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Chapter 10
Monopoly

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Lecture plan
 Objectives
 Introduction
 Features
 Types of Monopoly
 Demand and MR Curve
 Price and Output Decisions in Short Run
 Price and Output Decisions in Long Run
 Supply Curve of Monopolist
 Multiplant Monopolist
 Price Discrimination
 Price and Output Decisions of Discriminating
Monopolist
 Economic Inefficiency of Monopolist

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Objectives
 To examine the nature and different forms of a monopoly
market.
 To explore the vistas of emergence of monopoly power,
with focus on barriers to enter the market.
 To analyze the pricing and output decisions of a
monopolist in the short run and long run.
 To develop an understanding of output and pricing
decisions of a multi plant monopolist.
 To explore the nuances of price discrimination by a
monopolist and the different degrees of such
discrimination.
 To lay down a representation of the economic
inefficiency of monopoly.

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Introduction
 A monopoly (from the Greek word “mono” meaning
single and “polo” meaning to sell) is that form of market
in which a single seller sells a product (good or service)
which has no substitute.
 Monopoly exists when there is no close substitute to the
product and also when there is a single producer and
seller of the product
 E.g. Indian Railway is a monopoly, since there is no other
agency in the country that provides railway service.
 Pure monopoly is that market situation in which there is
absolutely no substitute of the product, and the entire
market is under control of a single firm.

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Features
 Single seller
 The entire market is under control of a single firm.
 Single product
 A monopoly exists when a single seller sells a
product which has no substitute or, at least, no close
substitute in the market.
 No difference between firm and industry
 There is a single firm in the industry
 Independent decision making
 Firm is regarded as a price maker
 Restricted entry
 Existence of barriers leads to the emergence and/or
survival of a monopoly

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Types of Monopoly
 Legal Monopoly
 Created by the laws of a country in the greater public interest.
 To prevent disparity in distribution of wealth, or imbalanced
growth of the economy
 Economic Monopoly
 Created due to superior efficiency of a particular player.
 Attainment of economies of scale leads to monopoly, often referred
to as an “innocent” or a structural barrier.
 Technical know-how restrained in the hold of single firm
 Natural Monopoly
 Formed when the size of the market is so small that it can
accommodate only one player.
 Regional Monopoly
 Geographical or territorial aspects also help in creation of
monopolies.

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 The demand curve of the
monopolist is highly price
inelastic because there is no
close substitute and
consumers have no or very
little choice.
 It is not perfectly inelastic
because pure monopoly does
not exist in real life.
 Hence it faces a normal
downward sloping demand (AR)
curve.
 MR curve corresponds.
Demand and MR Curves
MR
AR
Revenue,
Cost
Quantity
O

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Price and Output Decisions in Short Run
 The monopolist cannot set
both price and quantity at its
own will.
 In order to maximize profit a
monopoly firm follows the rule
of MR=MC when MC is rising.
 A monopoly firm may earn
supernormal profit or normal
profit or even subnormal profit
in the short run.
 The negative slope of the
demand curve is instrumental
for chances of monopoly
profits in the short run.
 In the short run, the firm would
reap the benefits of supplying
a product which not only is
unique, but also has negligible
cross elasticity.
BPE
QE
Firm maximizes profit where
(i) MR=MC (ii) MC cuts MR from
below, at point E.
Equilibrium price=OPE, Output= OQE
Total revenue =OPEBQE
Total cost = OAEQE
Supernormal profit= AEBPE,
since price (AR) > AC
E AR
MR
Quantity
Price,
Revenue,
Cost
O
MC
AC
A
AR>AC

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Price and Output Decisions in Short Run
Total revenue= OPEBQE
Total cost = OPEBQE
Profit = Nil
Firm makes normal profit.
B
E
PE
QE
AR
AC
MR
MC
QuantityO
Price,
Revenue,
Cost
MR
AR
MC AC
E
Quantity
Price,
Revenue,
Cost
O
Total revenue= OPECQE
Total cost = OABQE
Loss = ABCPE
Firm makes loss.
B
QE
A
CPE
AR=AC AR<AC

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 A monopolist is in full control of the market price
 It would not continue to incur loss in the long run.
 It would try to reduce cost of production
 Otherwise it would close down in the long run.
 Monopolist would try to earn at least normal profit in the long run and
may earn supernormal profit due to entry restrictions in the market.
 If in the long run a monopoly firm earns supernormal profit
 This would attract competition and high price would make it possible for a
new entrant to survive.
 To retain its monopoly power, the firm may have to resort to a low
price and earn only normal profit even in the long run to create an
economic barrier to new entrants.
Price and Output Decisions in Long Run

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Supply Curve of Monopoly Firm
 A monopolist is a price maker
 The firm itself sets the price of the product it sells,
instead of taking the price as given.
 It equates MC with MR for profit maximization,
but unlike perfect competition, it does not
equate its price to MR.
 Supply of the good by the monopolist at a given
price would be determined by both the market
demand and the MC curve.
 As such, there is no defined supply curve for a
monopolist.

