Introduc)on to Industrial Organiza)on
(ECON 367)
Izabela Jelovac ijelovac@udel.edu
hBps://www.gate.cnrs.fr/spip.php?ar)cle21
INTRODUCTION TO INDUSTRIAL ORGANIZATION
Faculty
Izabela JELOVAC
GATE LSE (CNRS and University of Lyon), France hBp://www.gate.cnrs.fr/spip.php?ar)cle21 Content
This course presents the bases of the study of markets. It departs from the basic compe))ve market model. Concretely, it analyzes why and how firms tend to avoid the compe))ve model. Different strategies to do so are presented and analyzed. Some very basic no)ons of Game Theory are provided in the Introduc)on. The technical level is kept low.
References
Cabral, 2000. Introduc)on to Industrial Organiza)on. The MIT Press. (main reference) Tirole, 1988. The Theory of Industrial Organiza)on. The MIT Press.
Grading
Final examina)on with open ques)ons and exercices.
Others
Class material is sent by email aber each class. Students are given problem sets to train the concepts and ideas of the course. Office hours are set by appointment.
INTRODUCTION TO INDUSTRIAL ORGANIZATION
Program
PART 1. INTRODUCTION PART 2. OLIGOPOLY
1. Oligopoly Compe))on 2. Collusion
PART 3. PRICE AND NONPRICE STRATEGIES 1. Price Discrimina)on
2. Ver)cal Rela)ons
3. Product Differen)a)on 4. Adver)sing
PART 4. MARKET STRUCTURE 1. Entry Deterrence
2. Mergers and Acquisi)ons
PART 5. RESEARCH AND DEVELOPMENT
Part I
Introduc)on
1.1 Industrial Organiza)on
• Economics of market func)oning
• Economics of firms and markets
• Economics of imperfect markets
Market?
• How to define a market?
• The market is a set of decentralized exchange decisions.
• Goods are subs)tutes.
• To know whether two goods belong to the same market or not, compute their elas)city of subs)tu)on.
• May be difficult.
Market?
• Example: The pharmaceu)cal sector.
Are drugs with the same ac)ve ingredient subs)tutes?
Are drugs with the same therapeu)c proper)es
subs)tutes?
Imperfect?
• What is the problem?
• See microeconomic theory (welfare theorems):
Under some condi)ons, the market is Pareto-‐
efficient. A social planner could not do any beTer.
Imperfect?
• One such condi)on:
– High number of economic agents
! Perfect compe))on, no market power.
• Other condi)ons:
– Symmetric informa)on
– Private goods (excludable, rivalrous)
– No externali)es
Imperfect?
• Example:
– In the pharmaceu)cal sector, prices >> marginal
costs. Is that a sign of market power? Is there any
good reason for such margins? Role of R&D? Role
of marke)ng ac)vi)es? Incen)ves for R&D? Public
interven)on?
4 ques)ons
• Is there market power?
• What are the implica)ons of market power?
• How do firms acquire and maintain market power?
• Is there a role for public policy regarding market
power?
1.2 Microeconomics – a reminder
• To answer the ques)ons:
– What is the problem?
– What are the implica)ons of market power?
• 2 extreme cases:
– Perfect compe))on
– Monopoly
Nota)on
• n stands for the number of firms in a market
• p or P stand for price
• q or Q stand for quan)ty (q for individual qty and Q for market qty)
• Generally,
• Demand: Q(P) or D(P) or inverse demand P(Q)
• Costs func)on: c(Q)
• For simplicity, we oben use here linear demand and costs func)on:
€
Q = q
ii=1 n
∑
€
P(Q ) = a − bQ
€
c(q) = cq
Perfect compe))on
• Many sellers, sufficiently small so as to be price takers
• Homogeneous good
• Price = Marginal Cost
€
Max q
iPq i − cq i ⇒ q i such that P = c
Perfect compe))on
P
Q
Demand
Perfect compe))on
P
Q
CQ
c (Marginal Cost)
E
CPerfect compe))on
P
Q
CQ
c (Marginal Cost)
P
CE
CPerfect compe))on
• Producer surplus = 0
P
Q
CQ
c Consumer surplus
P
CE
CMonopoly
• One single firm decides its price, considering the demand rela)onship, Q = D(P).
