CHAPTER CHECKLIST
When you have completed your study of this
chapter, you will be able to
1
Define economics, distinguish between microeconomics and macroeconomics, and explain the
questions of microeconomics.
2
Describe the work of economists as social scientists.
3
Explain five core ideas that define the economic
way of thinking.
4
Explain why economics is worth studying.
1.1 DEFINITIONS AND QUESTIONS
All economic questions and problems arise because
human wants exceed the resources available to satisfy
them.
Scarcity
The condition that arises because the available
resources are insufficient to satisfy 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.
1.1 DEFINITIONS AND QUESTIONS
Incentive
An incentive is a reward or a penalty—a “carrot” or a
“stick”—that encourages or discourages an action.
Economics
The social science that studies the choices that we
make as we cope with scarcity and the incentives that
influence and reconcile our choices.
The subject has two broad divisions—microeconomics
and macroeconomics.
1.1 DEFINITIONS AND QUESTIONS
Microeconomics
Microeconomics: The study of the choices that
individuals and businesses make, the way these
choices interact, and the influence that governments
exert on these choices.
Macroeconomics
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.
1.1 DEFINITIONS AND QUESTIONS
Microeconomic Questions
What?
What goods and services get produced and in what
quantities?
How?
How are goods and services produced?
For Whom?
For whom are the various goods and services
produced?
1.1 DEFINITIONS AND QUESTIONS
Macroeconomic Questions
The three big issues that macroeconomics tries to
understand are:
• The standard of living
• The cost of living
• Economic fluctuations—recessions and
expansions
1.1 DEFINITIONS AND QUESTIONS
The Standard of Living
Standard of living
The level of consumption of goods and services that
people enjoy, on the average; it is measured by average
income per person.
Goods and services
The objects that people value and produce to satisfy
human wants. Goods are physical objects, and services
are work done for people.
1.1 DEFINITIONS AND QUESTIONS
For most people achieving a high standard of living
means finding a good job.
Unemployment
The state of being available and willing to work but
unable to find suitable work.
1.1 DEFINITIONS AND QUESTIONS
The Cost of Living
Cost of living
The number of dollars it takes to buy the goods and
services that achieve a given standard of living.
Inflation
A situation in which the cost of living is rising and the
value of money is shrinking.
1.1 DEFINITIONS AND QUESTIONS
Economic Fluctuations: Recessions and
Expansions
Business cycle
A periodic but irregular up-and-down movement in
production and jobs.
The worst recession ever was the Great Depression.
Great Depression
A period during the 1930s in which the economy
experienced its worst-ever recession.
1.1 DEFINITIONS AND QUESTIONS
Figure 1.1
shows a
business
cycle.
An expansion
ends at a
peak and a
recession
ends at a
trough.
1.2 ECONOMICS: A SOCIAL SCIENCE
Goal of economists is to discover how the economic
world works. Economists distinguish between:
• Positive statements: What is
• Normative statements: What ought to be
The task of economic science:
To discover and catalog positive statements that are
consistent with what we observe in the world and that
enable us to understand how the economic world
works.
1.2 ECONOMICS: A SOCIAL SCIENCE
The task can be broken into three steps:
• Observing and measuring
• Model building
• Testing
Observing and Measuring
Items such as:
• Quantities of resources
• Wages and work hours
• Prices and quantities of goods and services
• Taxes and government spending
• Volume of international trade
1.2 ECONOMICS: A SOCIAL SCIENCE
Model Building
Economic model
A description of some aspect of the economic world that
includes only those features of the world that are
needed for the purpose at hand.
1.2 ECONOMICS: A SOCIAL SCIENCE
Testing
A model’s predictions might correspond to or conflict
with the data.
Economic theory
A generalization that summarizes what we understand
about the economic choices that people make and the
economic performance of industries and nations.
1.2 ECONOMICS: A SOCIAL SCIENCE
Unscrambling Cause and Effect
The central idea that economists use to unscramble
cause and effect is ceteris paribus.
Ceteris Paribus
Ceteris paribus means “other things being equal.”
But ceteris paribus can be a problem in economics when
testing a model.
1.2 ECONOMICS: A SOCIAL SCIENCE
Economist take three complementary approaches:
• Natural experiments
• Statistical investigations
• Economic experiments
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.
1.2 ECONOMICS: A SOCIAL SCIENCE
Statistical Investigations
Correlation
The tendency for the values of two variables to
move in a predictable and related way.
