We now move away from the fairly straightforward world of perfect competition and monopoly into the complex and uncertain world of oligopoly and duopoly. We find that many market structures tend towards being an oligopoly as time progresses. They are frequently fascinating markets to look at!

An oligopoly is a market dominated by a few producers, each of which has control over the market. It is an industry where there is a high level of market concentration. However, oligopoly is best defined by the conduct (or behaviour) of firms within a market rather than its market structure.

The concentration ratio measures the extent to which a market or industry is dominated by a few leading firms. Normally an oligopoly exists when the top five firms in the market account for more than 60% of total market demand/sales.

Characteristics of an oligopoly

There is no single theory of how firms determine price and output under conditions of oligopoly. If a price war breaks out, oligopolists will produce and price much as a perfectly competitive industry would; at other times they act like a pure monopoly. But an oligopoly usually exhibits the following features:

1. Product branding: Each firm in the market is selling a branded (differentiated) product
2. Entry barriers: Significant entry barriers into the market prevent the dilution of competition in the long run which maintains supernormal profits for the dominant firms. It is perfectly possible for many smaller firms to operate on the periphery of an oligopolistic market, but none of them is large enough to have any significant effect on market prices and output
3. Interdependent decision-making: Interdependence means that firms must take into account likely reactions of their rivals to any change in price, output or forms of non-price competition. In perfect competition and monopoly, the producers did not have to consider a rival’s response when choosing output and price.
4. Non-price competition: Non-price competition s a consistent feature of the competitive strategies of oligopolistic firms. Examples of non-price competition includes:

1. Free deliveries and installation
2. Extended warranties for consumers and credit facilities
3. Longer opening hours (e.g. supermarkets and petrol stations)
4. Branding of products and heavy spending on advertising and marketing
5. Extensive after-sales service
6. Expanding into new markets + diversification of the product range

The kinked demand curve model of oligopoly

The kinked demand curve model developed first by the economist Paul Sweezy assumes that a business might face a dual demand curve for its product based on the likely reactions of other firms in the market to a change in its price or another variable. The common assumption of the theory is that firms in an oligopoly are looking to protect and maintain their market share and that rival firms are unlikely to match another’s price increase but may match a price fall. I.e. rival firms within an oligopoly react asymmetrically to a change in the price of another firm.

If a business raises price and others leave their prices constant, then we can expect quite a large substitution effect away from this firm making demand relatively price elastic. The business would then lose market share and expect to see a fall in its total revenue.

If a business reduces price but other firms follow suit, the relative price change is much smaller and demand would be inelastic in respect of the price change. Cutting prices when demand is inelastic also leads to a fall in total revenue with little or no effect on market share.

The kinked demand curve model therefore makes a prediction that a business might reach a stable profit-maximising equilibrium at price P1 and output Q1 and have little incentive to alter prices.

The kinked demand curve model predicts periods of relative price stability under an oligopoly with businesses focusing on non-price competition as a means of reinforcing their market position and increasing their supernormal profits.

Short-lived price wars between rival firms can still happen under the kinked demand curve model. During a price war, firms in the market are seeking to snatch a short term advantage and win over some extra market share.

There is limited evidence for the kinked demand curve model. The theory can be criticised for not explaining why firms start out at the equilibrium price and quantity. But it is one model of how firms in an oligopoly might behave if they have to consider the likely responses of their rivals.

The importance of non-price competition under oligopoly

Non-price competition assumes increased importance in oligopolistic markets. Non-price competition involves advertising and marketing strategies to increase demand and develop brand loyalty among consumers. Businesses will use other policies to increase market share:

1. Better quality of service including guaranteed delivery times for consumers and low-cost servicing agreements
2. Longer opening hours for retailers, 24 hour telephone and online customer support
3. Extended warranties on new products
4. Discounts on product upgrades when they become available in the market
5. Contractual relationships with suppliers - for example the system of tied houses for pubs and contractual agreements with franchises (exclusive distribution agreements)

Advertising spending runs in millions of pounds for many firms. Some simply apply a profit maximising rule to their marketing strategies. A promotional campaign is profitable if the marginal benefit (or revenue) from any extra sales exceeds the cost of the advertising campaign and marginal costs of producing an increase in output. However, it is not always easy to measure accurately the incremental sales arising from a specific advertising campaign. Other businesses see advertising simply as a way of increasing sales revenue. If persuasive advertising leads to an outward shift in demand, consumers are willing to pay more for each unit consumed. This increases the potential consumer surplus that a business might extract.

