market structure and competition by a.v. vedpuriswar
TRANSCRIPT
![Page 1: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/1.jpg)
Market structure and competition
By
A.V. Vedpuriswar
![Page 2: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/2.jpg)
Competitors and Competition
A given firm may compete in several input and output markets simultaneously.
It is important to analyse each market separately.
Two firms directly compete if a price increase by one causes many of its customers to do business with the other.
When firms are direct competitors, the strategic choices of one directly affect the performance of the other.
Products tend to be close substitutes when three conditions hold:
- Same or similar product performance characteristics.
- Same or similar occasions for use.
- Sold in the same geographic market.
The degree to which products substitute each other is measured by the cross price elasticity of demand.
Cross price elasticity = percentage change in demand for good Y that results from 1% change in the price of X
![Page 3: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/3.jpg)
Market Structure
Market structure refers to the number and distribution of firms in a market.
We can measure this in many ways.
N firm concentration ratio = Combined market share of the N largest firms in the market.
Herfindahl index = Sum of the squared market shares of all the firms in the market
![Page 4: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/4.jpg)
Problem
The following are the approximate market shares:
Coke – 40%, Pepsi – 30%, 7 Up – 10%, Dr Pepper – 10%
All other brands – 10%
Calculate the Herfindahl index
![Page 5: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/5.jpg)
Herfindahl index = (.4)**2 + (.3)**2 + (.10)**2 + (.10)**2 + (.10)**2
=.16 + .09 + .01 + .01 + .01
=0.28
![Page 6: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/6.jpg)
What would happen if Pepsi took over 7 Up?
![Page 7: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/7.jpg)
Herfindahl index =(.4)**2 + (.4)**2 + (.10)**2 + (.10)**2
= 0.34
![Page 8: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/8.jpg)
Perfect competition
- There are many sellers and well informed buyers.
- Profit is maximised when Price = Marginal cost.
Different forms of market structure
![Page 9: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/9.jpg)
Monopoly
- A firm is a monopolist if it faces little or no competition.
- A monopolist faces a downward sloping demand curve.
- A monopolist selects the price such that marginal revenue equals marginal cost.
- A monopolist can set the price without regard to how other firms will respond.
![Page 10: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/10.jpg)
The monopoly solution (Cont…)
E
G Marginal revenue
Demand
Marginal cost
Quantity per period
pri
ce, m
arg
inal
rev
enu
e, m
arg
inal
co
st,
aver
age
tota
l co
st Average total
cost
![Page 11: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/11.jpg)
- There are many sellers
- Each seller sells a differentiated product
- A product is vertically differentiated when it is unambiguously better or worse than competing products
- A product is horizontally differentiated when only some consumers prefer it to competing products.
- Horizontal differentiation results when consumers have idiosyncratic preferences.
Monopolistic competition
![Page 12: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/12.jpg)
- Location can be a source of idiosyncratic preferences
- Tastes can be a source of idiosyncratic preferences
- The degree of horizontal differentiation depends on the magnitude of search costs, i.e., how easy or hard it is for customers to get information about alternatives.
![Page 13: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/13.jpg)
Monopolistic competition (short run)
MR
D
ATC
MC
Economic profit
C
P
Q
![Page 14: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/14.jpg)
A market in which the actions of individual firms materially affect the industry price level is called Oligopoly.
Each firm has to take into account the strategies of other firms even as it frames its strategy.
Game theory is useful here.
Oligopoly
![Page 15: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/15.jpg)
Game theory :Prisoners’ dilemma payoff matrix
3 years
3 years
10 years
2 years
2 years
1 year
10 year
Both deny
One denies
other admits
Both admit
One denies, other admits
1 year
![Page 16: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/16.jpg)
Game Theory
Consider two firms, Alpha and Beta.
Each firm must decide whether to increase production capacity in the coming year.
The consequences of the firm’s actions are summarised below.
Beta
Do Not expand Expand
Do not expand $18, $18 $ 15, $ 20
Alpha
Expand $ 20, $15 $ 16, $ 16
![Page 17: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/17.jpg)
Game Theory (Cont..)
Consider pay off for Alpha
If Beta expands
and Alpha expands, profit = $16
and Alpha does not expand, profit= $ 15
If Beta does not expand
and Alpha expands, profit = $20
and Alpha does not expand, profit = $18
So it makes sense for Alpha to expand in both cases.
