This document discusses the concepts of price elasticity of demand and supply. It begins by introducing price elasticity and how it measures the responsiveness of quantity demanded or supplied to changes in price. It then provides formulas for calculating the price elasticity coefficient and discusses what values indicate elastic versus inelastic demand. The document also examines graphical analysis of elasticity and how it varies along a demand curve. It analyzes applications of elasticity concepts and discusses determinants of a good's price elasticity. Finally, it briefly introduces other types of elasticity like cross elasticity of demand and income elasticity of demand.