1. What Is This Class About?
People make choices as they try to attain their goals. Choices are necessary because we live in a world of scarcity.
Scarcity: A situation in which unlimited wants exceed the limited resources available to fulfill those wants
Economics is the study of these choices.
Economists study these choices using economic models, simplified versions of reality used to analyze real-world economic situations.

2. Typical “Economics” Questions
We will learn how to answer questions like these:
• How are the prices of goods and services determined?
• How does pollution affect the economy, and how should government policy deal with these effects?
• Why do firms engage in international trade, and how do government policies affect international trade?
• Why does government control the prices of some goods and services, and what are the effects of those controls?

3. Three Key Economic Ideas
1.1
Explain these three key economic ideas:
People are rational;
People respond to economic incentives; and
Optimal decisions are made at the margin.

4. 1. People Are Rational
Economists generally assume that people are rational.
Rational: Using all available information to achieve your goals.
Rational consumers and firms weigh the benefits and costs of each action and try to make the best decision possible.
Example: Microsoft doesn’t randomly choose the price of its Windows software; it chooses the price(s) that it thinks will be most profitable.

5. 2. People Respond to Economic Incentives
As incentives change, so do the actions that people will take.
Example: Changes in several factors have resulted in increased obesity in Americans over the last couple of decades, including:
Decreases in the price of fast food relative to healthful food
Improved non-active entertainment options
Increased availability of health care and insurance, protecting people against the consequences of their actions

6. 3. Optimal Decisions Are Made at the Margin
While some decisions are all-or-nothing, most decisions involve doing a little more or a little less of something.
Example: Should you watch an extra hour of TV, or study instead?
Economists think about decisions like this in terms of the marginal cost and benefit (MC and MB): the additional cost or benefit associated with a small amount extra of some action.
Comparing MC and MB is known as marginal analysis.

7. Microeconomics and Macroeconomics
Microeconomics is the study of
how households and firms make choices,
how they interact in markets, and
how the government attempts to influence their choices
Macroeconomics is the study of the economy as a whole, including topics such as inflation, unemployment, and economic growth.

8. 1. What Goods and Services Will Be Produced?
Individuals, firms, and governments must decide on the goods and services that should be produced.
An increase in the production of one good requires the reduction in the production of some other good. This is a trade-off, resulting from the scarcity of productive resources.
The highest-valued alternative given up in order to engage in some activity is known as the opportunity cost.
Example: the opportunity cost of increased funding for space exploration might be giving up the opportunity to fund cancer research.

9. 2. How Will the Goods Be Produced?
A firm might have several different methods for producing its goods and services.
Example: A music producer can make a song sound good by
Hiring a great singer, and using standard production techniques; or
Hiring a mediocre singer, and using Auto-Tune to correct the inaccuracies.
Example: As the cost of manufacturing labor changes, a firm might respond by
Changing its production technique to one that employs more machines and fewer workers; or even
Moving its factory to a location with cheaper labor

10. 3. Who Will Receive the Goods and Services?
The way we are most familiar with in the United States is that people with higher incomes obtain more goods and services.
Changes in tax and welfare policies change the distribution of income; though people often disagree about the extent to which this “redistribution” is desirable.

11. Efficiency of Economies
Market economies tend to be more efficient than centrally-planned economies.
Market economies promote:
Productive efficiency, where goods or services are produced at the lowest possible cost; and
Allocative efficiency, where production is consistent with consumer preferences: the marginal benefit of production is equal to its marginal cost
These efficiencies come about because all transactions result from voluntary exchange: transactions that make both the buyer and seller better off.

12. Economic Models Understand the role of models in economic analysis.
1.3
Understand the role of models in economic analysis.

13. Economic Models
Economists develop economic models to analyze real-world issues.
Building an economic model often follows these steps:
Decide on the assumptions to use in developing the model.
Formulate a testable hypothesis.
Use economic data to test the hypothesis.
Revise the model if it fails to explain the economic data well.
Retain the revised model to help answer similar economic questions in the future.

14. Important Features of Economic Models
Assumptions and simplifications: every model needs them in order to be useful.
Testability: good models generate testable predictions, which can be verified or disproven using data.
Economic variables: something measurable that can have different values, such as the incomes of doctors.

