1.1.3
Supply
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The Supply Curve
The supply curve shows the relationship between price (on the vertical axis) and quantity (shown on the horizontal axis).

Incentive to expand production
- When a firm's profits increase, it is incentivised to produce more output. This is because the more it produces, the more profit it will earn.
- So, when costs of production fall, a firm will be incentivised to supply a higher quantity at a given price.
- This is shown by a rightward shift in the supply curve.
- Subsidies can lower a firms average cost per unit, encouraging them to expand production also.

Causes of supply curve shifts
- Changes in the price of inputs (these will affect the cost of production).
- A discovery of a new technology (allowing the firm to produce at a lower cost).
- Changes in Government policy.
- E.g taxes, regulations and subsidies.

Effect of tax on supply
- The U.S. government imposes a tax on alcoholic drinks that collects eight billion dollars per year from producers.
- Taxes are treated as a cost by businesses.
- Higher costs decrease supply.
- So taxes decrease supply.
Factors Determining the Supply of Goods and Services
There are several factors that affect the supply of goods and services in an economy, including the price of a good.

Price of the good
- A rise in price will almost always lead to an increase in the quantity supplied of that good or service. This is also called an extension in supply.
- This is because the increase in price incentivises the firm to increase output.
- Economists call this positive relationship 'the law of supply'.

Technology and production
- A reduction in the costs of production will lead to an increase in supply because producer profits have risen.
- Technological improvements can increase the efficiency of the productive process.
- This will reduce the costs of production, shifting supply to the right.

Productivity and tax
- Increases in productivity means the output per input of a factor of supply increases, so supply shifts right.
- An indirect tax on supply raises the overall cost of production, shifting supply left.
1Microeconomics
1.1Competitive Markets: Demand & Suply
1.2Elasticity
1.3Government Intervention
1.4Market Failure
1.4.1Types of Market Failure1.4.2Introduction to Externalities1.4.3Negative Externalities1.4.4Policy for Negative Externalities1.4.5Positive Externalities1.4.6The Deadweight Welfare Loss of Externalities1.4.7Case Study - The Externalities of Education1.4.8Public Goods & the Free-Rider Problem1.4.9Asymmetric Information1.4.10End of Topic Test - Market Failure1.4.11Application Questions - Market Failure
1.5HL: Theory of the Firm & Market Structures
2Macroeconomics
2.1The Level of Overall Economic Activity
2.2Aggregate Demand & Aggregate Supply
2.2.1The Aggregate Demand Curve2.2.2Components of Aggregate Demand2.2.3Shape of the Aggregate Demand Curve2.2.4Shifts in Aggregate Demand2.2.5IB Multiple Choice - Aggregate Demand2.2.6Short & Long-Run Aggregate Supply2.2.7Alternative Models of LRAS2.2.8Equilibrium in the AD-AS Model2.2.9Output Gaps & the AD-AS Model
2.3Macroeconomic Objectives
2.3.1Introduction to Unemployment2.3.2Limitations of Unemployment2.3.3Types of Unemployment2.3.4Causes & Impact of Unemployment2.3.5Defining Inflation2.3.6Measuring Inflation2.3.7Use of Index Numbers2.3.8The Consumer Price Index2.3.9Consequences of Inflation2.3.10Causes of Inflation2.3.11Inflation & Unemployment Tradeoff2.3.12The Short-Run Phillips Curve2.3.13The Long-Run Phillips Curve
2.4Economic Growth, Poverty & Inequality
2.5Fiscal Policy
2.6Monetary Policy
2.7Supply-Side Policies
3The Global Economy
3.1International Trade
3.2Exchange Rates
3.3The Balance of Payments
3.4Economic Integration
3.5Terms of Trade
3.6Economic Development
3.7The Role of Domestic & International Factors
3.8The Role of International Trade
3.9The Role of Foreign Aid
Jump to other topics
1Microeconomics
1.1Competitive Markets: Demand & Suply
1.2Elasticity
1.3Government Intervention
1.4Market Failure
1.4.1Types of Market Failure1.4.2Introduction to Externalities1.4.3Negative Externalities1.4.4Policy for Negative Externalities1.4.5Positive Externalities1.4.6The Deadweight Welfare Loss of Externalities1.4.7Case Study - The Externalities of Education1.4.8Public Goods & the Free-Rider Problem1.4.9Asymmetric Information1.4.10End of Topic Test - Market Failure1.4.11Application Questions - Market Failure
1.5HL: Theory of the Firm & Market Structures
2Macroeconomics
2.1The Level of Overall Economic Activity
2.2Aggregate Demand & Aggregate Supply
2.2.1The Aggregate Demand Curve2.2.2Components of Aggregate Demand2.2.3Shape of the Aggregate Demand Curve2.2.4Shifts in Aggregate Demand2.2.5IB Multiple Choice - Aggregate Demand2.2.6Short & Long-Run Aggregate Supply2.2.7Alternative Models of LRAS2.2.8Equilibrium in the AD-AS Model2.2.9Output Gaps & the AD-AS Model
2.3Macroeconomic Objectives
2.3.1Introduction to Unemployment2.3.2Limitations of Unemployment2.3.3Types of Unemployment2.3.4Causes & Impact of Unemployment2.3.5Defining Inflation2.3.6Measuring Inflation2.3.7Use of Index Numbers2.3.8The Consumer Price Index2.3.9Consequences of Inflation2.3.10Causes of Inflation2.3.11Inflation & Unemployment Tradeoff2.3.12The Short-Run Phillips Curve2.3.13The Long-Run Phillips Curve
2.4Economic Growth, Poverty & Inequality
2.5Fiscal Policy
2.6Monetary Policy
2.7Supply-Side Policies
3The Global Economy
3.1International Trade
3.2Exchange Rates
3.3The Balance of Payments
3.4Economic Integration
3.5Terms of Trade
3.6Economic Development
3.7The Role of Domestic & International Factors
3.8The Role of International Trade
3.9The Role of Foreign Aid
Practice questions on Supply
Can you answer these? Test yourself with free interactive practice on Seneca — used by over 10 million students.
- 1
- 2What does a supply curve show?Multiple choice
- 3What is happening to supply in this diagram?Multiple choice
- 4
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