Transcript LECTURE #14: MICROECONOMICS CHAPTER 16 (Chapter 17 in

LECTURE #14: MICROECONOMICS
CHAPTER 16
(Chapter 17 in 4th Edition)
Monopolistic Competition
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Between Monopoly and Oligopoly
C.
Oligopoly: a market structure in which only a few
sellers offer similar or identical products
1.
2.
3.
D.
Economists measure domination using the concentration
ratio.
CR = % of total market output supplied by four largest
firms.
U.S. economy: most four-firm concentration ratios under
50%.
Monopolistic Competition: a market structure in
which many firms sell products that are similar but
not identical
1.
Characteristics of Monopolistic Competition
a.
b.
c.
Many Sellers
Product Differentiation
Free Entry
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4 Types of Market Structure
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Competition with Differentiated Products
A. The Monopolistically Competitive Firm
(MCF) in the Short Run
1. Each firm faces a downward-sloping demand
curve
2. Monopolistically competitive firm follows a
monopolist's rule for maximizing profit
a. MCF chooses the output level MR = MC.
b. MCF sets price using demand curve to ensure
consumers buy amount produced.
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Competition with Differentiated Products
If P > ATC, the firm is earning a profit.
If P < ATC, the firm is earning a loss.
If P = ATC, the firm is earning zero economic profit.
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Competition with Differentiated Products
B.
The Long-Run Equilibrium
1.
When firms in monopolistic competition are making profit,
new firms have an incentive to enter the market.
a.
b.
c.
2.
This increases the number of products from which consumers
can choose.
Thus, the demand curve faced by each firm shifts to the left.
As the demand falls, these firms experience declining profit.
When firms in monopolistic competition are incurring
losses, firms in the market will have an incentive to exit.
a.
b.
c.
Consumers will have fewer products from which to choose.
Thus, the demand curve for each firm shifts to the right.
The losses of the remaining firms will fall.
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Competition with Differentiated Products
1.
Exit and entry process continues until all firms in the market are
earning zero [economic] profit.
a.
b.
2.
Demand and ATC curves are tangent to each other.
At tangency point, P = ATC and firm is earning zero economic profit.
Two characteristics of long-run equilibrium in a monopolistically
competitive market
a.
b.
Price > MC
Price = ATC (due to the freedom of entry and exit).
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Competition with Differentiated Products
C. Monopolistic versus Perfect Competition
1. Excess Capacity
a. Quantity of output produced is smaller than the quantity
that minimizes average total cost (the efficient scale).
b. This implies that firms in monopolistic competition have
excess capacity: Increase output and lower ATC of
production.
c. Firms in perfect competition produce where P = ATCMIN,
2. Markup over Marginal Cost
a. In monopolistic competition, P > MC because firm has
some market power.
b. In perfect competition, P = MC.
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Competition with Differentiated Products
Panel A
Panel B
Panel (a) shows the long-run equilibrium in a monopolistically competitive market,
and panel (b) shows the long-run equilibrium in a perfectly competitive market. Two
differences are notable. (1) The perfectly competitive firm produces at the efficient
scale, where average total cost is minimized. By contrast, the monopolistically
competitive firm produces at less than the efficient scale. (2) Price equals marginal
cost under perfect competition, but price is above marginal cost under monopolistic
competition.
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Competition with Differentiated Products
D.
Monopolistic Competition and the Welfare of Society
1.
2.
3.
One source of inefficiency is the markup over marginal cost.
This implies a deadweight loss.
Because there are so many firms in this type of market
structure, regulating these firms would be difficult.
Also, forcing these firms to set P = MC would force them
out of business.
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Competition with Differentiated Products
4. There are also externalities associated with entry.
a. The product-variety externality occurs because as new
firms enter, consumers get some consumer surplus from
the introduction of a new product. (+)
b. The business-stealing externality occurs because as new
firms enter, other firms lose customers and profit. (-)
c. Depending on which externality is larger, a
monopolistically competitive market could have too few
or too many products.
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Advertising
A. The Debate over Advertising
1. The Critique of Advertising
a. Firms advertise to manipulate people's tastes.
b. Advertising impedes competition because it increases
the perception of product differentiation and fosters
brand loyalty.
c. This suggests that consumers will be less concerned with
price differences among similar goods.
2. The Defense of Advertising
a. Firms use advertising to provide information to
consumers.
b. Advertising fosters competition because it allows
consumers to be better informed about all of the firms in
the market.
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Advertising
B. Advertising as a Signal of Quality
1. The willingness of a firm to spend a large amount
of money on advertising may be a signal to
consumers about the quality of the product being
offered.
2. Note that the content of the advertisement is
unimportant; what is important is that consumers
know that the advertisements are expensive.
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Advertising
C.
Brand Names
1.
In many markets there are two types of firms;
a.
b.
2.
3.
some firms sell products with widely recognized brand names
while others sell generic substitutes.
Critics of brand names argue that they cause consumers to
perceive differences that do not really exist.
Economists defend brand names as a useful way to ensure
that goods are of high quality.
a.
b.
Brand names provide consumers with information about
quality when quality cannot be judged easily in advance of
purchase.
Brand names give firms an incentive to maintain high quality,
because firms have a financial stake in maintaining the
reputation of their brand names.
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Homework
A. Questions for Review: 1, 4, 5, 7
B. Problems and Applications: 1, 3, 9, 10
Note: These are the exact same questions in
Chapter 17 of the 4th edition.
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