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

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

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

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

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

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

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

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

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.

1Introduction to Markets

2Market Failure

2.1Market Failure

2.1.1Types of Market Failure

2.1.2Externalities

2.1.3The Deadweight Welfare Loss of Externalities

2.1.4A-A* (AO3/4) - The Externalities of Education

2.1.5Public Goods

2.1.6Information Gaps

2.1.7End of Topic Test - Market Failure

2.1.8Application Questions - Market Failure

2.2Government Intervention

2.2.1Government Intervention in Markets

2.2.2Subsidies & Price Controls

2.2.3Pollution Permits & Regulation

2.2.4A-A* (AO3/4) - European Emissions Trading

2.2.5State Provision & Information Provision

2.2.6Government Failure

2.2.7End of Topic Test - Government Intervention

2.2.8A-A* (AO3/4) - Government Intervention

3The UK Macroeconomy

3.1Measures of Economic Performance

3.1.1Measuring Economic Growth

3.1.2National Income Data

3.1.3Inflation

3.1.4Causes of Inflation

3.1.5Consequences of Inflation

3.1.6Employment & Unemployment

3.1.7Causes & Impact of Unemployment

3.1.8A-A* (AO3/4) - Hysteresis

3.1.9Balance of Payments

3.1.10Current Account Deficit & Imbalances

3.1.11End of Topic Test - Economic Performance

3.1.12Application Questions Macroeconomy

3.2Aggregate Demand

3.2.1Aggregate Demand

3.2.2Consumption

3.2.3Investment

3.2.4Government Expenditure

3.2.5Net Trade

3.2.6End of Topic Test - Aggregated Demand

3.2.7Application Questions - AD

3.3Aggregate Supply

3.3.1Aggregate Supply

3.3.2End of Topic Test - Aggregated Supply

3.3.3A-A* (AO3/4) -Aggregate Supply

3.4National Income

3.4.1National Income

3.4.2Injections & Withdrawals

3.4.3Equilibrium Level of Real National Output

3.4.4Multiplier Effect

3.4.5End of Topic Test - National Income

3.4.6Application Questions - National Income

3.5Economic Growth

3.5.1Causes of Economic Growth

3.5.2Output Gaps

3.5.3Business Cycle

3.5.4Impact of Economic Growth

3.5.5End of Topic Test - Economic Growth

3.5.6A-A* (AO3/4) - Growth

4The UK Economy - Policies

4.1Macroeconomic Objectives & Policies

4.1.1Possible Objectives

4.1.2Demand-Side Policies - Monetary

4.1.3Demand-Side Policies - Monetary 2

4.1.4A-A* (AO3/4) - The Future of Interest Rates

4.1.5Demand-Side Policies - Fiscal

4.1.6Demand-Side Policies in 2007-08

4.1.7Strengths & Weaknesses of Demand Side

4.1.8Supply-Side Policies

4.1.9Supply-Side Policies 2

4.1.10Conflicts Between Objectives

4.1.11A-A* (AO3/4) - Conflicting Incentives

4.1.12Phillips Curve

4.1.13End of Topic Topic - Policies & Objectives

4.1.14Application Questions - UK Policies

5Business Behaviour

5.1Business Growth

5.1.1Size & Types of Firms

5.1.2Business Growth

5.1.3Pros & Cons of External Expansion

5.1.4Demergers

5.1.5End of Topic Test - Business Growth

5.1.6A-A* (AO3/4) - Business Growth

5.2Business Objectives

5.2.1Business Objectives

5.2.2End of Topic Test - Business Objectives

5.2.3Application Questions - Business Objectives

5.3Revenues, Costs & Profits

5.3.1Revenue

5.3.2Costs

5.3.3Economies & Diseconomies of Scale

5.3.4Profits

5.3.5Profits 2

5.3.6End of Topic Test - Revenue, Costs & Profits

5.3.7A-A* (AO3/4) - Revenue, Costs & Profit

6Market Structures

6.1Market Structures

6.1.1Efficiency

6.1.2Perfect Competition

6.1.3Perfect Competition 2

6.1.4Monopolistic Competition

6.1.5Oligopolies

6.1.6The Prisoner's Dilemma

6.1.7Collusion in Oligopolistic Markets

6.1.8A-A* (AO3/4) - Which Factors Affect Collusion?

6.1.9Monopolies

6.1.10Price Discrimination

6.1.11Monopsony

6.1.12A-A* (AO3/4) - Models in Economics

6.1.13Contestability

6.1.14Benefits of Contestability

6.1.15End of Topic Test - Market Structures

6.1.16Application Questions - Market Structures

6.1.17A-A* (AO3/4) - Cereal Collusion

6.2Labour Market

6.2.1Demand for Labour

6.2.2Supply of Labour

6.2.3Labour Market Imperfections

6.2.4A-A* (AO3/4) - Labour Productivity & Unemployment

6.2.5A-A* (AO3/4) - What Level of Unionisation is Good?

6.2.6Wage Determination

6.2.7Elasticity of Labour Supply & Demand

6.2.8Intervention in Setting Wages

6.2.9End of Topic Test - Labour Market

6.2.10A-A* (AO3/4) - Labour Markets

6.3Government Intervention

6.3.1Reasons for Government Intervention

6.3.2Government Promotion of Competition

6.3.3Usefulness of Competition Policy & Examples

6.3.4A-A* (AO3/4) - Modern Competition Policy

6.3.5Privatisation

6.3.6Government Regulation

6.3.7A-A* (AO3/4) - Nationalisation vs Privatisation

6.3.8Government Protection of Suppliers and Employees

6.3.9Impact of Government Intervention

6.3.10End of Topic Test - Government Intervention

6.3.11Application Questions - Government Intervention

7A Global Perspective

8Finance & Inequality

8.1Poverty & Inequality

8.1.1Absolute & Relative Poverty

8.1.2Inequality

8.1.3Inequality 2

8.1.4Lorenz Curve

8.1.5Government Policy on Poverty

8.1.6End of Topic Test - Poverty & Inequality

8.1.7A-A* (AO3/4) - Inequality & Poverty

8.2Emerging & Developing Economies

8.2.1Measures of Development

8.2.2Factors Influencing Growth & Development

8.2.3Barriers to Development

8.2.4Barriers to Development 2

8.2.5A-A* (AO3/4) - The Bottom Billion

8.2.6Development Strategies

8.2.7Interventionist Strategies

8.2.8Aid

8.2.9International Institutions

8.2.10International Institutions 2

8.2.11End of Topic Test - Emerging & Developing

8.2.12Application Questions - Developing Countries

8.3The Financial Sector

8.3.1Role of Financial Markets

8.3.2Market Failure in the Financial Sector

8.3.3Role of Central Banks

8.3.4End of Topic Test - The Financial Sector

8.3.5A-A* (AO3/4) - Financial Sector

8.4Role of the State in the Macroeconomy

8.4.1Public Expenditure

8.4.2Taxation

8.4.3Public Sector Finances

8.4.4End of Topic Test - Role of the State

8.4.5Application Questions - Role of the State

9Examples of Global Policy

9.1International Policies

9.1.1Global Debt & Deficit Policies

9.1.2Poverty & Inequality Policies

9.1.3Changes in Interest Rates

9.1.4Competitiveness Policies

9.1.5End of Topic Test - International Policies

9.1.6A-A* (AO3/4) - International Policies

9.2Policy Responses to Shocks

9.2.1International Tax Policies

9.2.2Problems for Policymakers

9.2.3End of Topic Test - Policy Responses

9.2.4Application Questions - Policy Responses

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