Price elasticity of demand (PED) quantifies how the quantity demanded of a good responds to a change in its price. The formula to calculate the price elasticity of demand is:
Similarly, price elasticity of supply (PES) measures how the quantity supplied responds to a price change. The formula is:
Types of Price Elasticity
Elastic Demand
When the absolute value of the price elasticity of demand is greater than 1, demand is considered elastic. Small changes in price cause significant changes in quantity demanded.
Inelastic Demand
If the absolute value of the price elasticity of demand is less than 1, demand is considered inelastic. Price changes have minimal impact on quantity demanded.
Unitary Elasticity
When the price elasticity of demand is exactly 1, a percentage change in price results in an equal percentage change in quantity demanded.
Perfectly Elastic and Inelastic
- Perfectly Elastic Demand: Infinite responsiveness, depicted by a horizontal demand curve.
- Perfectly Inelastic Demand: Zero responsiveness, depicted by a vertical demand curve.
Historical Context
Origins and Development
The concept of price elasticity was formalized by British economist Alfred Marshall in the late 19th century. His seminal work laid the foundation for modern economic theories of supply and demand.
Evolution in Economic Thought
Over the years, price elasticity has been integrated into various economic models, shaping policy decisions, market strategies, and academic research.
Applicability and Uses
Market Analysis
Businesses use price elasticity to set prices strategically, forecast sales, and determine the potential impact of pricing changes.
Policy Formulation
Governments analyze price elasticity to predict the effects of taxation and subsidies, informing fiscal policies and regulations.
Investment Decisions
Investors look at price elasticity to assess the stability and profitability of various markets, aiding in portfolio management and risk assessment.
Related Terms
- Cross-Price Elasticity: Measures the responsiveness of the quantity demanded for a good to a price change in another good.
$$ \text{Cross-Price Elasticity} = \frac{\%\ \text{change in quantity demanded of Good A}}{\%\ \text{change in price of Good B}} $$
- Income Elasticity of Demand: Examines how the quantity demanded changes in response to a change in income.
$$ \text{Income Elasticity} = \frac{\%\ \text{change in quantity demanded}}{\%\ \text{change in income}} $$
FAQs
Why is price elasticity important?
How is price elasticity calculated?
What factors influence price elasticity?
Can price elasticity be negative?
References
- Marshall, Alfred. “Principles of Economics.” London: Macmillan and Co., 1890.
- Samuelson, Paul A., and Nordhaus, William D. “Economics.” 19th edition. McGraw-Hill Education, 2009.
- Krugman, Paul, and Wells, Robin. “Microeconomics.” 5th edition. Worth Publishers, 2017.
Summary
Price elasticity is a vital concept in understanding market dynamics. By measuring how demand and supply respond to price changes, elasticity provides insight into consumer behavior, informs business strategies, and aids in policy formation. Recognizing its different types and applications can significantly enhance decision-making processes in both economic and financial contexts.
