文档介绍：Elasticity of demand and supply Elasticity Price elasticity of demand Introduction Market supply and demand Quantity Price O Q1 P1 a S1 D Quantity Price O Q2 Q1 P1 P2 b S2 S1 D a Market supply and demand Quantity Price O Q2 Q1 P1 P2 S2 S1 D D' a b Market supply and demand Quantity Price O Q3 Q2 Q1 P1 P2 P3 c S2 S1 D D' a b Market supply and demand Elasticity Measuring price elasticity of demand The mid-point (arc) method Price elasticity of demand Proportionate (or %) DQD Proportionate (or %) DP ÷ DQD QD DP P ÷ DQD mid QD DP mid P P (£) Q (000s) Demand m n Measuring elasticity using the arc method P (£) Q (000s) DQ DP mid Q mid P ¸ Ped = Demand m n Q = 10 P = –2 Mid P 7 Mid Q 15 Measuring elasticity using the arc method