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Multi Plant Monopoly
 A monopolist may produce a homogeneous product in different
plants.
 different cost functions but the same demand function for the entire
market.
 hence the same AR and MR curves for the entire market.
 A multi plant monopolist has to take two decisions:
 how much to produce and what price to sell at, so as to maximize its profit
 how to allocate the profit maximizing output between the plants.
 Assuming that a monopoly firm produces in two plants, A and B.
 Profit maximising output will be at MR= MCA= MCB
 If MCA< MCB, it would increase production in A, (lower MC) and reduce
production in B (higher MC), till the equality is satisfied.
 The firm produces till MCA and MCB are individually equal to MR, which
is same for both plants.

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Multi Plant Monopoly
• Monopoly firm may produce a homogeneous
product in different plants
– firm has different cost functions from multiple plants,
(MC = MCA+MCB)
– faces the same demand function for the entire
market.
• Firm has to decide
– The profit maximizing output and price; (MC=MR)
– Allocation of the profit maximizing output between the
plants (MR = MCA+MCB)
• Firm will produce more in the plant with lower
cost than in the one with higher cost

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Multi Plant Monopoly
P=A
R
E2
QB
B2
AC
MC
E
MR
AR
Price,
Revenue,
Cost
Quantity
O
Panel a
MCB
ACB
Panel c
QA
B1
E1
Panel b
MCA ACA
• Panel a shows equilibrium of the monopoly firm, where OQ is the profit
maximizing output (MR=MC) and OP is the price (AR).
• Panel b shows plant A
• Panel c shows plant B
• PP=AR is the price line for each of the plants.
• Since MCA< MCB;
• firm will produce more in A and less in B (OQA>OQB)
B
Q
P
MR=MCA = MCB
O O

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Price Discrimination
 Discrimination among buyers on the basis of the price charged for
the same good (or service).
 Objective is to maximise sales
Preconditions of Price Discrimination
 Market control
 Market imperfection and control are necessary
 Monopoly is the most suitable market condition, because it is a
price maker.
 Division of market
 when the whole market can be divided into various segments,
and transfer of goods between the markets is not possible
 Different price elasticities of demand in different markets
 Separation of market is a necessary condition for price
discrimination, but the sufficient condition is that price elasticities
of demand should be different in these market segments

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Bases of Price Discrimination
 Personal
 On basis of the paying capacity and/or the intensity of needs.
 Since this discrimination is being done on a personal basis, the
good (or service) is non transferable.
 Geographical
 People living in different areas are required to pay different
prices for the same product.
 E.g. edible oils and many packaged food items are sold at different
prices in different States of India.
 Time
 The same person may be required to pay different prices for the
same product.
 E.g. off season discounts.
 Purpose of use
 Customers are segregated on basis of their purpose of use.
 E.g. electricity rates are lower for domestic purpose and higher for
industrial purpose.

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Degrees of Price Discrimination
Pigou has identified three degrees of price discrimination.
 First Degree
 charges a price exactly equal to the marginal utility of the consumer
and leaves no consumer surplus.
 Joan Robinson referred to it as perfect discrimination.
 Second Degree
 Divides consumers in groups on the basis of their paying
capacities; a person with lower paying capacity is charged a lower
price and vice versa
 Takes away the major (but not entire) portion of consumer surplus.
 Third Degree
 Segregates consumers such that each group of consumers is a
separate market, and charges the price on basis of price elasticity
of different groups.
 Takes away only a small portion of consumer surplus.

