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© 2007 Worth Publishers Essentials of Economics Krugman • Wells • Olney
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© 2007 Worth Publishers Essentials of Economics Krugman • Wells • Olney
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How much am I willing to pay for that
used textbook?
What you will learn in
this chapter:
➤ The meaning of consumer
surplus and its relationship to the
demand curve
➤ The meaning of producer surplus
and its relationship to the supply
curve
➤ The meaning and importance of
total surplus and how it can be
used both to measure the gains
from trade and to evaluate the
efficiency of a market
➤ How to use changes in total surplus
to measure the deadweight loss of
taxes
➤ Why the deadweight loss of a tax
means that its true cost is more
than the amount of tax revenue
collected
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Consumer Surplus and the Demand Curve
Willingness to Pay and the Demand Curve
A consumer’s willingness to pay for a good
is the maximum price at which he or she
would buy that good.
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Consumer Surplus and the Demand Curve
Willingness to Pay and the Demand Curve
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Consumer Surplus and the Demand Curve
Willingness to Pay and Consumer Surplus
TABLE 6-1
Consumer Surplus When the Price of a Used Textbook Is $30
Potential
buyer
Price paid
Individual consumer surplus
= willingness to pay − price paid
$59
$30
$30
Brad
45
30
15
Claudia
35
30
5
Darren
25
−
−
Edwina
10
−
−
Aleisha
Willingness to pay
Total consumer surplus: $49
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Consumer Surplus and the Demand Curve
Willingness to Pay and Consumer Surplus
Individual consumer surplus is the net gain
to an individual buyer from the purchase of a
good. It is equal to the difference between the
buyer’s willingness to pay and the price paid.
Total consumer surplus is the sum of the
individual consumer surpluses of all the
buyers of a good.
The term consumer surplus is often used to
refer to both individual and to total consumer
surplus.
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Consumer Surplus and the Demand Curve
Willingness to Pay and Consumer Surplus
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Consumer Surplus and the Demand Curve
Willingness to Pay and Consumer Surplus
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Consumer Surplus and the Demand Curve
How Changing Prices Affect Consumer Surplus
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Consumer Surplus and the Demand Curve
How Changing Prices Affect Consumer Surplus
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Producer Surplus and the Supply Curve
Cost and Producer Surplus
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Producer Surplus and the Supply Curve
Cost and Producer Surplus
A potential seller’s cost is the lowest price at
which he or she is willing to sell a good.
Individual producer surplus is the net gain
to a seller from selling a good. It is equal to
the difference between the price received and
the seller’s cost.
Total producer surplus in a market is the
sum of the individual producer surpluses of all
the sellers of a good.
Economists use the term producer surplus
to refer both to individual and to total producer
surplus.
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Producer Surplus and the Supply Curve
Cost and Producer Surplus
TABLE 6-2
Producer Surplus When the Price of a Used Textbook Is $30
Potential
seller
Cost
Price received
Individual producer surplus
= price received − cost
Andrew
$5
$30
$25
Betty
15
30
15
Carlos
25
30
5
Donna
35
−
−
Engelbert
45
−
−
Total consumer surplus: $45
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Producer Surplus and the Supply Curve
Cost and Producer Surplus
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Producer Surplus and the Supply Curve
Cost and Producer Surplus
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Producer Surplus and the Supply Curve
Changes in Producer Surplus
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Consumer Surplus, Producer Surplus, and the
Gains from Trade
The Gains from Trade
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Consumer Surplus, Producer Surplus, and the
Gains from Trade
The Gains from Trade
The total surplus generated in a market
is the total net gain to consumers and
producers from trading in the market. It is
the sum of the producer and the
consumer surplus.
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Consumer Surplus, Producer Surplus, and the
Gains from Trade
The Efficiency of Markets: A Preliminary View
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Consumer Surplus, Producer Surplus, and the
Gains from Trade
The Efficiency of Markets: A Preliminary View
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Consumer Surplus, Producer Surplus, and the
Gains from Trade
The Efficiency of Markets: A Preliminary View
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Consumer Surplus, Producer Surplus, and the
Gains from Trade
The Efficiency of Markets: A Preliminary View
The market equilibrium maximizes total surplus—the
sum of producer and consumer surplus. It does this
because the market performs four important
functions:
1. It allocates consumption of the good to the
potential buyers who value it the most, as
indicated by the fact that they have the highest
willingness to pay.
2. It allocates sales to the potential sellers who most
value the right to sell the good, as indicated by the
fact that they have the lowest cost.
3. It ensures that every consumer who makes a
purchase values the good more than every seller
who makes a sale, so that all transactions are
mutually beneficial.
4. It ensures that every potential buyer who doesn’t
make a purchase values the good less than every
potential seller who doesn’t make a sale, so that
no mutually beneficial transactions are missed.
Maximizing total surplus at
your local hardware store.
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Applying Consumer and Producer Surplus:
The Efficiency Costs of a Tax
The excess burden, or deadweight loss,
from a tax is the extra cost in the form of
inefficiency that results because the tax
discourages mutually beneficial
transactions.
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Applying Consumer and Producer Surplus:
The Efficiency Costs of a Tax
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Applying Consumer and Producer Surplus:
The Efficiency Costs of a Tax
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Applying Consumer and Producer Surplus:
The Efficiency Costs of a Tax
Deadweight Loss and Elasticities
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Applying Consumer and Producer Surplus:
The Efficiency Costs of a Tax
Deadweight Loss and Elasticities
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KEY TERMS
Willingness to pay
Individual producer surplus
Individual consumer surplus
Total producer surplus
Total consumer surplus
Producer surplus
Consumer surplus
Total surplus
Cost
Excess burden
Deadweight loss
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