15. The Scientific Nature of Economics
Economists try to mimic natural scientists by using the scientific method. But economics is a social science; studying the behavior of people is often tricky.
When analyzing human behavior, we can perform:
Positive analysis: the study of “what is?”; and/or
Normative analysis: the study of “what ought to be?”
Economists generally perform positive analysis.

16. Terminology in Economics
Like all fields of study, economics uses terms or jargon with specific, precise meanings.
Sometimes these terms will be used in ways that differ even from closely related disciplines.
Examples:
Technology: the processes a firm uses for turning inputs into outputs of goods and services
Capital: manufactured goods that are used to produce other goods and services
Pay close attention to terms defined in class and in the textbook!

17. Common Misconceptions to Avoid
Believing economics is only about money.
Confusing positive and normative analysis.
Assuming familiar meanings for economic terms.

18. Calculating the Slope of a Line
We can calculate the slope of a line as the change in the value of the variable on the y-axis divided by the change in the value of the variable on the x-axis.
Because the slope of a straight line is constant, we can use any two points in the figure to calculate the slope of the line.
Figure 1A.4
Calculating the Slope of a Line
We can calculate the slope of a line as the
change in the value of the variable on the
y-axis divided by the change in the value
of the variable on the x-axis. Because the
slope of a straight line is constant, we can
use any two points in the figure to calculate
the slope of the line. For example, when the
price of pizza decreases from $14 to $12, the
quantity of pizza demanded increases from
55 per week to 65 per week. So, the slope of
this line equals −2 divided by 10, or −0.2.

19. Calculating the Slope of a Line—continued
For example, when the price of pizza decreases from $14 to $12, the quantity of pizza demanded increases from 55 per week to 65 per week.
So, the slope of this line equals – 2 divided by 10, or –0.2.
Figure 1A.4
Calculating the Slope of a Line

20. Showing Three Variables on a Graph
The demand curve for pizza shows the relationship between the price of pizzas and the quantity of pizzas demanded, holding constant other factors that might affect the willingness of consumers to buy pizza.
The demand curve for pizza shows the relationship
between the price of pizzas and
the quantity of pizzas demanded, holding
constant other factors that might affect
the willingness of consumers to buy
pizza. If the price of pizza is $14 (point A),
an increase in the price of hamburgers from
$1.50 to $2.00 increases the quantity of pizzas
demanded from 55 to 60 per week (point
B) and shifts us to Demand curve2. Or, if
we start on Demand curve1 and the price
of pizza is $12 (point C), a decrease in the
price of hamburgers from $1.50 to $1.00
decreases the quantity of pizza demanded
from 65 to 60 per week (point D) and shifts
us to Demand curve3.
Figure 1A.5
Showing Three Variables on a Graph

21. Showing Three Variables on a Graph (part B)
If the price of pizza is $14 (point A), an increase in the price of hamburgers from $1.50 to $2.00 increases the quantity of pizzas demanded from 55 to 60 per week (point B) and shifts us to Demand curve2.
Figure 1A.5
Showing Three Variables on a Graph

22. Showing Three Variables on a Graph (part C)
Or, if we start on Demand curve1 and the price of pizza is $12 (point C), a decrease in the price of hamburgers from $1.50 to $1.00 decreases the quantity of pizza demanded from 65 to 60 per week (point D) and shifts us to Demand curve3.
Figure 1A.5
Showing Three Variables on a Graph

23. Correlation vs. Causation
Figure 1A.7
Determining Cause and Effect
Using graphs to draw conclusions about cause and effect is dangerous.
For example, in panel (a), as the number of fires in fireplaces increases, the number of leaves on trees falls; but the fires don’t cause the leaves to fall.
In panel (b), as the number of lawn mowers being used increases, so does the rate at which grass grows.
Using graphs to draw conclusions about cause and effect can be hazardous. In
panel (a), we see that there are fewer leaves on the trees in a neighborhood when
many homes have fires burning in their fireplaces. We cannot draw the conclusion
that using fireplaces causes the leaves to fall because we have an omitted
variable—the season of the year. In panel (b), we see that more lawn mowers are
used in a neighborhood during times when the grass grows rapidly and fewer lawn
mowers are used when the grass grows slowly. Concluding that using lawn mowers
causes the grass to grow faster would be making the error of reverse causality.

24. Formula for a Percentage Change
One important formula is the percentage change, which is the change in some economic variable, usually from one period to the next, expressed as a percentage.

