Oligopoly: Definition, Characteristics, Examples

Oligopoly: Definition, Characteristics, Examples

oligopoly definition

Oligopoly Definition

The term Oligopoly derives from the Latin ‘olígoi’ – meaning “few”, and ‘pōléō’ – meaning “to sell”. So, translated, it means ‘few sellers’. This is one of the main characteristics of an oligopoly – alongside 5 others which we will discuss below.

In economics, an oligopoly is defined as a type of market structure where two or more firms have market control. Combined, they are able to dictate prices and supply. Yet, they are unable to influence the market on their own.

Key Points
  1. An oligopoly is a type of market structure where two or more firms have significant market power. Collectively, they have the ability to dictate prices and supply
  2. Generally, a market is considered an oligopoly when 50 percent of the market is controlled by the leading 4 firms.
  3. An oligopoly can be identified using either the concentration ratio, or the Herfindahl-Hirschman Index.

Firms in an oligopoly can have varying degrees of market share. This could be as significant as 50 percent, or, as little as 5 percent. The point is that the oligopoly is characterised by a few firms no matter their size – as long as a handful of them have enough power to dictate supply and demand.

Oligopolies are also characterised by their interdependent. In other words, they are highly responsive to competitors actions. For instance, if one firm reduces prices, all the others will follow suit to maintain their position in the market.

Characteristics of an Oligopoly

There are 6 main characteristics of an oligopoly. Let us look at these below:

1. A Few Firms with Large Market Share

A market may have thousands of sellers, but if the top 5 firms have a combined market share of over 50 percent, it can be classified as an oligopolistic market. This is because the power is concentrated between a few sellers who are able to exercise power over the market.

2. High Barriers to Entry

Oligopolistic firms maintain their position through a number of barriers to entry. For instance, brand loyalty, patents, and high start-up costs are but to name a few. These make it difficult for new entrants to build a presence in the market and attract customers. In industries such as retail – brand loyalty is a significant barrier to overcome.

These barriers to entry make it difficult for new firms to join and sets it apart from perfect competition. As a result, these barriers to entry allow oligopolies to make higher profits due to limited competition.

3. Interdependence

Any action a firm takes in an oligopolistic market will strongly affect the actions of its competitors. As a result, we have what is often referred to as the ‘Prisoners Dilemma’, under Game Theory. For those who are not familiar with these terms: an oligopolistic firm will operate based on how they believe competitors will react. In other words, Company A expects Company X to reduce its prices, so will do so as well.

This can be sub-optimal as it reduces the power of a competitive market. For example, if Apple was to reduce the price of its iPhone by $200, Samsung would likely follow suit. So when Apple looks to take that decision, they will consider how they will benefit. They won’t receive a boost in demand because the competition is also the same price, so any initial benefit is lost. Often this can lead oligopolistic firms to just maintain the status quo and keep prices constant.

4. Each Firm Has Little Market Power In Its Own Right

Leading on from interdependence; each firm has little market power, because other firms are quick to take advantage. For example, an oligopolistic firm cannot raise prices in fear that customers will flee to its competitors. One oligopolistic firm cannot dictate prices or supply because competitors are equally as ‘powerful’. On an individual basis, this keeps the firm in check. Yet it equally incentivises collusion as one firm is unable to get ahead.

5. Higher Prices than Perfect Competition

Under perfect competition, prices are just above marginal cost, leaving firms with small profits – if any. As oligopolies have combined market power, they tend to keep prices higher to obtain larger profits.

If any firms were to reduce prices, others would also follow suit, thereby reducing profits for all. This is where it becomes tricky in distinguishing between collusion and a natural state of oligopolistic competition. Do firms naturally keep prices higher due to fear that their actions will reduce their profits? Or, do they collude to keep prices and profits high?

6. More Efficient

Oligopolistic firms benefit from high levels of market share. At the same time, they benefit from economies of scale – meaning it can produce at a lower cost. For instance, there are markets that have high fixed costs such as car manufacturers. If new competitors want to enter, they have to spend millions on new factories and other infrastructure.

Consequently, this would increase costs for exisiting firms as the benefit they receive from economies of scale would decline. This means higher prices for customers and it is for this reason that such markets are better served under an oligopolistic market structure.

Examples of Oligopoly

There are many oligopoly examples in today’s society. In fact, the device you are using now may very well be part of an oligopoly. With that said, it is important to realise that an oligopoly is generally defined by its market concentration. In other words, a few firms control the market. Let us look at some examples below:

News Media as an Example of Oligopoly

News Media

In the US, the top 6 firms account for close to 90 percent of the mass media market: Walt Disney (DIS), Time Warner (TWX), CBS Corporation (CBS), Viacom (VIAB), NBC Universal, and News Corporation (NWSA).

Motor Vehicles as an Example of Oligopoly

Motor Vehicles in US

Collectively, all of: Ford, Chrysler, General Motors, and Toyota; have a collective market share of close to 60 percent in the US.

Mobile Phone Networks as an Example of Oligopoly

Mobile Phones

Apple, Samsung, and Huawei own a combined market share of over 50 percent of the entire global market.

