6.1.2

Perfect Competition

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Perfect Competition

A market being perfectly competitive has a number of implications for firms in the industry.

Characteristics of perfect competition

Characteristics of perfect competition

  • Firms are in perfect competition when the following conditions hold:
    • Lots of firms produce identical (homogenous) products.
    • Many buyers and many sellers.
    • Sellers and buyers have perfect and relevant information to make rational decisions.
    • Firms can enter and leave the market without restrictions (no barriers to entry or exit).
    • Firms aim to maximise profit.
Market price in perfect competition

Market price in perfect competition

  • The market price is determined solely by supply and demand in the entire market.
  • A perfectly competitive firm must be a very small player in the overall market so that it can increase or decrease output without noticeably affecting the overall quantity supplied and price in the market.
  • So, firms are price takers.
Allocative efficiency in perfect competition

Allocative efficiency in perfect competition

  • The demand curve is equal to marginal utility (MU) under perfect competition.
  • The supply curve is equal to the marginal cost (MC).
  • So, if the forces of demand and supply determine equilibrium, the equilibrium price and quantity will be where MU=MC.
  • This is allocatively efficient.
  • If there are externalities, perfect competition may not be allocatively efficient, if the long run equilibrium is price is equal to the marginal private cost.
Productive efficiency in perfect competition

Productive efficiency in perfect competition

  • Firms in perfect competition are productively efficient, assuming there are no economies of scale.
  • They will produce where the average cost is minimised because this is the only place normal profit can be made.
  • But if economies of scale exist, a monopoly could be more efficient than a perfectly competitive industry with many firms.
Dynamic efficiency in perfect competition

Dynamic efficiency in perfect competition

  • Firms do not make supernormal profits in perfect competition.
  • They may not be able to invest in R&D and in new technologies, so this may not be dynamically efficient.

Illustrating Perfect Competition

The sequence of diagrams below illustrates how a market in perfect competition might respond to changes to return to its long-run equilibrium.

1) Initial equilibrium

1) Initial equilibrium

  • Here, the market is in equilibrium.
  • Firms are profit maximising where MR = MC and normal profit is being made by producers because AR = AC at this point.
  • Firms are price takers as they must accept the price reached at the industry equilibrium.
2) A change

2) A change

  • Here, the average cost for firms has fallen.
  • The cost of a space at the market has fallen, for example, meaning AC would fall but MC would not.
  • Firms are now making supernormal profit in the short-run.
3) Returning to equilibrium

3) Returning to equilibrium

  • Supernormal profits and very low barriers to entry would attract new firms to the market.
  • This would shift supply to the right and reduce the equilibrium price.
  • So the supernormal profit is 'eroded' away very quickly and firms in the industry return to making normal profit, albeit at a lower price.
Jump to other topics
1

Introduction to Markets

1.1

Nature of Economics

1.1.1Economics as a Social Science1.1.2Positive & Normative Economic Statements1.1.3The Economic Problem1.1.4Resources1.1.5Production Possibility Frontiers1.1.6Specialisation & Division of Labour1.1.7Types of Economies1.1.8End of Topic Test - Nature of Economics1.1.9Application Questions - Nature of Economics
1.2

How Markets Work

1.2.1Rational Decision Making1.2.2Demand1.2.3Elasticities of Demand1.2.4Elasticities of Demand 21.2.5Elasticity & Revenue1.2.6Supply1.2.7Elasticity of Supply1.2.8Price Determination1.2.9Price Mechanism1.2.10Consumer & Producer Surplus1.2.11Indirect Taxes & Subsidies1.2.12A-A* (AO3/4) - Taxing Prices or Quantities?1.2.13Alternative View of Consumer Behaviour1.2.14End of Topic Test - Markets1.2.15A-A* (AO3/4) - Markets
2

Market Failure

2.1

Market Failure

2.1.1Types of Market Failure2.1.2Externalities2.1.3The Deadweight Welfare Loss of Externalities2.1.4A-A* (AO3/4) - The Externalities of Education2.1.5Public Goods2.1.6Information Gaps2.1.7End of Topic Test - Market Failure2.1.8Application Questions - Market Failure
2.2