25. Production Possibilities Frontiers and Opportunity Costs
2.1
Use a production possibilities frontier to analyze opportunity costs and trade-offs.

26. Production Possibilities Frontier
A production possibilities frontier (PPF) is a curve showing the maximum attainable combinations of two products that may be purchases with available resources and current technology.
Question: Is the PPF a positive or normative tool?
Answer: Positive; it shows “what is”, not “what should be”.

27. A Production Possibilities Frontier for Tesla
Tesla can produce sedans and/or SUVs.
If it wants to produce more sedans, it must reduce the number of SUVS.
Points on the PPF are attainable for Tesla.
Points below the curve are inefficient.
Points above the curve are unattainable with current resources.
Tesla faces a trade-off: To build one more
sedan, it must build one fewer SUV. The
production possibilities frontier illustrates
the trade-off Tesla faces. Combinations on
the production possibilities frontier—like
points A, B, C, D, and E—are technically
efficient because the maximum output is
being obtained from the available resources.
Combinations inside the frontier—like
point F—are inefficient because some resources
are not being used. Combinations
outside the frontier—like point G—are
unattainable with current resources.
Figure 2.1
Tesla’s production possibilities frontier

28. Tesla Can Trade Off Sedans for SUVs
To produce 20 more SUVs (e.g. moving from A to B), Tesla must produce 20 fewer sedans.
The 20 fewer sedans is the opportunity cost of producing 20 more SUVs.
Opportunity cost: The highest-valued alternative that must be given up to engage in an activity.
Figure 2.1
Tesla’s production possibilities frontier

29. Increasing Marginal Opportunity Costs
On the previous slide, opportunity costs were constant.
But opportunity costs are often increasing.
Why? Some resources are better suited to one task than another. The first resources to “switch” are the one best suited to switching.
As the economy moves down the production
possibilities frontier, it experiences
increasing marginal opportunity costs because
increasing automobile production by
a given quantity requires larger and larger
decreases in tank production. For example,
to increase automobile production from 0 to
200—moving from point A to point B—the
economy has to give up only 50 tanks. But to
increase automobile production by another
200 vehicles—moving from point B to point
C—the economy has to give up 150 tanks.
Figure 2.2
Increasing marginal opportunity costs
The more resources already devoted to an activity, the smaller the payoff to devoting additional resources to that activity.

30. Economic Growth on the PPF
As more economic resources become available, the economy can move from point A to point B, producing more tanks and more automobiles.
Shifts in the production possibilities frontier represent economic growth.
Figure 2.3a
Economic growth
Panel (a) shows that as more economic resources become available and technological
change occurs, the economy can move from point A to point B, producing more
tanks and more automobiles.
Economic growth: the ability of the economy to increase the production of goods and services.

31. Technological Change in One Industry
This panel shows technological improvement in the automobile industry.
The quantity of tanks that can be produced remains unchanged.
As in the previous slide, many previously unattainable combinations are now attainable.
Figure 2.3b
Economic growth
Panel (b) shows the results of technological change in
the automobile industry that increases the quantity of vehicles workers can produce
per year while leaving unchanged the maximum quantity of tanks they can produce.
Outward shifts in the production possibilities frontier represent economic growth.

32. A PPF for Exam Grades
Suppose you have a limited amount of time to study for two exams, Economics and Accounting.
What would the production possibilities curve for the exam grades look like?
A straight line, like the PPF for sedans and SUVs or
A bowed-outward curve, like the PPF for tanks and automobiles?
Why? The first hour spent studying Economics is much more valuable than the last hour…

33. Comparative Advantage and Trade
2.2
Describe comparative advantage and explain how it serves as the basis for trade.

34. PPFs for Picking Apples and Cherries
You and your neighbor each have a limited time to pick cherries and/or apples.
If you spend your time picking cherries, you can pick 20 pounds of cherries.
If you spend you time picking apples, you can pick 20 pounds of apples.
Figure 2.4a
Production possibilities for you and your neighbor, without trade
The table shows how many pounds of apples and how many pounds of cherries
you and your neighbor can each pick in one week. The graphs use the data from
the table to construct PPFs for you and your neighbor. Panel (a) shows your PPF.
If you devote all your time to picking apples and none to picking cherries, you
can pick 20 pounds. If you devote all your time to picking cherries, you can pick
20 pounds. Panel (b) shows that if your neighbor devotes all her time to picking
apples, she can pick 30 pounds. If she devotes all her time to picking cherries, she
can pick 60 pounds.

