Market Power & Oligopolies (DP IB Economics)
Revision Note
Written by: Steve Vorster
Reviewed by: Jenna Quinn
Market Power in Oligopoly Market Structures
Most markets are imperfectly competitive
Most imperfectly competitive industries operate in an oligopoly market structure
E.g., Banks, insurance companies, department stores, supermarkets, petrol retailers, sport stores etc.
Market power refers to the ability of a firm to influence and control the conditions in a specific market, allowing them to have a significant impact on price, output, and other market variables
The level of market power is high for oligopoly firms
Oligopoly firms have significant market power, a large market share and the concentration ratio of the top 5 firms is usually high
There is significant market failure in oligopoly market structures
Governments regulate and intervene in mergers and acquisitions in order to ensure (in many economies) that no single firm gains more than 25% market share
Characteristics of an Oligopoly Market
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Measuring Concentration Ratios
The most commonly used concentration ratios in the UK are the five-firm, ten-firm, & twenty-firm concentration ratios
A five-firm concentration ratio of around 60% is considered to be an oligopoly
A one-firm concentration ratio of 100% would be a pure monopoly
many government regulators define a monopoly as a firm with more than 25% market share
They act to prevent mergers or acquisitions from taking place which would give one firm more than 25% market share
Worked Example
The following table shows the value of UK Supermarket sales for the 3 months to the 31st March 2022.
Company | Value of Sales | Company | Value of Sales |
Tesco | 136.5 | Waitrose | 24 |
Morrisons | 55 | Asda | 77.5 |
The Co-operative | 30 | Lidl | 33 |
Sainsbury's | 75 | Iceland | 15 |
Aldi | 44 | Others | 10 |
Calculate the five-firm concentration ratio. Show your working. [2]
Answer:
Step 1: Identify the top five firms by value of sales & add the value of their sales together
Tesco (136.5) + Asda (77.5) + Sainsbury's (75) + Morrisons (55) + Aldi (44)
(1 mark for any correct working)
Step 2: Calculate the percentage of total sales that the top five firms have
(1 mark)
Reasons For Collusive & Non-collusive Behaviour
Collusive behaviour in oligopolies occurs when firms cooperate to fix prices & restrict output
They cease to compete as vigorously as they can
The incentive to collude is high
Non collusive behaviour in oligopolies occurs when firms actively compete to maintain/increase market share
Price wars may break out occasionally between competitors
Little is to be gained as competitors can quickly follow each others actions resulting with very little change in market share - but a significant loss in profits due to the lower prices generated by the price war
A collusive oligopoly removes competition and causes the firms in the industry to act as a monopoly
Diagram Analysis
Five firms with a concentration ratio of 80% meet secretly and agree to fix prices at a particular level
The five firms present in the market as a single firm
The firm produces at the profit maximisation level of output where MC = MR (Q1)
At this level the AR (P1) > AC (C1)
The collusive oligopoly is making higher levels of abnormal profit
Reasons for Collusion
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Few firms/competitors |
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Similar costs |
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Similar revenue |
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High barriers to entry |
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Ineffective regulation |
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Brand loyalty |
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Types of Collusion
Collusion can be overt or tacit
The net effect of collusion is that a group of firms end up acting more like a monopoly in the market
Overt collusion occurs when firms explicitly agree to limit competition or raise prices (price fixing)
A cartel is the most restrictive form of collusion & is illegal in most countries
The consequences of overt collusion include:
Higher prices for consumers
Less output in the market
Poor quality products and/or customer service
Less investment in innovation
Overt collusion often happens in the following ways
Price fixing
Setting output quotas which limit supply & naturally results in price increases
Agreements to block new firms from entering the industry
Agreements to pay suppliers the same price thereby driving down prices in the supply chain (monopsony power)
Tacit collusion occurs when firms avoid formal agreements but closely monitor each other's behaviour usually following the lead of the largest firm in the industry
The most common form of tacit collusion is price leadership
This occurs when firms monitor the price of the largest firm in the industry & then adjust their prices to match
It is difficult for regulators to prove that collusion has occurred
It provides similar benefits to firms as overt collusion, but perhaps not to the same degree
It has similar consequences for consumers as overt collusion, but perhaps not to the same degree
Game Theory - Interdependence Between Oligopoly Firms