Post hoc fallacy
The error of reasoning that a first event causes a
second event because the first occurred before
the second.
1.2 ECONOMICS: A SOCIAL SCIENCE
Economic Experiments
Economic experiments put real subjects in a
decision-making situation and vary the influence of
interest to discover how the subjects respond to one
factor at a time. A relatively new approach.
1.3 THE ECONOMIC WAY OF THINKING
Five core ideas:
•
•
•
•
•
Rational choice
Cost
Benefit
Margin
Incentives
1.3 THE ECONOMIC WAY OF THINKING
Rational Choice
Using the available resources to satisfy most effectively
the wants of the person making the choice.
Cost: What You Must Give Up
Opportunity cost
The highest-valued alternative forgone.
Sunk Cost
A previously incurred and irreversible cost.
1.3 THE ECONOMIC WAY OF THINKING
 Benefit: Gain Measured by What You Are
Willing to Give Up
Benefit
The gain or pleasure that something brings.
On the Margin
Margin
A choice that is made by comparing all the relevant
alternatives systematically and incrementally.
1.3 THE ECONOMIC WAY OF THINKING
Marginal Cost
The cost of a one-unit increase in an activity
Marginal Benefit
What you gain when you get one more unit of something.
Making a Rational Choice
When we take those actions for which marginal benefit
exceeds or equals marginal cost.
1.3 THE ECONOMIC WAY OF THINKING
Responding to Incentives
In making our choices, we respond to incentives.
If the cost of something rises, we try to find a less costly
alternative.
If the benefit of something rises, we do more of that thing.
Example: most students believe that studying just before
an exam has a bigger benefit that studying a long time
before the exam. So study time increases as the exam
gets closer.
1.4 WHY ECONOMICS IS WORTH STUDYING
Two main benefits from studying economics are:
• Understanding
• Expanded career opportunities
Understanding
Economic ideas are all around you. You cannot ignore
them.
As you progress with you study of economics, you’ll gain a
deeper understanding of what is going on around you.
1.4 WHY ECONOMICS IS WORTH STUDYING
Expanded Career Opportunities
Most students of economics don’t become economists.
But knowledge of economics is vital in many fields such
as banking, finance, business, management, insurance,
real estate, law, government, journalism, health care and
the arts.
Economics graduates are not the highest-paid
professional, but they are close to the top.
1.4 WHY ECONOMICS IS WORTH STUDYING
Figure 1.1 shows some
earnings comparisons.
Graduates in disciplines
that teach problem
identifying, problem
solving, and strategic
brokering are top of the
earnings distribution:
• engineering
• computer science
• economics
1.4 WHY ECONOMICS IS WORTH STUDYING
4.1
The Costs of Studying Economics
The main cost of studying economics is forgone leisure
time.
Most students find that economics is difficult and that it
takes time to master.
The trick is practice, or learning by doing.
Benefits Versus Costs
Weigh up your benefits and costs!
APPENDIX CHECKLIST
When you have completed your study of this
appendix, you will be able to
1
Interpret a scatter diagram, a time-series graph, and
a cross-section graph.
2
Interpret the graphs used in economic models.
3
Define and calculate slope.
4
Graph relationships among more than two
variables.
APPENDIX: MAKING AND USING GRAPHS
Basic Idea
A graph enables us to visualize the relationship
between two variables.
To make a graph, set two lines perpendicular to each
other:
• The horizontal line is called the x-axis.
• The vertical line is called the y-axis.
• The common zero point is called the origin.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.1 How
to make a graph
The horizontal axis
(x-axis) measures
temperature.
The vertical axis (yaxis) measures ice
cream consumption.
APPENDIX: MAKING AND USING GRAPHS
Point A shows that when
the temperature is 40
degrees, ice cream
consumption is only 5
gallons a day.
Point B shows that when
the temperature is 80
degrees, ice cream
consumption jumps to 20
gallons a day.
APPENDIX: MAKING AND USING GRAPHS
Interpreting Data Graphs
Scatter diagram
A graph of the value of one variable against the value of
another variable.
Time-series graph
A graph that measures time on the x-axis and the
variable or variables in which we are interested on the
y-axis.
APPENDIX: MAKING AND USING GRAPHS
Trend
A general tendency for the value of a variable to rise or
fall.
Cross-section graph
A graph that shows the values of an economic variable
for different groups in a population at a point in time.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.2(a) shows a
scatter diagram.
In 1996 (marked 96),
income per person was
$21,100 and
expenditure per person
was $20,100.
