中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) p2 A “Typical” Firm
Y
Long-Run Industry Supply
The Market p Mkt. Demand p MC(y) AC(y) A “Typical” Firm
p3
S3(p) S4(p)
p3
Y
y3*
y
Market supply would shift outwards again.
Short-Run Industry Equilibrium
Firm 1 ACs
MCs
Firm 2
MCs
Firm 3 ACs
MCs ACs
pse
y1*
y1
y2*
y2
y3*
y3
2015/8/26
中级微观经济学
Short-Run Industry Equilibrium
Firm 1 ACs
MCs
Firm 2
2015/8/26 中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) p2 A “Typical” Firm
S3(p)
p2
Y
y2*
y
Market supply shifts outwards.
2015/8/26 中级微观经济学
2015/8/26 中级微观经济学
Long-Run Industry Supply
Positive
economic profit induces
entry. Economic profit is positive when the market price pse is higher than a firm’s minimum av. total cost; pse > min AC(y). Entry increases industry supply, causing pse to fall. When does entry cease?
2015/8/26 中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) A “Typical” Firm
Mkt. Supply
Y
y
Suppose the industry initially contains only two firms.
2015/8/26 中级微观经济学
Short-Run Industry Equilibrium
Short-run industry supply
pse Market demand Yse Y
Short-run equilibrium price clears the market and is taken as given by each firm. 2015/8/26 中级微观经济学
2015/8/26
中级微观经济学
Supply From A Competitive Industry
Since
every firm in the industry is a price-taker, total quantity supplied at a given price is the sum of quantities supplied at that price by the individual firms.
P2 < 0
P3 = 0
y1 y2 y3 y1* y2* y3* Firm 1 wishes Firm 2 wishes Firm 3 is to remain in to exit from indifferent. the industry. the industry. 2015/8/26 中级微观经济学
2015/8/26
中级微观经济学
Short-Run Supply
In
a short-run the number of firms in the industry is, temporarily, fixed. Let n be the number of firms; i = 1, … ,n. Si(p) is firm i’s supply function.
2015/8/26 中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) A “Typical” Firm
S3(p)
p3 p3
Y
y3*
y
Each firm produces less.
2015/8/26 中级微观经济学
2015/8/26 中级微观经济学
Supply From A Competitive Industry
Firm 1’s Supply
p p
Firm 2’s Supply
S1(p)
S2(p)
2015/8/26
中级微观经济学
Supply From A Competitive Industry
Firm 1’s Supply
Long-Run Industry Supply
In
the long-run every firm now in the industry is free to exit and firms now outside the industry are free to enter. The industry’s long-run supply function must account for entry and exit as well as for the supply choices of firms that choose to be in the industry. How is this done?
p p” p
Firm 2’s Supply
p p”
S1(p”)
S1(p)
S2(p”) S2(p)
S1(p”)+S2(p”)
2015/8/26
S(p) = S1(p) + S2(p)
Industry’s Supply 中级微观经济学
Supply From A Competitive Industry
Firm 1’s Supply
p p
Firm 2’s Supply
p
S1(p)
S2(p)
S(p) = S1(p) + S2(p)
2015/8/26
Industry’s Supply 中级微观经济学
Short-Run Industry Equilibrium
In
a short-run, neither entry nor exit can occur. Consequently, in a short-run equilibrium, some firms may earn positive economics profits, others may suffer economic losses, and still others may earn zero economic profit.
2015/8/26
中级微观经济学
Short-Run Supply
In
a short-run the number of firms in the industry is, temporarily, fixed. Let n be the number of firms; i = 1, … ,n. Si(p) is firm i’s supply function. The industry’s short-run supply function is n S(p ) S i (p ). i1
2015/8/26 中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand p MC(y) AC(y) A “Typical” Firm
S3(p)
p3 p3 P>0 y3* y
Each firm’s economic profit is positive. Will another firm enter?
中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) p2 P>0 Y y2* y A “Typical” Firm
p2
Each firm makes a positive economic profit, inducing entry by another firm.
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) p2 A “Typical” Firm
S3(p)
p2Yy2*yMarket supply shifts outwards. Market price falls.
2015/8/26 中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) p2 A “Typical” Firm
p2
Y
y
Then the market-clearing price is p2.
2015/8/26 中级微观经济学
Long-Run Industry Supply
The Market p Mkt. Demand S2(p) p MC(y) AC(y) p2 A “Typical” Firm