Game theory is a mathematical framework which is used by firms to ensure optimal decisions are made in a strategic setting where there is a high level of interdependence (such as in oligopoly markets)
Any game has three elements
The players - (firms)
The strategies available to the players
The payoffs (outcomes) that each player receives for each combination of strategies
It was first illustrated using a simple model called The Prisoners Dilemma
Two criminals are caught after a train robbery (Carol & Doug)
The prosecutor does not have much evidence
The criminals are guilty but have agreed with each other that they will deny all involvement
The prosector wants one (or both) to confess
The strategies & payoffs available to the prisoners are presented in a payoff matrix
A prisoner's dilemma payoff matrix which illustrates game theory
Diagram Analysis
If Carol & Doug stick to their plan & deny involvement, they each get 3 years jail time
If Doug confesses & indicates Carol's involvement, then Doug gets a lenient sentence of 1 year & Carol gets 10 years
If Carol confesses & indicates Doug's involvement, then Carol gets a lenient sentence of 1 year & Doug gets 10 years
There is a strong incentive to collude as it will yield the most beneficial outcome for Carol and Doug (3 years each)
Fearing the worst, both players decide to confess and receive 5 years each
This outcome is called the dominant strategy as it carries the least risk
How Firms Use Game Theory
Firms typically use game theory in the following situations:
When making decisions to raise or lower prices
When making decisions about new advertising & branding initiatives
When making decisions about investment in product innovation
When making decisions on product bundling e.g. combined phone & broadband packages
Below is a payoff matrix representing the strategic options available to Burger King & McDonald's when making advertising decisions
The £ payoffs represent the likely profits for each combination of choices selected
A payoff matrix which illustrates the strategies & payoffs available to firms when they are deciding to advertise or not to advertise
Diagram Analysis
If Burger King & McDonald's collude & agree not to advertise (top left), they can each enjoy £3 bn. in profits
There is a strong incentive to collude
If Burger King advertises & McDonald's does not, then Burger King's profits are £5 bn. & McDonald's are £1 bn.
If McDonald's advertises & Burger King does not, then McDonald's profits are £5 bn. & Burger King's are £1 bn.
Both firms decide to advertise & receive £2 bn. of profits each
This outcome is called the dominant strategy as it carries the least risk
The risk of collusion is that one player will cheat and by doing so, get ahead
Worked Example
The grid below shows the possible pricing strategies of two coffee companies. The Bean and Black Gold. Assuming that demand is price inelastic.
Black Gold's price | The Bean's price | ||
High | Low | ||
High | A | B | |
Low | C | D |
Which strategy in the grid would maximise the revenue of the two firms? Explain your answer. [4]
Answer:
Step 1: Use the information provided to select the correct option
A (1 mark)
Step 2: Explain your answer using economic knowledge
With reference to the revenue rule, firms whose demand is price inelastic should raise their price to maximise revenue. Due to the fact that consumers consider coffee a necessity, they will continue to pay the high prices. (1 mark)
However, there is a strong likelihood that firms will charge a low price (D) as the payoff matrix carries the lowest risk. (1 mark)
If firms do collude to charge the high price, then B & C represent higher revenue for any firm that first decides to cheat on the agreement (lower their price so that heir market share will increase) (1 mark)
Price Competition
Firms in an oligopoly market engage in three types of price competition
Price wars: occur when competitors repeatedly lower prices to undercut each other in an attempt to gain or increase market share. This often occurs when there is a lower level of non-price competition & where firms find it difficult to collude (either formal or tacit)
Predatory pricing: this is the practice of lowering prices when a new competitor joins the industry in order to drive them out. Prices are often lowered to a point below the cost of production. Once they have left the market, prices are raised again. This pricing strategy is usually illegal as it is anticompetitive
Limit pricing: occurs when firms set a limit on how high the price will go in the industry. A lower price reduces profit & disincentivize other firms from joining the industry. The greater the barriers to entry the higher the limit price is likely to be as firms are already disincentivized
Types of Non-price Competition
Firms engage in a wide range of non-price competition strategies
The aim is to increase product differentiation, develop or increase brand loyalty, & to increase market share
A Range of Strategies used in Non-price Competition
Loyalty cards & rewards | Branding | Packaging | Celebrity/influencer endorsement |
Corporate sponsorship e.g. Nike sponsoring Rafael Nadal | After sales service | Delivery policies | Product warranties |
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