The data for the 1990s
show that as income
increases, expenditure
also increases.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.2(b) shows
another scatter diagram.
In 1993 (marked 93) when
the price of an international
phone call was $1.24 a
minute, 11.4 billion minutes
of calls were made.
The data show that as the
price falls, the number of
calls increases.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.2(c) shows a
times-series graph.
The graph shows when
the price of coffee was:
• High and low.
• Rising and falling.
• Changing quickly
and slowly.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.2(d) shows a
cross-section graph.
The graph shows the
percentage of people
who participate in
various sports
activities.
APPENDIX: MAKING AND USING GRAPHS
Interpreting Graphs Used in Economic
Positive relationship or direct relationship
A relationship between two variables that move in the
same direction.
Linear relationship
A relationship that graphs as a straight line.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.3(a) shows a
positive (direct) relationship.
At a speed of 40 MPH, you
travel 200 miles in 5 hours—
point A.
At a speed of 60 MPH, you
travel 300 miles in 5 hours—
point B.
As the speed increases, the
distance traveled in 5 hours
increases proportionately.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.3(b) shows a
positive (direct) relationship.
As the distance sprinted
increases, recovery time
increases.
But sprint twice as far and
it takes more than twice as
long to recover—the curve
gets steeper.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.3(c) shows a
positive (direct)
relationship.
As study time increases,
the number of problems
worked increases.
But study twice as long
and the number of
problems you work less
than double—the curve
gets less steep.
APPENDIX: MAKING AND USING GRAPHS
Negative relationship or inverse relationship
A relationship between two variables that move in
opposite directions.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.4(a) shows a
negative (inverse)
relationship.
As the time playing tennis
increases, the time playing
squash decreases.
Because one more hour of
tennis means one hour less
of squash, the relationship
between these two
variables is described by a
straight line.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.4(b) shows a
negative (inverse) relationship.
As the journey length
increases, the cost per mile of
the trip falls.
But there is a limit to how
much the cost per mile can
fall, so the curve becomes
less steep as journey length
increases.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.4(c) shows a
negative (inverse) relationship.
As leisure time increases,
the number of problems
worked decreases.
But the tenth hour of leisure
(the first hour of work)
decreases the number of
problems worked most, so
the curve becomes steeper
as leisure time increases.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.5(a) shows
a maximum point.
As the rainfall increases:
1. The curve slopes upward as
the yield per acre rises.
2. The curve is flat at point
A, the maximum yield.
3. Then slopes downward as
the yield per acre falls.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.5(a) shows a
minimum point.
As the speed increases:
1. The curve slopes
downward as the cost per
mile falls.
2. The curve is flat at point
B, the minimum cost per
mile.
3. The curve slopes upward
as the cost per mile rises.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.6(a) shows
variables that are unrelated.
As the price of bananas
increases, the student’s
grade in economics
remains at 75 percent.
The curve is horizontal.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.6(b) shows
variables that are unrelated.
As rainfall in California
increases, the output of
French vineyards remains
at 3 billion gallons.
The curve is vertical.
APPENDIX: MAKING AND USING GRAPHS
The Slope of a Relationship
Slope
The change in the value of the variable measured on
the y-axis divided by the change the value of the
variable measured on the x-axis.
Slope = y ÷ x.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.7(a) shows
a positive slope.
1. When ∆x is 4,
2. ∆y is 3.
3. Slope (∆y/∆x) is 3/4.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.7(b) shows
a negative slope.
1. When ∆x is 4,
2. ∆y is –3.
3. Slope (∆y/∆x) is –3/4.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.7(c) shows the
slope of a curve at a point.
Slope of the curve at A
equals the slope of the red
line tangent to the curve at A.
1. When ∆x is 4,
2. ∆y is 3.
3. Slope (∆y/∆x) is 3/4.
APPENDIX: MAKING AND USING GRAPHS
Relationships Among More Than Two
Variables
To graph a relationship that involves more than two
variables, we use the ceteris paribus assumption.
Ceteris Paribus
“other things remaining the same.”
Figure A1.8 shows the relationships between ice cream
consumed, the temperature, and the price of ice cream.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.8(a) shows the relationship between price and
consumption, temperature remaining the same.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.8(b) shows the relationship between temperature
and consumption, price remaining the same.
APPENDIX: MAKING AND USING GRAPHS
Figure A1.8(c) shows the relationship between price and
temperature, consumption remaining the same.