Relatively high spending on marketing is important for new business start-ups (consider the huge and often extravagant sums spent on marketing by the emerging dot-coms during the internet mania of the late 1990s and into 2000) and also by firms trying to break into an existing market where there is consumer or brand loyalty to the existing products in the market.

Price leadership – tacit collusion

Another type of oligopolistic behaviour is price leadership. This is when one firm has a clear dominant position in the market and the firms with lower market shares follow the pricing changes prompted by the dominant firm. We see examples of this with the major mortgage lenders and petrol retailers where most suppliers follow the pricing strategies of leading firms. If most of the leading firms in a market are moving prices in the same direction, it can take some time for relative price differences to emerge which might cause consumers to switch their demand.

Firms who market to consumers that they are “never knowingly undersold” or who claim to be monitoring and matching the cheapest price in a given geographical area are essentially engaged in tacit collusion. Does the consumer really benefit from this?

Tacit collusion occurs where firms undertake actions that are likely to minimise a competitive response, e.g. avoiding price cutting or not attacking each other’s market

Explicit collusion under oligopoly

It is often observed that when a market is dominated by a few large firms, there is always the potential for businesses to seek to reduce market uncertainty and engage in some form of collusive behaviour. When this happens the existing firms decide to engage in price fixing agreements or cartels. The aim of this is to maximise joint profits and act as if the market was a pure monopoly. This behaviour is deemed illegal by the UK and European competition authorities. But it is hard to prove that a group of firms have deliberately joined together to raise prices.

Price fixing

Collusion is often explained by a desire to achieve joint-profit maximisation within a market or prevent price and revenue instability in an industry. Price fixing represents an attempt by suppliers to control supply and fix price at a level close to the level we would expect from a monopoly.

To fix prices, the producers in the market must be able to exert control over market supply. In the diagram below a producer cartel is assumed to fix the cartel price at output Qm and price Pm. The distribution of the cartel output may be allocated on the basis of an output quota system or another process of negotiation.

Although the cartel as a whole is maximising profits, the individual firm’s output quota is unlikely to be at their profit maximising point. For any one firm, within the cartel, expanding output and selling at a price that slightly undercuts the cartel price can achieve extra profits. Unfortunately if one firm does this, it is in each firm’s interests to do exactly the same. If all firms break the terms of their cartel agreement, the result will be an excess supply in the market and a sharp fall in the price. Under these circumstances, a cartel agreement might break down.

Collusion in a market or industry is easier to achieve when:

1. There are only a small number of firms in the industry and barriers to entry protect the monopoly power of existing firms in the long run.
2. Market demand is not too variable
3. Demand is fairly inelastic with respect to price so that a higher cartel price increases the total revenue to suppliers in the market
4. Each firm’s output can be easily monitored – this enables the cartel more easily to control total supply and identify firms who are cheating on output quotas.

Possible break-downs of cartels

Most cartel arrangements experience difficulties and tensions and some producer cartels collapse completely. Several factors can create problems within a collusive agreement between suppliers:

• Enforcement problems: The cartel aims to restrict total production to maximize total profits of members. But each individual member of the cartel finds it profitable to raise its own production. It may become difficult for the cartel to enforce its output quotas. There may be disputes about how to share out the profits. Other firms – not members of the cartel – may opt to take a free ride by producing close to but just under the cartel price.
• Falling market demand during a slowdown or recession creates excess capacity in the industry and puts pressure on individual firms to cut prices to maintain their revenue. There are good recent examples of this in international commodity markets including the collapse of the coffee export cartel and some of the problems that have faced OPEC in recent years
• The successful entry of non-cartel firms into the industry undermines a cartel’s control of the market – e.g. the emergence of online retailers in the book industry in the mid 1990s
• The exposure of illegal price fixing by market regulators – e.g. the severe fines imposed on vitamin producers by the European Commission in the autumn of 2001 and recent investigations of price-fixing by the UK Office of Fair Trading.