Transcript 高三辛經濟學PPT_Chapter 2

1
Getting Started
CHAPTER CHECKLIST
When you have completed your
study of this chapter, you will be able to
1 Define economics and explain the questions that economists
try to answer.
2 Explain the core ideas that define the economic way of
thinking.
© 2011 Pearson Education
1.1 DEFINITION AND QUESTIONS
All economic questions and problems arise because
human wants exceed the resources available to satisfy
them. 資源有限，慾望無窮
Scarcity 稀少性
Scarcity is the condition that arises because wants
exceeds the ability of resources to satisfy them.
Faced with scarcity, we must make choices
因為稀少，所以需要抉擇
Scarcity Versus Poverty 稀少和貧窮的差異？
1.1 DEFINITION AND QUESTIONS
Economics Defined 決策與抉擇的科學
Economics is the social science that studies the choices
that individuals, businesses, governments, and entire
societies make as they cope with scarcity, the incentives
that influence those choices, and the arrangements that
coordinate them.
Two big economic questions: 兩大基本問題
• How do choices determine what, how, and for
whom goods and services get produced?
• When do choices made in self-interest also
promote the social interest? 自我利益與社會利益是
否一致？
1.1 DEFINITION AND QUESTIONS
What, How, and For Whom? 什麼？如何？為誰？
Goods and services are the objects (goods) and
actions (services) that people value and produce to
satisfy human wants. 這是生產的問題
What goods and services get produced and in what
quantities?
How are goods and services produced?
For Whom are the various goods and services
produced?
1.1 DEFINITION AND QUESTIONS
When Is the Pursuit of Self-Interest in the
Social Interest?
The choices that are best for the individual who
makes them are choices made in the pursuit of
self-interest. 自我利益
The choices that are best for society as a whole are
choices made in the social interest. 社會利益
1.1 DEFINITION AND QUESTIONS
Can choices made in self-interest also serve the
social interest?
自我利益和社會利益是否並轡而行？
Let’s illustrate with seven topics:
可以舉出幾個不同的例子嗎？
何時一致，何時不？
做麵包的？賣餐點的？生產帶來污染的？教書的？
生產加入塑化劑的廠商？混充外國米的廠商？
1.1 DEFINITION AND QUESTIONS
3 The Information-Age Economy
Makers of computer chip and programs
developed products in their self-interest but did
they develop their products in the social interest
at the same time?
4 Disappearing Rainforests and Fish Stocks
When we buy products made with ingredients
from rainforests are we damaging the social
interest?
1.1 DEFINITION AND QUESTIONS
5 Water Shortages
Are the global water resources managed in the
self-interest or in the social interest?
6 Global Warming
The choices we make concerning how to
produce and use energy are made in our selfinterest, but do they serve the social interest?
1.2 THE ECONOMIC WAY OF THINKING
Core Economic Ideas:
• Rational choice 理性選擇
• Cost and Benefit 成本與效益
• Marginal 邊際的概念
• Incentives 誘因的重要
1.2 THE ECONOMIC WAY OF THINKING
Rational Choice
A rational choice is a choice that uses the available
resources to best achieve the objective of the person
making the choice. 假設人是理性的
We make rational choices by comparing costs and
benefits.
理性選擇牽涉成本與效益的比較
1.2 THE ECONOMIC WAY OF THINKING
Cost: What You Must Give Up 須放棄的最低價
Opportunity cost is the best thing that you must
give up to get something—the highest-valued
alternative forgone. 機會成本
Sunk cost is a previously incurred and irreversible
cost. 沈沒成本，就是沒有機會成本時
A sunk cost is not part of the opportunity cost of a
current choice.
成本效益選擇的例子
就成本面而言
假設有三種工作可以選擇
工資都是 50 元
請問選擇哪一個？
願意完成此工作所接受的最高工資，還是最低
工資？
如果願意完成此工作的最低工資都低於 50 元，
你會願意去工作嗎？
選擇心中願意接受的最低工資，經濟意義為何？
1.2 THE ECONOMIC WAY OF THINKING
Benefit: Gain Measured by What You Are
Willing to Give Up 願意放棄的最高價
Benefit is the gain or pleasure that something brings.
On the Margin 在邊際上衡量成本與效益
A choice made on the margin is a choice made by
comparing all the relevant alternatives systematically
and incrementally.
成本效益選擇的例子
就效益面而言
假設有三種餐盒可以選擇
價錢都是 50 元
請問選擇哪一個？
心中願意購買的最高價，還是最低價？
如果願意購買的最高價都低於 50 元，你會購買
嗎？
選擇心中願意出價最高的餐盒，經濟意義為何？
1.2 THE ECONOMIC WAY OF THINKING
Marginal Cost 邊際成本
Marginal cost is the cost of a one-unit increase
in an activity.
