CHAPTER
1
The Scope and Method of
Economics
Prepared by: Fernando Quijano
and Yvonn Quijano
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
如何唸這本原文書
• 約略瞭解章節內容 : 每章開始的右上方 ( p.1 )
• 讀每節得內容 : 每頁的左或右邊之方塊為其重要
的解釋名詞 要弄清楚。
• SUMMARY : ( p.16 )
• REVIEW TERMS AND CONCEPTS : ( p.16 )
• PROBLEM SET : ( p.17 )
• WEB EXERCISES : ( P.17 )
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
第一章
經濟學的範圍與方法
• Why Study Economics ?
To Learn a Way of Thinking
Understand Society
Understand Global Affairs
an informed Voter
To
To
To Be
• The Scope of Economics
Microeconomics and Macroeconomics
The Diverse Fields of Economics
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
第一章
經濟學的範圍與方法
• The Method of Economics
Theories and Models
Economic Policy
• An Invitation
• Appendix :
How to Read and Understand Graphs
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
The Study of Economics
• Economics is the study of
how individuals and societies
choose to use the scarce
resources that nature and
previous generations have
provided. ( p.2 )
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
經 濟 的 研 究
• 經濟學的定義:
經濟學是研究個人與社會如何選擇去應用大自然
與前人所提供的稀少性資源。
經濟學是研究人類如何選擇具有多種用途的稀少
性資源去生產財貨與勞務，以滿足人類無窮慾望
的一門社會科學。
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
Why Study Economics?
• Probably the most important reason
for studying economics is to learn
a way of thinking.
• Three fundamental concepts:
• Opportunity cost
• Marginalism, and
• Efficient markets
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
一、 為 何 學 習 經 濟 學
A. 學習經濟學最重要的理由是學習~思考的方法~
1. 三個基本的概念:
a.機會成本
b.邊際主義
c.效率市場
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
Opportunity Cost
• Opportunity cost is the best
alternative that we forgo, or give
up, when we make a choice or a
decision. ( P.2 )
• Opportunity costs arise because
time and resources are scarce.
Nearly all decisions involve tradeoffs.
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
機 會 成 本
• 機會成本 : 是當我們做一種選擇或決策時所相對
放棄的最佳方案。
• 由於時間與資源是稀少的…此產生了機會成本
• 幾乎所有的決策都包含著 trade-off 互換的關係
• 例:
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
Marginalism
• In weighing the costs and benefits of a decision,
it is important to weigh only the costs and
benefits that arise from the decision.
• For example, when deciding whether to produce
additional output, a firm considers only the
additional (or marginal cost), not the sunk cost.
• Sunk costs are costs that cannot be avoided,
regardless of what is done in the future, because
they have already been incurred.
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
邊際的概念
每增加一單位的 X 所引起 Y 的變動量
如 : 邊際效用 ; 邊際產量 ; 邊際成本 ; 邊際收益 …..
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
Efficient Markets
• An efficient market is one in which
profit opportunities are eliminated
almost instantaneously. (P.3 )
• There is no free lunch! Profit
opportunities are rare because, at
any one time, there are many
people searching for them.
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
效率市場
• 效率市場 : 是幾乎沒有利潤的機會
There is no free lunch ! 天下沒有白吃的午餐!
因為在任何一個時間下，利潤的機會幾乎是少有
的，只因有許多人在尋找他。
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
More Reasons to Study Economics
• Economics involves the study of societal and
global affairs concerning resource allocation.
• Economics is helpful to us as voters. Voting
decisions require a basic understanding of
economics.
• Money and financial systems are an important
component of the economic system, but are not
the most fundamental issue in economics.