See previous slide
![Page 18: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/18.jpg)
Game Theory (Cont..)
Consider pay off for Beta
Say Alpha expands
Beta does not expand profit = $15
Beta expands profit = $16
Say Alpha does not expand
Beta does not expand profit = $18
Beta expands profit = $20
So it makes sense for Beta to expand in both cases
See earlier slide
![Page 19: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/19.jpg)
So the Nash equilibrium is that each firm expands its capacity.
At the Nash equilibrium, each player is doing the best it can, given the strategies of other players.
If each party expects the other to choose its Nash equilibrium strategy, then in fact both parties will choose their Nash equilibrium strategies
The Nash equilibrium does not necessarily correspond to the outcome that maximises the aggregate profit of the players.
![Page 20: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/20.jpg)
Beta
Do Not Expand Small Large
Do Not Expand 18, 18 15, 20 9, 18
Small 20, 15 16, 16 8, 12
Large 18, 9 12, 8 0, 0
Beta
Alpha
Equilibrium point is Small, Small
Alpha
![Page 21: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/21.jpg)
Game Tree for Sequential Capacity Expansion Game
Do Not Expand
Alpha
Small
Large
Beta
Small
Do not expand
Large
Beta
Small
Do not expand
Large
Beta
Small
Do not expand
Large
($18,$18)
($15,$20)
($9,$18)
($20,$15)
($16,$16)
($8,$12)
($18,$9)
($12,$8)
($0,$0)
If both firms decide simultaneously, the equilibrium is (Small, Small)
What happens if Alpha first decides?
![Page 22: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/22.jpg)
In a sequential move game, Alpha’s capacity choice has commitment value. It forces Beta into a corner.
By committing to a large capacity expansion, Alpha forces Beta into a position where Beta’s response yields the outcome that is most favourable to alpha.
So Alpha makes a large expansion while Beta does not expand.
The payoff is (18,9)
![Page 23: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/23.jpg)
- Consider only two firms in the market.
- They produce identical goods and charge the same prices.
- The sole strategic choice is the total amount they produce, Q1 + Q2
- The market price is that which enables both firms to sell all their output.
- Each firm’s optimal level of production is the best response to the level it expects its rivals to choose.
-This model applies to situations where firms must make production decisions in advance and are committed to selling all their output.
-This may be so if bulk of the production costs are sunk or it is costly to hold inventory.
Cournot Model
![Page 24: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/24.jpg)
Cournot Equilibrium
Suppose there are two players in the market.
For A, TC1 = 10 Q1
For B, TC2 = 10 Q2
Marginal cost = ?
Market demand is given by Q1+Q2 = 100 – P or P = 100 – (Q1+Q2)
At Cournot equilibrium,
P1* = 100 – Q1
* - Q2* (Q1* , Q2* are market clearing output)
Q1* is A’s profit maximising output given that it guesses B will produce Q2
*
Q2* is B’s profit maximising output given that it guesses A will produce Q1
*
![Page 25: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/25.jpg)
Assume that A guesses B will produce Q2g
Then A’s profit = Revenues - Total cost
= P1 Q1 - 10 Q1
= (100 – Q1-Q2g) Q1 – 10 Q1
= 100 Q1 – Q12 – Q2g Q1 – 10 Q1
Profit = 90 Q1 – Q12 – Q2g Q1
We differentiate and equate to zero to find out maxima/minima.
d (profit) / d Q1 = 90 – 2Q1 – Q2g
d 2(profit) / dQ12 = -2Q1 = always - ve
So it is a maxima point
90 – 2Q1 – Q2g = 0
2Q1 = 90 - Q2g
Q1 = 45 - .5 Q2g
![Page 26: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/26.jpg)
So if A expects B to increase its output, it will reduce the output and vice versa.
Similarly profit maximising value of Q2 = 45 - .5 Q1g
So Q1 = 45 - .5Q2g
Q2 = 45 - .5 Q1g
At equilibrium,
Q2g = 45 - .5 (45 - .5Q2g )
Q2g = 45 – 22.5 + .25 Q2g
0.75 Q2g = 22.5
Q2g = 22.5 /.75 = 30
Q1g = 45 - .5 (30) = 30
So at equilibrium, Q1* = Q2
* = 30
![Page 27: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/27.jpg)
Process of adjustment in Carnot equilibrium( Q2 = 45 -0.5*Q1)Q2 ,Q1 are both 40
Starting Q1 Starting Q2 Adjusting firm
Ending Q1 Ending Q2
40 40 1 25 40
25 40 2 25 32.5
25 32.5 1 28.75 32.5
28.75 32.5 2 28.75 30.63
28.75 30.63 1 29.69 30.63
![Page 28: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/28.jpg)
-Each firm selects a price and stands ready to meet all the demand for its products at that price.