35. PPFs for Picking Apples and Cherries—continued
If your neighbor spends all of her time picking cherries, she can pick 60 pounds of cherries.
If your neighbor spends all of her time picking apples, she can pick 30 pounds of apples.
Figure 2.4b
Production possibilities for you and your neighbor, without trade

36. Specialization and Trade
What if you and your neighbor decided to specialize and trade?
Trade: The act of buying and selling.
Could your neighbor benefit from trade? She is better at picking both apples and cherries…
Both of you can benefit from trade, by specializing in what you are relatively good at. Let’s see how…

37. Gains from Specialization and Trade
Figure 2.5
Gains from trade
When you don’t trade with your neighbor, you pick and consume 8 pounds of apples and 12 pounds of cherries per week—point A in panel (a).
When your neighbor doesn’t trade with you, she picks and consumes 9 pounds of apples and 42 pounds of cherries per week—point C in panel (b).
When you don’t trade with your neighbor, you pick and consume 8 pounds of
apples and 12 pounds of cherries per week—point A in panel (a). When your
neighbor doesn’t trade with you, she picks and consumes 9 pounds of apples and
42 pounds of cherries per week—point C in panel (b). If you specialize in picking
apples, you can pick 20 pounds. If your neighbor specializes in picking cherries,
she can pick 60 pounds. If you trade 10 pounds of your apples for 15 pounds of
your neighbor’s cherries, you will be able to consume 10 pounds of apples and
15 pounds of cherries—point B in panel (a). Your neighbor can now consume 10
pounds of apples and 45 pounds of cherries—point D in panel (b). You and your
neighbor are both better off as a result of the trade.

38. Gains from Specialization and Trade—continued
Figure 2.5
Gains from Trade
If you specialize in picking apples, you can pick 20 pounds. If your neighbor specializes in picking cherries, she can pick 60 pounds.
If you trade 10 pounds of your apples for 15 pounds of your neighbor’s cherries, you will be able to consume 10 pounds of apples and 15 pounds of cherries— point B in panel (a).
Your neighbor can now consume 10 pounds of apples and 45 pounds of cherries— point D in panel (b). You and your neighbor are both better off as a result of trade.

39. Summary of the Gains from Trade
You
Your Neighbor
Apples (in pounds)
Cherries (in pounds)
Production and consumption without trade 8 12 9 42
Production with trade 20 60
Consumption with trade 10 15 45
Gains from trade (increased consumption) 2 3 1
Table 2.1
A summary of the gains from trade

40. Explaining the Gains from Specialization and Trade
How could both of you benefit from trade, when your neighbor was so much better than you?
Economists say your neighbor had an absolute advantage in both cherry- and apple-picking, but you had a comparative advantage in picking apples.
Absolute advantage: The ability of an individual, a firm, or a country to produce more of a good or service than competitors, using the same amount of resources.
Comparative advantage: The ability of an individual, a firm, or a country to produce a good or service at a lower opportunity cost than competitors.

41. Comparative Advantage and the Gains from Trade
Opportunity Cost of Picking
1 Pound of Apples
1 Pound of Cherries
You
1 pound of cherries
1 pound of apples
Your Neighbor
2 pounds of cherries
0.5 pound of apples
Table 2.2
Opportunity costs of picking apples and cherries
The basis for trade is comparative advantage, not absolute advantage.
Individuals, firms, and countries are better off if they specialize in producing goods and services for which they have a comparative advantage and obtain the other goods and services they need by trading.

42. Comparative Advantage and Housework
People living together have to divide up household chores.
Basic economic concepts like comparative advantage can provide useful insight in the division of labor.
Suppose Jack is faster than Jill at both cooking and laundry. However:
Jack is MUCH faster at preparing tasty meals, while
Jack is only a little faster at doing laundry
Jack’s comparative advantage is in cooking—to cook a tasty meal, he gives up the opportunity to perform less laundry than Jill—so he should specialize in this, while Jill specializes in laundry.

43. The Market System Explain the basic idea of how a market system works.
2.3
Explain the basic idea of how a market system works.