Marginal Benefit 邊際效益
Marginal benefit is the what you gain when you
get one more unit of something.
The Marginal Cost and Benefit of Additional RAM
成本效益分析
Optimal Level of Computer Memory
最適的電腦記憶容量
If the marginal benefit is greater than
marginal cost--Increase output
邊際效益大於邊際成本：繼續買
If the marginal benefit is less than the
marginal cost--Decrease output
邊際效益小於邊際成本：減少買
Optimal output is where marginal benefit
equals marginal cost--MB = MC
最適決策點：邊際成本等於邊際效益時
Only pursue an action when MB >= MC, with
positive economic surplus
Fig. 1.2
Falling RAM Prices Increase the Optimal Amount
of Memory
Fig. 1.3
An Increase in the Marginal Benefit of RAM
Increases the Optimal Amount of Memory
大飯店吃Buffet和平常吃飯
的行為比較－如何用模型表示？
吃 buffet 通常都吃到很飽，平常吃飯不至於
吃這麼多，理由是什麼？
便利超商2人經濟學隱含哪些經濟原則？
為何微軟 (MS) 的生產者是最富的人之一
但法拉利的生產者不是？
兩種產品的生產成本有何異同？
1.2 THE ECONOMIC WAY OF THINKING
Making a Rational Choice 理性選擇
When we take those actions for which marginal benefit
exceeds or equals marginal cost. 邊際效益大於邊際成本
Responding to Incentives 對誘因機制反應
An incentive is a reward or a penalty—a “carrot” or a
“stick”—that encourages or discourages an action.
誘因機制，亦即胡蘿蔔與棍子
EYE on WALL STREET
Did Greedy Wall Street Bankers Cause the
Global Economic Slump?
The President has expressed
outrage at the bonuses paid to Wall
Street bankers at the center of the
economic slump.
Isn’t Wall Street’s greed the source
of our economic problems?
Most economists would answer “No.”
Greed is an expression (an extreme one) of self-interest. We
all act in our self-interest. 貪婪和自利近似，只是較為極端
這個世界靠自利動機前進，而不是依賴慈善利他運作。不過，
經濟學眼中的自利動機和慈善利他有相合之處，並非全然互斥
1.2 THE ECONOMIC WAY OF THINKING
Micro and Macro Views of the World
個體經濟學 Microeconomics: The study of the
choices that individuals and businesses make and the
way these choices interact and are influenced by
governments.
總體經濟學 Macroeconomics: The study of the
aggregate (or total) effects on the national economy and
the global economy of the choices that individuals,
businesses, and governments make.
1.2 THE ECONOMIC WAY OF THINKING
Economics as a Social Science
Economists distinguish between
• 實證觀點 Positive statements: What is
• 規範觀點 Normative statements: What ought to be
The task of economic science:
To test positive statements about how the economic world
works and to weed out those that are wrong. Then based
on positive statements to conduct policies with normative
statements
1.2 THE ECONOMIC WAY OF THINKING
Unscrambling Cause and Effect
The central idea that economists use to unscramble
cause and effect is ceteris paribus.
Ceteris paribus means “other things being equal” or
“other things remaining the same.”其他條件不變之下
By changing one factor at a time and holding other
relevant factors constant, we are able to investigate the
effects of the factor.
物理實驗室可以控制各種條件，在真實社會中並不容易
1.2 THE ECONOMIC WAY OF THINKING
In the real world, we observe the outcomes of
simultaneous operation of many factors.
To sort of the effects of each factor, economists use
1. Natural experiments, social experiments 社會實驗
2. Statistical investigations 統計分析
3. Economic experiments 經濟實驗
1. Natural experiments: A situation that arises in the
ordinary course of economic life in which the one factor
of interest is different and other things are equal.例如公
務員有國民旅遊卡，旅遊支出高於私部門受雇人員
1.2 THE ECONOMIC WAY OF THINKING
2. A statistical investigation looks for a correlation.
相關性 Correlation is the tendency for the values of
two variables to move together in a predictable and
related way.
發現教育與所得的相關性還不夠，更要討論因果關係為何？
討論：是高教育帶來高所得，抑或是相反？
3. An economic experiment puts people in a decisionmaking situation and varies the influence of one factor
at a time to discover how they respond.
台灣的受雇者平均薪資所得與教育水準，歷年
林季平、劉千嘉、和張立群 (2008)
1.2 THE ECONOMIC WAY OF THINKING
Economics as Policy Tool
Economics provides a way of approaching problems in
all aspects of our lives: personal, business, and
government.
經濟學作為政策工具，可以協助個人、企業，乃
至政府進行問題評估，並尋求解決辦法