-Each firm selects a price to maximise its own profits, given the price that it believes the other firm will select.
-When the firm’s products are perfect substitutes, price competition will be severe.
-Rivalry between the two firms is enough to achieve the perfectly competitive outcome.
-The Bertrand model applies to markets in which capacity is sufficiently flexible so that firms can meet all the demand that arises at the prices they announce.
-Firms expect all increases in sales will come through business stealing.
Bertrand Model
![Page 29: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/29.jpg)
P = 100 – (Q1 + Q2)
Cournot equilibrium is P = 100 – 30 – 30 = 40
But this is not the Bertrand equilibrium.
If B charges 40, A may charge 39 and grab the entire market, i.e., Q1 = 100 – P = 61
Profits for A in Cournot equilibrium = (40) (30) – (10) (30) = 900
Profits for B now = (39) (61) – (10) (61)
= (29) (61)
= 1769
![Page 30: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/30.jpg)
As long as both firms set prices that exceed marginal costs, one firm will have an incentive to undercut the other and grab the entire market. The only possibly equilibrium is P1 = P2 = marginal cost = 10.
In Bertrand model, rivalry between the two firms is enough to achieve the perfectly competitive outcome.
Price competition will be fierce if the products are perfect substitutes.
When products are differentiated, competition will be less intense.
![Page 31: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/31.jpg)
Differences between Cournot and Bertrand model
Cournot competitors can be thought of as choosing capacities and then competing as price setters given the capacities chosen earlier.
The Cournot model applies most naturally to markets when firms must make production decisions in advance and are committed to selling all of their output.
This might occur because the bulk of the production costs are sunk or because it is costly to hold inventory.
So prices will adjust more quickly than quantities. Each firm will try to keep sales equal to planned production volumes.
Business stealing is not an option.
![Page 32: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/32.jpg)
Bertrand model applies to markets in which capacity is sufficiently flexible.
Firms can meet all of the demand that arises at the prices they announce.
When products are substitutes, each firm believes it can steal business from its competitors through a small cut in price.
Firms expect all the increase in sales to come from business stealing.
In equilibrium, margins are driven to zero.
![Page 33: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/33.jpg)
Horizontally differentiated markets
Undercutting will not lead to loss of entire business.
Say Q1 = 63.42 - 3.08 P1 + 2.25 P2
Q2 = 49.52 – 5.48 P2 + 1.40 P1
A’s Marginal cost = 4.96
B’s Marginal cost = 3.94
A’s profit = (P1 – 4.96) (63.42 – 3.98 P1 + 2.25 P2g)
P1 = 10.44 + .2826 P2g
B’s profit = (P2g - 3.94) (49.52 – 5.48 P2 + 1.40 P1g)
P2 = 6.40 + .1277 P1g
Solving P1 = 12.72, P2 = 8.11
![Page 34: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/34.jpg)
(4)
Consider a market with two horizontally differentiated firms, X and Y. Each has constant marginal cost of $20. Demand functions are:
Qx = 100 – 2 Px + 1 Py
Qy = 100 – 2 Py + 1 Px
Calculate the Bertrand equilibrium.
= (Px – 20) (100 – 2 Px + Pyg)
= (Py – 20) (100 – 2 Py + Pxg)Differentiating with respect to P we get,
100 – 4Px + Pyg + 40 = 0
100 – 4Py + Pxg + 40 = 0
x
y
0x
x
d
d
0y
y
d
d
![Page 35: Market structure and competition By A.V. Vedpuriswar](https://reader036.vdocuments.mx/reader036/viewer/2022081603/56649e8b5503460f94b90c16/html5/thumbnails/35.jpg)
At equilibrium, Px = Pxg , Py = Pyg
100 – 4Pxg+ Pyg + 40 = 0
100 – 4Pyg+ Pxg + 40 = 0
Or 400 – 16 Pyg+ 4Pxg + 160 = 0
Adding, we get
500 – 15 Pyg + 200 = 0
Pyg = 700/15, Pxg = 140 + 700/15 =700/15