44. The Two Key Groups in a Modern Economy
Two key groups participate in the modern economy:
Households consist of individuals who provide the factors of production: labor, capital, natural resources, and entrepreneurial ability.
Households receive payments for these factors by selling them to firms in factor markets.
Firms supply goods and services to product markets; households buy these products from the firms.
All types of work
Physical capital used to produce other goods
Land, water, oil, ore, raw materials, etc.
The ability to bring together factors of production

45. The Circular-Flow Diagram
Circular-flow diagram: A model that illustrates how participants in markets are linked.
Households provide factors of production to firms.
Firms provide goods and services to households.
Firms pay money to households for the factors of production.
Households pay money to firms for the goods and services.
Households and firms are linked together in
a circular flow of production, income, and
spending. The blue arrows show the flow of
the factors of production. In factor markets,
households supply labor, entrepreneurial
ability, and other factors of production to
firms. Firms use these factors of production
to make goods and services that they supply
to households in product markets. The red
arrows show the flow of goods and services
from firms to households. The green arrows
show the flow of funds. In factor markets,
households receive wages and other payments
from firms in exchange for supplying
the factors of production. Households use
these wages and other payments to purchase
goods and services from firms in product
markets. Firms sell goods and services to
households in product markets, and they
use the funds to purchase the factors of production
from households in factor markets.
Figure 2.6
The circular-flow diagram

46. The Circular-Flow Diagram—a Simplified Model
Like all economic models, the circular-flow diagram is a simplified version of reality:
No government
No financial system
No foreign buyers and sellers of goods
We will explore these sectors in later chapters.
Figure 2.6
The circular-flow diagram

47. The Gains from Free Markets
A free market is one with few government restrictions on how a good or service can be produced or sold, or on how a factor of production can be employed.
Countries that come closest to the free market benchmark have been more successful than those with centrally planned economies in providing their people with rising living standards.
This concept is not new: Adam Smith argued for free markets in his 1776 treatise, An Inquiry into the Nature and Causes of the Wealth of Nations.

48. The Beauty of the Market Mechanism
It is not immediately obvious that markets will do better than centrally-planned systems for satisfying human desires.
After all, individuals are acting only in their own rational self-interest.
But markets with flexible prices allow the collective actions of households and firms to signal the relative worth of goods and services.
In this way, the “invisible hand” allows individual responses to collectively end up satisfying the wants of consumers.

49. A Story of the Market System in Action
How do you make an iPad?
Although Apple engineers designed the iPad, Apple does not manufacture iPad components, nor does it assemble the final product.
Hundreds of firms are involved; many probably don’t even know their products will be used in an iPad.
But guided by their own self-interest, they all contribute to the final product—without any desire to enrich Apple or provide enjoyment for iPad purchasers.

50. The Role of the Entrepreneur
An entrepreneur is someone who brings together the factors of production—land, labor, and capital—to produce goods and services.
The best entrepreneurs create products that consumers never even knew they wanted.
“If I had asked my customers what they wanted, they would have said a faster horse.”
- Henry Ford
Entrepreneurs make a vital contribution to economic growth, often with considerable personal risk and sacrifice.

51. Selected Products and Their Inventors
Entrepreneurs make a vital contribution to economic growth by
Responding to consumer demand
Introducing new products
Government policies encouraging entrepreneurship are likely to increase economic growth and raise standards of living.
Product
Inventor
Air conditioning
William Haviland Carrier
Airplane
Orville and Wilbur Wright
Automobile, mass produced
Henry Ford
Biomagnetic imaging
Raymond Damadian
Biosynthetic insulin
Herbert Boyer
DNA fingerprinting
Alec Jeffries …
Vacuum tube
Philo Farnsworth
Zipper
Gideon Sundback
Table 2.3
Important products introduced by entrepreneurs

52. The Legal Basis of a Successful Market System
In a free market, government does not restrict how firms produce and sell goods, or how they employ factors of production.
However governments must provide a sound legal environment that will allow the market system to succeed, including:
Protection of private property
When criminals can take your wages or profits, households and firms have little incentive to work hard.
Property rights—the rights individuals or firms have to the exclusive use of their property, including the right to buy or sell it—are essential here.
Enforcement of contracts and property rights
Important for transactions across time to occur.
An independent court system is critical here.