Cereal Manufacturers as an Example of Oligopoly

Breakfast cereals

Combined, Kellogg’s, General Mills, Post, and Quaker own over 85 percent of the US cereal market.

Beer as an Example of Oligopoly


Anheuser-Busch InBev, SABMiller, Heineken International, and Carlsberg Group own over 70 percent of the global beer market.

Cellular Networks

The top four firms: Verizon (VZ), Sprint (S), AT&T (T), and T-Mobile (TMUS); own a combined 98 percent of the total US wireless network market.

Entertainment Industry as an Example of Oligopoly

Music Entertainment

The top 4 firms: Universal Music Group, Sony, BMG, Warner, and EMI Group; control close to 90 percent of the US market.

Oligopoly Graph – Kinked Demand Curve

The kinked demand curve is distinctive of an oligopolistic market. It shows how, at higher and lower prices, the elasticity of demand changes. As a result, prices remain relatively rigid.

Oligopoly Graph

Copyright: Boycewire

As we can we in the chart above, firms are unlikely to be incentivised to increase or decrease prices.

This is because increasing prices will significantly impact demand. As competitors keep their prices stable, the firm that increases prices will lose customers to cheaper rivals.

At the same time, reducing prices won’t increase demand. This is because price decreases will be met with fierce competition. In an oligopoly, when one firm reduces its prices, the others follow. In turn, any real gains in demand will be negligible.

Now let us take an example of how this works:

Your Business Competitor Result
You Increase Prices P ↑ Competitors ignore and keep prices their prices the same P = Elastic demand. Demand is highly sensitive to price, so a lot of your customers will go to the cheaper competitors.
You Decrease Prices P ↓ Competitors follow suit and reduce their prices Inelastic demand. As all other competitors follow, demand for your products hardly changes

How to Tell if a Market is an Oligopoly

Concentration Ratio

The concentration ratio comes in a number of forms: third-firm ratio, four-firm ratio, five-firm ratio, and six-firm ratio. From this, the concentration ratio calculates the market share of the top 3 to 6 firms in the market.

Let us take the automobile industry in the US as an example. If we are to do a four-firm ratio, we would take the leading four companies: General Motors, Toyota, Ford, and Chrysler. Then, we work out their combined market share:

General Motors: 17 percent
Toyota: 14.6 percent
Ford: 14.4 percent
Chrysler: 13 percent
Total: 59 percent

So according to the four-firm ratio, the automobile industries has a concentration of 59 percent. In turn, we can define this as an oligopoly. This is because for a four-firm ratio; anything over 50 percent could be considered an oligopoly. Similarly, for a five-firm ratio; anything over 60 percent could also be considered an oligopoly.

Herfindahl-Hirschman Index

The Herfindahl-Hirschman Index is a method by which we can tell how concentrated a market is. Most commonly, it is used by the US Department of Justice to consider when to take action in anti-competitive markets.

Quite simply, anything under a score of 1,500 is considered as a competitive marketplace. Anything between a HHI score of 1,500 and 2,500 is considered moderately competitive. And anything over 2,500 is extremely concentrated. For markets with a score of over 1,500; they would classify as an oligopoly, all the way up to 10,000 – which signals a monopoly.

How to Calculate the Herfindahl-Hirschman Index

The HHI is calculated by selecting each firm’s market share. The market share is then squared individually, with the results added together. This can be seen below:

HHI = Business1 ² + Business2 ² + Business3 ² + BusinessN ²

So let us now take an example.

  • Business 1 Market Share = 30 percent
  • Business 2 Market Share = 20 percent
  • Business 3 Market Share = 15 percent
  • Business 4 Market Share = 10 percent

The HHI is then calculated as: HHI = 30² + 20² + 15² + 10² = 900 + 400 + 225 + 100 = HHI 1625.

Oligopoly FAQs

What is an example of an oligopoly?

Cellular Networks
The top four firms in the US: Verizon (VZ), Sprint (S), AT&T (T), and T-Mobile (TMUS); own a combined 98 percent of the total wireless network market.

What are the characteristics of an oligopoly?

1. A Few Firms with Large Market Share
2. High Barriers to Entry
3. Interdependence
4. Each Firm Has Little Market Power In Its Own Right
5. Higher Prices than Perfect Competition
6. More Efficient

Is Apple an oligopoly?

In the mobile phone market, Apple is part of an oligopoly. To take a case in point, Apple, Samsung, and Huawei own a combined market share of over 50 percent of the entire global market.

Is Coca Cola an oligopoly?

Coca-Cola is an oligopoly in the fact that the firm itself owns other brands such as Fanta. The only real competitor of any significance is Pepsi, which owns other brands such as Tango. In turn, both Pepsi and Coca-Cola own the majority of the soft drinks market, therefore qualifying as an oligopoly.

About Paul

Paul Boyce is an economics editor with over 10 years experience in the industry. Currently working as a consultant within the financial services sector, Paul is the CEO and chief editor of BoyceWire. He has written publications for FEE, the Mises Institute, and many others.

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