Government Intervention

2.2.1Government Intervention in Markets2.2.2Subsidies & Price Controls2.2.3Pollution Permits & Regulation2.2.4A-A* (AO3/4) - European Emissions Trading2.2.5State Provision & Information Provision2.2.6Government Failure2.2.7End of Topic Test - Government Intervention2.2.8A-A* (AO3/4) - Government Intervention
3

The UK Macroeconomy

3.1

Measures of Economic Performance

3.1.1Measuring Economic Growth3.1.2National Income Data3.1.3Inflation3.1.4Causes of Inflation3.1.5Consequences of Inflation3.1.6Employment & Unemployment3.1.7Causes & Impact of Unemployment3.1.8A-A* (AO3/4) - Hysteresis3.1.9Balance of Payments3.1.10Current Account Deficit & Imbalances3.1.11End of Topic Test - Economic Performance3.1.12Application Questions Macroeconomy
3.2

Aggregate Demand

3.2.1Aggregate Demand3.2.2Consumption3.2.3Investment3.2.4Government Expenditure3.2.5Net Trade3.2.6End of Topic Test - Aggregated Demand3.2.7Application Questions - AD
3.3

Aggregate Supply

3.3.1Aggregate Supply3.3.2End of Topic Test - Aggregated Supply3.3.3A-A* (AO3/4) -Aggregate Supply
3.4

National Income

3.4.1National Income3.4.2Injections & Withdrawals3.4.3Equilibrium Level of Real National Output3.4.4Multiplier Effect3.4.5End of Topic Test - National Income3.4.6Application Questions - National Income
3.5

Economic Growth

3.5.1Causes of Economic Growth3.5.2Output Gaps3.5.3Business Cycle3.5.4Impact of Economic Growth3.5.5End of Topic Test - Economic Growth3.5.6A-A* (AO3/4) - Growth
4

The UK Economy - Policies

4.1

Macroeconomic Objectives & Policies

4.1.1Possible Objectives4.1.2Demand-Side Policies - Monetary4.1.3Demand-Side Policies - Monetary 24.1.4A-A* (AO3/4) - The Future of Interest Rates4.1.5Demand-Side Policies - Fiscal4.1.6Demand-Side Policies in 2007-084.1.7Strengths & Weaknesses of Demand Side4.1.8Supply-Side Policies4.1.9Supply-Side Policies 24.1.10Conflicts Between Objectives4.1.11A-A* (AO3/4) - Conflicting Incentives4.1.12Phillips Curve4.1.13End of Topic Topic - Policies & Objectives4.1.14Application Questions - UK Policies
5

Business Behaviour

5.1

Business Growth

5.1.1Size & Types of Firms5.1.2Business Growth5.1.3Pros & Cons of External Expansion5.1.4Demergers5.1.5End of Topic Test - Business Growth5.1.6A-A* (AO3/4) - Business Growth
5.2

Business Objectives

5.2.1Business Objectives5.2.2End of Topic Test - Business Objectives5.2.3Application Questions - Business Objectives
5.3

Revenues, Costs & Profits

5.3.1Revenue5.3.2Costs5.3.3Economies & Diseconomies of Scale5.3.4Profits5.3.5Profits 25.3.6End of Topic Test - Revenue, Costs & Profits5.3.7A-A* (AO3/4) - Revenue, Costs & Profit
6

Market Structures

6.1

Market Structures

6.1.1Efficiency6.1.2Perfect Competition6.1.3Perfect Competition 26.1.4Monopolistic Competition6.1.5Oligopolies6.1.6The Prisoner's Dilemma6.1.7Collusion in Oligopolistic Markets6.1.8A-A* (AO3/4) - Which Factors Affect Collusion?6.1.9Monopolies6.1.10Price Discrimination6.1.11Monopsony6.1.12A-A* (AO3/4) - Models in Economics6.1.13Contestability6.1.14Benefits of Contestability6.1.15End of Topic Test - Market Structures6.1.16Application Questions - Market Structures6.1.17A-A* (AO3/4) - Cereal Collusion
6.2

