The Deadweight Welfare Loss of Externalities

Examples of Externalities

Consumers under and over consume goods and services because they don't take into account the external benefit or cost of their consumption. Firms can under or overproduce goods because they don't account for externalities in their production.

Education

A good with positive consumption externalities is often called a merit good.
Education has a positive consumption externality, so it is a merit good.
In education the MSB>MPB, so it is under consumed in the free market below the socially optimal level.

Petrol cars

Petrol cars have negative consumption externalities. This means that they are demerit goods.
Demerit goods are over consumed in the free market. This leads to a deadweight welfare loss to society.

Absence of property rights

The absence of property rights means that it is not clear who owns what.
For example, it is not clear who owns the environment or air. This can lead firms to pollute more than is optimal because they do not account for external costs.
Ronald Coase found that allocating property rights is one way to stop market failures from happening. This is called Coase Theorem.
The absence of property rights can lead to market failure.

Renewable energy

Renewable energy has positive production externalities.
It can replace the use of fossil fuels which can damage the environment - the opportunity cost would be using something negative instead of something neutral.
Governments have subsidised renewable energy (like wind and solar power) in the US and UK to try to increase production closer to the socially optimal level and deliver a gain in society's welfare.

Alcohol

Alcohol has a negative consumption externality.
Excessive alcohol consumption is linked to crime and antisocial behaviour which the rest of society has to deal with. The consumer doesn't pay the cost that the externality causes leading to the overconsumption of the negative consumption externality.
The MSB < MPB and this creates a welfare loss unless the government intervenes.

Vaccination

Vaccination has positive consumption externalities.
In addition to protecting someone from an illness, vaccination also reduces the risk of that person spreading the illness. As a result, the rest of society is better protected from the illness due to one person's consumption of the vaccine. This is called herd immunity.