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
更多的理由學習經濟學
B. 經濟學包含社會與全球事務有關資源分配的研究
C. 經濟學幫助我們成為一個投票者。
投票的決定需要對經濟學有基本的認識。
貨幣與金融制度在經濟體系中重要部份的一環，
但不是經濟學中最基本的問題。
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
The Scope of Economics
• Microeconomics is the branch of economics
that examines the functioning of individual
industries and the behavior of individual
decision-making units—that is, business firms
and households. ( p.7 )
• Macroeconomics is the branch of economics
that examines the economic behavior of
aggregates— income, output, employment, and
so on—on a national scale. ( p.7 )
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
二、 經 濟 學 的 範 圍
A. 個體經濟學與總體經濟學
1.個體經濟學 :
是經濟學的一分支，為檢視個別廠商的功能與
個人下決策的行為。
換言之，就是企業與家計單位
2.總體經濟學 :
是經濟學的一分支，為檢視總合— 所得、產出量、就業
等等---一國規模的經濟行為。
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
B. The Diverse Fields of Economics
(p.8)
Examples of microeconomic and macroeconomic concerns
Microeconomics
Macroeconomics
Production
Prices
Income
Employment
Production/Output
in Individual
Industries and
Businesses
Price of Individual
Goods and Services
Distribution of
Income and Wealth
How much steel
How many offices
How many cars
Price of medical
care
Price of gasoline
Food prices
Apartment rents
Wages in the auto
industry
Minimum wages
Executive salaries
Poverty
Employment by
Individual
Businesses &
Industries
Jobs in the steel
industry
Number of
employees in a firm
National
Production/Output
Aggregate Price
Level
National Income
Total wages and
salaries
Employment and
Unemployment in
the Economy
Total Industrial
Output
Gross Domestic
Product
Growth of Output
Consumer prices
Producer Prices
Rate of Inflation
Total corporate
profits
Total number of
jobs
Unemployment
rate
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
B. 經 濟 學 的 各 種 範 圍
Examples of microeconomic and macroeconomic concerns
Microeconomics
Macroeconomics
Production
Prices
Income
Employment
Production/Output
in Individual
Industries and
Businesses
Price of Individual
Goods and
Services
Distribution of
Income and
Wealth
How much steel
How many offices
How many cars
Price of medical
care
Price of gasoline
Food prices
Apartment rents
Wages in the auto
industry
Minimum wages
Executive salaries
Poverty
Employment by
Individual
Businesses &
Industries
Jobs in the steel
industry
Number of
employees in a
firm
National
Production/Output
Aggregate Price
Level
National Income
Total wages and
salaries
Employment and
Unemployment in
the Economy
Total Industrial
Output
Gross Domestic
Product
Growth of Output
Consumer prices
Producer Prices
Rate of Inflation
Total corporate
profits
Total number of
jobs
Unemployment
rate
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
The Method of Economics
• Normative economics, also called policy
economics, analyzes outcomes of economic
behavior, evaluates them as good or bad, and
may prescribe courses of action. ( p.8 )
• Positive economics studies economic
behavior without making judgments. It
describes what exists and how it works. (p.8 )
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
三、 經 濟 學 的 方 法
A.規範與實證 :
1.規範 (唯善) 經濟學 : 又稱政策經濟學，分析經濟，
行為的結果，評估他們的好壞同時指示其行動的
趨勢。
做`價值的判斷` 指出 `應該如何` 的經濟學
2. 實證 (唯真) 經濟學 : 研究不做判斷的經濟行為，
敘述事實與其運作的現象。
陳述事實，指出 `是如何` 的經濟學
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
The Method of Economics
• Positive economics includes:
• Descriptive economics, which involves the
compilation of data that describe phenomena and
facts. ( p.8 )
• Economic theory that involves building models of
behavior. A theory is a statement or set of related
statements about cause and effect, action and
reaction. ( p.10 )
• Empirical economics refers to the collection
and use of data to test economic theories.(p.12)
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
經濟學的方法
•
實證經濟學包括 :
a. 敘述經濟學 :包括描述現象與事實之資料的編輯
b. 經濟理論 : 包括行為模型的建立，討論起因與
結果及行動與反映的敘述或相關的一堆敘述
B.驗證經濟學 :
利用資料的應用與收集來檢視經濟理論。
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
Theories and Models
• A theory is a general statement of cause and
effect, action and reaction. Theories involve
models, and models involve variables. ( p.10 )
• A model is a formal statement of a theory.
Models are descriptions of the relationship
between two or more variables. ( p.10 )
• Ockham’s razor is the principle that irrelevant
detail should be cut away. Models are
simplifications, not complications, of reality.(p.10)
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
理論與模型
• 理論 : 是原因與結果 行動與反應 的一般敘述
• 模型 : 是一個理論的前引敘述 說明了兩個或多
個變數間的關係
• Ockham 剃刀 : 是將不相關的細節去除的一個原
則 模型是現實生活的簡化而不是複雜化
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
Theories and Models
• A variable is a measure that can change from
observation to observation. ( p.10 )
• Using the ceteris paribus, or all else equal,
assumption, economists study the relationship
between two variables while the values of other
variables are held unchanged. ( p.11 )
• The ceteris paribus device is part of the process
of abstraction used to focus only on key
relationships.