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Degrees of Price Discrimination
First Degree: Monopolist’s income is equal to the area OPEQ leaving no
consumer surplus. MR curve coincides with AR.
Second Degree: divided consumers in three segments and charges price P1,
P2, P3 and leaves some surplus except the third group which marginal
consumer.
Third Degree: charges higher price to buyers with less elastic demand and
lower price to those with highly elastic demand, and maximizes its revenue.
First degree Second degree Third degree
D
O
Q
E
D=MR
P
O
Quantity
Price
Q2
P2
E2
A1
A1
EP
Q
D
O
P1
Q1
E1
Q1
P1
E1
E3P3
Q3
A2

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Price and Output Decisions of
Discriminating Monopolist
 Assume that the firm can segregate the market on basis of price elasticity of
demand: M1 with high price elasticity and M2 with low price elasticity.
 The rule is:
 Lower price and more supply in the market with high price elasticity
 Higher price and less supply in the market with low price elasticity.
 The firm will charge lower price in the market M1 and higher price in the market
M2 and it would supply more to the market M1 and less to the market M2.
 Firm would determine the profit maximizing output at MC=MR while MC is
increasing.
 The upper portion of the AR curve refers to the less elastic demand and the
lower portion to highly elastic demand.
 The MR curve corresponds to the AR curve.

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Price and Output Decisions of
Discriminating Monopolist
 In the market M1 the optimum output is OQ1 and price is OP1
 In the market M2 the optimum output is OQ2 and price is OP2
 OQ1> OQ2 and OP1< OP2
 Price discrimination leads to greater profits.
 OPEQ is less than the area given by total area of OP1E1Q1+OP2E2Q2.
MC=MR1=MR2
Market 1 Market 2Firm
MR1
AR1
O
P1
E1
Q1
MC
ARMR
Price,
Revenue,
Cost
O Quantity
P
Q
E
AR2MR2
O
E2
P2
Q2

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Economic Inefficiency of Monopoly
 A monopoly firm operates at less than optimum output and charges
a higher price.
 Monopoly does not allow optimum use of all the factors of
production, thereby allowing loss of output and creating excess
capacity in the economy
 Considered as a loss of social welfare, hence authorities make
regulations to check and prevent monopoly practices.
 Also termed as deadweight loss to the economy, since this increase
in output is actually possible under perfect competition.
 Compare two firms, one under perfect competition, and the other
under monopoly to explain the condition; assuming that both the
firms earn normal profits.
 The firm under perfect competition faces a horizontal demand curve
(DC), whereas the monopoly firm faces a downward sloping curve DM,
which is less elastic.

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Economic Inefficiency of Monopoly
 The monopolist produces an output QM(<QC), and sells at price PM(>PC) (Fig 1)
 OQC-OQM (i.e. QMQC), is regarded as excess capacity.
 Perfectly competitive firm allows maximum consumer surplus (PCDB) (Fig 2).
 Monopoly takes away PCPMAE from consumers to the firm.
 AEB is neither part of firm’s income nor of consumer surplus; hence is the deadweight
loss or economic inefficiency due to monopoly.
EC
QCQM
EM
PM
Fig 1: Excess Capacity Fig 2: Deadweight Loss
QC
B MC=AC=MRP=
ARP
PC
E
A
QM
PM
MRM
D
ARM
O
Quantity
PC
DC
DM
LAC
Quantity
O
Price,
Revenue,
Cost

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Summary
 A monopoly is that form of market in which a single seller sells a product
(or service) which has no substitute.
 Pure monopoly is where there is absolutely no substitute of the product,
and the entire market is under control of a single firm.
 A monopoly has a single seller, sells a single product (pure monopoly) and
decides on its own price and output, based on individual demand and cost
conditions and is hence regarded as a price maker.
 In monopoly the firm and the industry are one and the same.
 Barriers to entry are the major sources (or reasons) of monopoly power
and may include restriction by law, control over key raw materials,
specialized know how restricted through patents or licences, small market
and economies of scale.
 A monopoly firm has a normal demand curve with a negative slope. The
demand curve is highly price inelastic because there is no close substitute.
 A monopolist firm may earn supernormal profit, or normal profit, or may
even incur loss in the short run, but would not incur loss in the long run.

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Summary
 The monopolist being a price maker does not have any supply curve.
 A multi plant monopolist decides on how much to produce and what price to
sell at so as to maximize its profit on the basis of the principle of
marginalism.
 When a seller discriminates among buyers on basis of the price charged for
the same good (or service), such a practice is called price discrimination.
 Price discrimination can be done on personal basis (demographical, paying
capacity or need), on the basis of geography, on the basis of time or
purpose of use.
 The discriminating firm will charge a higher price and supply less to the
market having higher price elasticity and a lower price and supply more in
the market having lower price elasticity.
 Monopoly runs at less than optimum level of output and generates excess
capacity in the economic system, which in turn results in deadweight loss
that adds neither to consumer surplus, nor to seller’s profit.