• Price is such that Marginal Cost = Marginal
Revenue
Monopoly
Formally:
€
Max Q Q.P ( Q ) − c. Q FOC :
P (Q) + Q. P ( ʹ′ Q ) − c = 0
≡ MR = MC
Monopoly
Formally:
€
Max Q Q.P ( Q ) − c. Q FOC :
P (Q) + Q. P ( ʹ′ Q ) − c = 0
≡ MR = MC
€
Max P P.D (P ) − c.D(P )
FOC :
D( P ) + ( P − c). D (P ʹ′ ) = 0
≡ P − c
P = 1 ε
Inverse elas)city rule
Monopoly
P
Q
CQ
P
CE
Cc
Monopoly
P
Q
CQ
P
CE
Cc
Marginal revenue
Monopoly
P
Q
CQ
P
CE
Cc
Marginal revenue
Monopoly
P
Q
CQ
P
CE
Cc
Monopoly
P
Q
CQ
P
CE
Cc
Q
MMonopoly
P
Q
CQ
P
CE
Cc
Q
MP
ME
MMonopoly
P
Q
CQ
P
CE
Cc
Q
MP
MConsumer Surplus
E
MMonopoly
P
Q
CQ
P
CE
Cc
Q
MP
ME
MProducer Surplus
Monopoly
P
Q
CQ
P
CE
Cc
Q
MP
MDead Weight Loss
E
MMonopoly
P
Q
CQ
P
CE
Cc
Q
MP
MDead Weight Loss
E
MMonopoly
P
Q
CQ
P
CE
Cc
Q
MP
MA E
MB C
To sum up
E
CE
MConsumer surplus A + B + C A
Producer surplus 0 B
Total welfare A + B + C A + B
To sum up
• In a monopoly, B is transferred from consumers to producers
– Producers are beBer off with market power – What strategies to acquire market power?
• Loss of C is not compensated
– Efficiency loss (imagine a lower price) – Dead weight loss
– Worth for any price above marginal cost, even if in a lower
extend
Example
• In the pharmaceu)cal sector
P >> MC = 0
Dead weight loss?
Consumers do not pay P
Demand is not D(P)
Other implica)ons of market power
• Poten)ally, a redistribu)ve issue because of the transfer of B
• Costly to acquire market power
• Loss of produc)ve efficiency (no pressure on costs)
• Natural monopoly (economies of scale: average
costs are decreasing in quan)ty)
1.3 Market concentra)on and market power
• Measures of market concentra)on and market power
– to measure in a simplified way how far a market is from perfect compe))on or from monopoly
• In a market with symmetric firms
– market power is measured by (p – MC) or by (p – MC)/p – market concentra)on is measured by 1/n
– where n is the number of firms in the market
1.3 Market concentra)on and market power
• If firms are asymmetric (in costs, for example), we need more sophis)cated indexes
• 3 important indexes:
– Lerner index
– Coefficient C M
– Herfindahl index
1.3 Market power and market concentra)on
• Lerner index:
– where s i is firms i’s market share:
– The Lerner index L measures market power
€
L ≡ s
ip − MC
ii=1
p
n
∑
€
s
i= q
iq
ii=1 n
∑
1.3 Market power and market concentra)on
• The coefficient C M :
– It is the sum of the market shares of the m largest firms (firms are ranked according to size)
– It measures market concentra)on – It varies between ...
€
C
m≡ s
ii=1 m
∑
1.3 Market power and market concentra)on
• The Herfindahl index:
– It is the sum of the market shares of the m largest firms
– It measures market concentra)on
– It varies between ... (oben mul)plied by 10,000)
€
H ≡ s
i2i=1 n