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
C. 理 論 與 模 型
1.變數是一種測度 他隨著觀測的變動而改變
2.應用假設其他情況不變 ( ceteris paribus, all else
equal, assumption ),即當其他變數值不變的情況
下 經濟學家研究兩個變數間的關係
3.`假設其他情況不變 ` ( ceteris paribus ) 是用來集
中在某一變數的探討上
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
Theories and Models
• In formulating theories and models we must
avoid two pitfalls:
• The Post Hoc Fallacy: It is erroneous to believe that
if event A happened before event B, then A caused B.
( p.11 )
• The Fallacy of Composition: It is erroneous to
believe that what is true for a part is also true for the
whole. Theories that seem to work well when applied
to individuals often break down when they are applied
to the whole. (p. 12 )
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
理論與模型
• 在建立理論與模型時 我們必須避免兩種謬誤 :
• 因果謬誤 ( Post Hoc Fallacy ) : 很多人誤信
當 A 事件發生在B 事件之前就誤認為 A 引起 B
• 合成謬誤 ( Fallacy of Composition ) : 人們誤信
單一事件是如此則整體是件亦是如此
當理論應用在個人管用時 往往應用在全數時卻
不管用
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
Economic Policy
Criteria for judging economic outcomes:
• Efficiency, or allocative efficiency. An efficient
economy is one that produces what people want
at the least possible cost. ( p.13 )
• Equity, or fairness of economic outcomes. ( p.15 )
• Growth, or an increase in the total output of an
economy. ( p.15 )
• Stability, or the condition in which output is steady
or growing, with low inflation and full employment
of resources. ( p.15 )
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
D. 經 濟 政 策
判斷經濟結果的種類如下 :
1.效率 或 分配效率 : 具有效率的經濟是以最低可能
的成本來生產人們所需要的。
2.公正 或 經濟結果的公平。
3.成長 或 一個經濟體系總產出量的增加。
4.穩定 或 在低通貨膨脹與資源充分就業下 產出量
是穩定或成長的狀況 。
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
How to Read and Understand Graphs
( p.18 )
• Each point on the Cartesian
plane is a combination of
(X,Y) values.
• The relationship between X
and Y is causal. For a given
value of X, there is a
corresponding value of Y, or
X causes Y.
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
幾何圖形
• 在經濟學的討論中，幾何圖形為一非常重要的輔
助工具。簡單的圖形可用來清楚的解釋經濟現象
或行為。故對圖形的認知與了解在經濟學中就變
得非常重要。無論如何，清楚圖形的意義，在學
經濟學的過程中會有事半功倍之效果。
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
Reading Between the Lines
• A line is a continuous string
of points, or sets of (X,Y)
values on the Cartesian
plane.
• The relationship between X
and Y on this graph is
negative. An increase in the
value of X leads to a
decrease in the value of Y,
and vice versa.
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
Positive and Negative Relationships
An upward-sloping line
describes a positive
relationship between X
and Y.
A downward-sloping
line describes a
negative relationship
between X and Y.
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
The Components of a Line
• The algebraic expression of
this line is as follows:
Y = a + bX
b=
Y
X

Y1  Y0
X1  X0
© 2002 Prentice Hall Business Publishing
where:
Y = dependent variable
X = independent variable
a = Y-intercept, or value of
Y when X = 0.
+ = positive relationship
between X and Y
b = slope of the line, or the
rate of change in Y
given a change in X.
Principles of Economics, 6/e
Karl Case, Ray Fair
Different Slope Values
b
5
10
b
b 
 0.5
0
10
 0
© 2002 Prentice Hall Business Publishing
b
Principles of Economics, 6/e
7
10
10
0
  0 .7
 
Karl Case, Ray Fair
Strength of the Relationship Between
X and Y
• This line is relatively flat.
Changes in the value of X have
only a small influence on the
value of Y.
• This line is relatively steep.
Changes in the value of X have a
greater influence on the value of
Y.
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair
The Difference Between a Line and a Curve
Equal increments in
X lead to constant
increases in Y.
© 2002 Prentice Hall Business Publishing
Equal increments in
X lead to diminished
increases in Y.
Principles of Economics, 6/e
Karl Case, Ray Fair
Interpreting the Slope of a Curve
• Graph A has
a positive and
decreasing
slope.
• Graph B has
a negative
slope, then a
positive slope.
• Graph C shows
a negative and
increasing
relationship
between X and
Y.
• Graph D
shows a
negative and
decreasing
slope.
© 2002 Prentice Hall Business Publishing
Principles of Economics, 6/e
Karl Case, Ray Fair