1Microeconomics

1.1Competitive Markets: Demand & Suply

1.1.1Markets & Demand

1.1.2Diminishing Marginal Returns

1.1.3Supply

1.1.4Market Equilibrium

1.1.5Price Mechanism

1.1.6Consumer & Producer Surplus

1.1.7IB Multiple Choice - Demand

1.1.8IB Multiple Choice - Supply

1.2Elasticity

1.2.1Elasticities of Demand

1.2.2Factors Affecting Price Elasticity of Demand

1.2.3Elasticity of Supply

1.2.4Price Elasticity of Supply

1.2.5IB Multiple Choice - Price Elasticity of Demand

1.2.6IB Multiple Choice - Price Elasticity of Supply

1.2.7IB Multiple Choice - Other Elasticities

1.3Government Intervention

1.3.1Indirect Taxes & Subsidies

1.3.2Application Question - Taxing Prices or Quantities

1.3.3Subsidies & Price Controls

1.3.4Deadweight Loss & Government Intervention

1.3.5Elasticity & Tax Incidence

1.3.6IB Multiple Choice - Government Intervention

1.4Market Failure

1.4.1Types of Market Failure

1.4.2Introduction to Externalities

1.4.3Negative Externalities

1.4.4Policy for Negative Externalities

1.4.5Positive Externalities

1.4.6The Deadweight Welfare Loss of Externalities

1.4.7Case Study - The Externalities of Education

1.4.8Public Goods & the Free-Rider Problem

1.4.9Asymmetric Information

1.4.10End of Topic Test - Market Failure

1.4.11Application Questions - Market Failure

1.5HL: Theory of the Firm & Market Structures

1.5.1Theory of the Firm & Market Structures

2Macroeconomics

2.1The Level of Overall Economic Activity

2.1.1The Circular Flow of Income

2.1.2Defining GDP

2.1.3Limitations of GDP

2.1.4IB Multiple Choice - Economic Indicators

2.1.5Business Cycles

2.1.6Output Gaps

2.2Aggregate Demand & Aggregate Supply

2.2.1The Aggregate Demand Curve

2.2.2Components of Aggregate Demand

2.2.3Shape of the Aggregate Demand Curve

2.2.4Shifts in Aggregate Demand

2.2.5IB Multiple Choice - Aggregate Demand

2.2.6Short & Long-Run Aggregate Supply

2.2.7Alternative Models of LRAS

2.2.8Equilibrium in the AD-AS Model

2.2.9Output Gaps & the AD-AS Model

2.3Macroeconomic Objectives

2.3.1Introduction to Unemployment

2.3.2Limitations of Unemployment

2.3.3Types of Unemployment

2.3.4Causes & Impact of Unemployment

2.3.5Defining Inflation

2.3.6Measuring Inflation

2.3.7Use of Index Numbers

2.3.8The Consumer Price Index

2.3.9Consequences of Inflation

2.3.10Causes of Inflation

2.3.11Inflation & Unemployment Tradeoff

2.3.12The Short-Run Phillips Curve

2.3.13The Long-Run Phillips Curve

2.4Economic Growth, Poverty & Inequality

2.4.1Measuring Economic Growth

2.4.2Determinants of Productivity

2.4.3Economic Growth & Productivity

2.4.4Absolute & Relative Poverty

2.4.5Inequality

2.4.6Inequality 2

2.4.7Lorenz Curve

2.4.8Government Policy on Poverty

2.4.9End of Topic Test - Poverty & Inequality

2.4.10Application - Inequality & Poverty

2.5Fiscal Policy

2.5.1Introduction to Fiscal Policy

2.5.2Fiscal Policy and AD-AS Model

2.5.3Fiscal Policy Lags

2.5.4Automatic Stabilizers

2.5.5IB Multiple Choice - Fiscal Policy

2.6Monetary Policy

2.6.1Objectives of Monetary Policy

2.6.2Monetary Policy Implementation

2.6.3Monetary Policy & AD-AS Model

2.6.4Monetary Policy Lags & Pitfalls

2.7Supply-Side Policies

2.7.1Supply-Side Policies

2.7.2Supply-Side Policies 2

3The Global Economy

3.1International Trade

3.1.1Globalisation

3.1.2Globalisation for LEDCs

3.1.3Globalisation for MEDCs

3.1.4Comparative Advantage & Trade

3.1.5Protectionism

3.1.6Arguments for Protectionism

3.1.7Arguments Against Protectionism

3.1.8End of Topic Test - Globalisation & Trade

3.1.9Case Study - Globalisation & Trade

3.2Exchange Rates

3.2.1Floating Exchange Rates

3.2.2Fixed Exchange Rate

3.2.3Effect of a Stronger & Weaker Dollar

3.3The Balance of Payments

3.3.1Balance of Payments

3.3.2Balance of Payments 2

3.3.3FDI & Reducing a BoP Deficit

3.4Economic Integration

3.4.1Customs Unions & WTO

3.4.2Merged Currency

3.5Terms of Trade

3.5.1Absolute & Comparative Advantage

3.5.2Gains from Trade

3.5.3Terms of Trade

3.5.4IB Multiple Choice - Comparative Advantage & Trade

3.6Economic Development

3.6.1Factors Influencing Growth & Development

3.6.2International Institutions

3.6.3Measures of Development

3.6.4Barriers to Development

3.6.5Case Study - The Bottom Billion

3.6.6End of Topic Test - Emerging & Developing

3.7The Role of Domestic & International Factors

3.7.1Interventionist Strategies

3.7.2Development Strategies

3.7.3Development Promotion Policies

3.7.4End of Topic Test - Growth & Global Development

3.7.5Application Questions -Growth & Global Development

3.8The Role of International Trade

3.8.1International Institutions

3.8.2End of Topic Test - Globalisation & Trade

3.9The Role of Foreign Aid

3.9.1Aid

3.9.2Limitations of Aid

3.9.3Support for Aid

3.9.4Application Questions - Developing Countries

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