(Answered) Define and explain price elasticity of demand and give some references.Define and explain price…

Definition
Price elasticity of demand (PED) measures the responsiveness of the quantity demanded of a good or service to a change in its price. It is calculated as the percentage change in quantity demanded divided by the percentage change in price.
Formulae
Common formulas:
PED = (% change in quantity demanded) / (% change in price)
Point elasticity (using calculus): PED = (dQ/dP) × (P/Q)
Arc elasticity (between two points): PED = [(Q2 − Q1) / ((Q1 + Q2)/2)] ÷ [(P2 − P1) / ((P1 + P2)/2)]
Interpretation
|PED| > 1: demand is elastic (quantity responds more than proportionally to price changes).
|PED| < 1: demand is inelastic (quantity responds less than proportionally). |PED| = 1: unit elastic (proportional response). PED is usually negative due to the inverse relationship between price and quantity demanded; absolute value is often reported. Determinants of Price Elasticity Availability of close substitutes (more substitutes → more elastic). Proportion of income spent on the good (larger share → more elastic). Necessity vs. luxury (necessities tend to be more inelastic). Time horizon (demand generally more elastic in the long run). Definition of the market (narrowly defined markets typically more elastic). Examples - A 10% price increase for a product with PED = −2 would reduce quantity demanded by approximately 20%. - Essentials like basic food staples often have inelastic demand, while non-essential luxury goods or specific brand items often have elastic demand. Practical notes Firms use PED to set prices so as to maximize revenue or profit; for example, when demand is elastic, a price cut can increase total revenue. Policymakers use elasticity to predict effects of taxes, subsidies, or price controls on consumption and tax revenues. References N. Gregory Mankiw, "Principles of Economics" — standard undergraduate textbook covering elasticity concepts. Robert S. Pindyck and Daniel L. Rubinfeld, "Microeconomics" — detailed treatment of demand and elasticity measures. Investopedia — "Price Elasticity of Demand (PED)": https://www.investopedia.com/terms/p/priceelasticity.asp Khan Academy — elasticity lessons and worked examples: https://www.khanacademy.org/economics-finance-domain/microeconomics/elasticity-topic Wikipedia — "Price elasticity of demand": https://en.wikipedia.org/wiki/Price_elasticity_of_demand