Labour Market

6.2.1Demand for Labour6.2.2Supply of Labour6.2.3Labour Market Imperfections6.2.4A-A* (AO3/4) - Labour Productivity & Unemployment6.2.5A-A* (AO3/4) - What Level of Unionisation is Good?6.2.6Wage Determination6.2.7Elasticity of Labour Supply & Demand6.2.8Intervention in Setting Wages6.2.9End of Topic Test - Labour Market6.2.10A-A* (AO3/4) - Labour Markets
6.3

Government Intervention

6.3.1Reasons for Government Intervention6.3.2Government Promotion of Competition6.3.3Usefulness of Competition Policy & Examples6.3.4A-A* (AO3/4) - Modern Competition Policy6.3.5Privatisation6.3.6Government Regulation6.3.7A-A* (AO3/4) - Nationalisation vs Privatisation6.3.8Government Protection of Suppliers and Employees6.3.9Impact of Government Intervention6.3.10End of Topic Test - Government Intervention6.3.11Application Questions - Government Intervention
7

A Global Perspective

7.1

International Economics - Globalisation & Trade

7.1.1Globalisation7.1.2Globalisation for LEDCs7.1.3Globalisation for MEDCs7.1.4Specialisation & Trade7.1.5Pattern of Trade7.1.6Terms of Trade7.1.7Trading Blocs7.1.8UK, EU & WTO7.1.9End of Topic Test - Globalisation & Trade7.1.10A-A* (AO3/4) - Globalisation & Trade
7.2

International Economics - Currency

7.2.1Merged Currency7.2.2Restrictions on Free Trade7.2.3Arguments for Protectionism7.2.4Arguments Against Protectionism7.2.5Balance of Payments7.2.6Balance of Payments 27.2.7Floating Exchange Rates7.2.8Fixed Exchange Rate7.2.9International Competitiveness7.2.10End of Topic Test - International Economy7.2.11Application Questions - International Economics
8

Finance & Inequality

8.1

Poverty & Inequality

8.1.1Absolute & Relative Poverty8.1.2Inequality8.1.3Inequality 28.1.4Lorenz Curve8.1.5Government Policy on Poverty8.1.6End of Topic Test - Poverty & Inequality8.1.7A-A* (AO3/4) - Inequality & Poverty
8.2

Emerging & Developing Economies

8.2.1Measures of Development8.2.2Factors Influencing Growth & Development8.2.3Barriers to Development8.2.4Barriers to Development 28.2.5A-A* (AO3/4) - The Bottom Billion8.2.6Development Strategies8.2.7Interventionist Strategies8.2.8Aid8.2.9International Institutions8.2.10International Institutions 28.2.11End of Topic Test - Emerging & Developing8.2.12Application Questions - Developing Countries
8.3

The Financial Sector

8.3.1Role of Financial Markets8.3.2Market Failure in the Financial Sector8.3.3Role of Central Banks8.3.4End of Topic Test - The Financial Sector8.3.5A-A* (AO3/4) - Financial Sector
8.4

Role of the State in the Macroeconomy

8.4.1Public Expenditure8.4.2Taxation8.4.3Public Sector Finances8.4.4End of Topic Test - Role of the State8.4.5Application Questions - Role of the State
9

Examples of Global Policy

9.1

International Policies

9.1.1Global Debt & Deficit Policies9.1.2Poverty & Inequality Policies9.1.3Changes in Interest Rates9.1.4Competitiveness Policies9.1.5End of Topic Test - International Policies9.1.6A-A* (AO3/4) - International Policies
9.2

Policy Responses to Shocks

9.2.1International Tax Policies9.2.2Problems for Policymakers9.2.3End of Topic Test - Policy Responses9.2.4Application Questions - Policy Responses

Practice questions on Perfect Competition

Can you answer these? Test yourself with free interactive practice on Seneca — used by over 10 million students.

  1. 1
    Which of the following are characteristics of perfect competition?True / false
  2. 2
    Which of these are characteristics of perfect competition?True / false
  3. 3
    Conditions for perfect competition:Fill in the list
  4. 4
    Assuming a firm is a price taker in perfect competition, which of the following is true in the short-run and long-run?Multiple choice
  5. 5
    Which of these is perfect competition unlikely to achieve?Multiple choice
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Efficiency

Perfect Competition 2