Negative Externalities

When firms account for external costs of production (in addition to their private costs of production) when making output decisions, this is known as internalizing an externality.

Demand and supply example

This diagram shows the demand and supply for manufacturing refrigerators.

Demand and supply example

The demand curve (D) shows the quantity demanded at each price.
The supply curve (S_private) shows the quantity of refrigerators that all firms in the industry supply at each price assuming they are taking only their private costs into account and they are allowed to emit pollution at zero cost.
Accounting for additional external costs of $100 for every unit produced, the firm’s supply curve will be S_social. The equilibrium will move from E₀ to E₁.

Additional external costs

In this example, we have assumed additional external costs for every refrigerator produced. Why might this be the case?
- As a by-product of the metals, plastics, chemicals and energy that refrigerator manufacturers use, some pollution is created.
- Let’s say that, if these pollutants were emitted into the air and water, they would create costs of $100 per refrigerator produced. These costs might occur because of adverse effects on human health, property values, or wildlife habitat, reduction of recreation possibilities, or because of other negative impacts.
- In a market with no anti-pollution restrictions, firms can dispose of certain wastes absolutely free.

Output decisions

The supply curve is based on choices about production that firms make while looking at their marginal costs, while the demand curve is based on the benefits that individuals perceive while maximizing utility.
If no externalities existed, private costs would be the same as the costs to society as a whole, and private benefits would be the same as the benefits to society as a whole.
Thus, if no externalities existed, the interaction of demand and supply will coordinate social costs and benefits.

Market failure

When the externality of pollution exists, the supply curve no longer represents all social costs. Because externalities represent a case where markets no longer consider all social costs, but only some of them, economists commonly refer to externalities as an example of market failure.
When there is market failure, the private market fails to achieve efficient output, because either firms do not account for all costs incurred in the production of output (negative externality) and/or consumers do not account for all benefits obtained (a positive externality).

Key takeaway

If firms are required to pay the social costs of pollution (and internalize external costs), they would create less pollution but produce less of the product and charge a higher price.

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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