微观经济学thebasicsofsupplyanddemand(编辑修改稿)

微观经济学thebasicsofsupplyanddemand(编辑修改稿)内容摘要：

ion, Inc. Chapter 2 44 Other Demand Elasticities Ine Elasticity of Demand Measures how much quantity demanded changes with a change in ine III / IQ / Q E I 169。 2020 Pearson Education, Inc. Chapter 2 45 Other Demand Elasticities CrossPrice Elasticity of Demand Measures the percentage change in the quantity demanded of one good that results from a one percent change in the price of another good mbbmmmbbPQ PPPPEmb 169。 2020 Pearson Education, Inc. Chapter 2 46 Other Demand Elasticities Complements: Cars and Tires Crossprice elasticity of demand is negative  Price of cars increases, quantity demanded of tires decreases Substitutes: Butter and Margarine Crossprice elasticity of demand is positive  Price of butter increases, quantity of margarine demanded increases 169。 2020 Pearson Education, Inc. Chapter 2 47 Price Elasticity of Supply Measures the sensitivity of quantity supplied given a change in price Measures the percentage change in quantity supplied resulting from a 1 percent change in price PQE SSP%%169。 2020 Pearson Education, Inc. Chapter 2 48 Point vs. Arc Elasticities Point elasticity of demand Price elasticity of demand at a particular point on the demand curve Arc elasticity of demand Price elasticity of demand calculated over a range of prices   QPPQE DP ΔΔ169。 2020 Pearson Education, Inc. Chapter 2 49 Elasticity: An Application During the 1980’s and 1990’s, the market for wheat went through changes that had great implications for American farmers and US agricultural policy Using the supply and demand curves for wheat, we can analyze what occurred in this market 169。 2020 Pearson Education, Inc. Chapter 2 50 Elasticity: An Application Supply: QS = 1900 + 24P Demand: QD = 3550 – 266P 169。 2020 Pearson Education, Inc. Chapter 2 51 Elasticity: An Application QD = QS 1800 + 240P = 3550 – 266P 506P = 1750 P = $ per bushel Q = 1800 + (240)() = 2630 million bushels 169。 2020 Pearson Education, Inc. Chapter 2 52 Elasticity: An Application We can find the elasticities of demand and supply at these points 0 35.)(6 30,2ΔΔ PPE DDP032.)(630,2ΔΔ PPE SSP169。 2020 Pearson Education, Inc. Chapter 2 53 Elasticity: An Application Assume the price of wheat is $4 8 6,2))(2 6 6(5 5 0,3 DQ)2 6 6(4 8 6,2 DPQ169。 2020 Pearson Education, Inc. Chapter 2 54 Elasticity: An Application In 2020, the supply and demand for wheat were: Supply: QS = 1439 + 267P Demand: QD = 2809 – 226P 169。 2020 Pearson Education, Inc. Chapter 2 55 Elasticity: An Application QD = QS 2809 226P = 1439 + 267P P = $ per bushel Q = 2809 (226)() = 2181 million bushels Price of wheat fell in nominal terms. 169。 2020 Pearson Education, Inc. Chapter 2 56 ShortRun Versus LongRun Elasticity Price elasticity varies with the amount of time consumers have to respond to a price Shortrun demand and supply curves often look very different from their longrun counterparts 169。 2020 Pearson Education, Inc. Chapter 2 57 ShortRun Versus LongRun Elasticity Demand In general, demand is much more price elastic in the long run  Consumers take time to adjust consumption habits  Demand might be linked to another good that changes slowly  More substitutes are usually available in the long run 169。 2020 Pearson Education, Inc. Chapter 2 58 Gasoline: ShortRun and LongRun Demand Curves DSR DLR • People cannot easily adjust consumption in the short run. • In the long run, people tend to drive smaller and more fuel efficient cars. Quantity of Gas Price 169。 2020 Pearson Education, Inc. Chapter 2 59 ShortRun Versus LongRun Elasticity Demand and Durability For some durable goods, demand is more elastic in the short run If goods are durable, then when price increases, consumers choose to hold on to the good instead of replacing it But in long run, older durable goods will have to be replaced 169。 2020 Pearson Education, Inc. Chapter 2 60 DSR DLR • Initially, people may put off immediate car purchase • In long run, older cars must be replaced Cars: ShortRun and LongRun Demand Curves Quantity of Cars Price 169。 2020 Pearson Education, Inc. Chapter 2 61 ShortRun Versus LongRun Elasticity Ine elasticity also varies with the amount of time consumers have to respond to an ine change For most goods and services, ine elasticity is larger in the long run When ine changes, it takes time to adjust spending 169。 2020 Pearson Education, Inc. Chapter 2 62 ShortRun Versus LongRun Elasticity Ine elasticity of durable goods Ine elasticity is less in the long run than in the short run  Increases in ine mean consumers will want to hold more cars  Once older cars are replaced, purchases will only be to replace old cars  Less purchases from ine increase in long run than in short run 169。 2020 Pearson Education, Inc. Chapter 2 63 Demand for Gasoline 169。 2020 Pearson Education, Inc. Chapter 2 64 Demand for Automobiles 169。 2020 Pearson Education, Inc. Chapter 2 65 ShortRun Versus LongRun Elasticity Most goods and services: Longrun price elasticity of supply is greater than shortrun price elasticity of supply Other Goods (durables, recyclables): Longrun price elasticity of supply is less than shortrun price elasticity of supply 169。 2020 Pearson Education, Inc. Chapter 2 66 SSR Quantity Primary Copper Price ShortRun Versus LongRun Elasticity SLR Due to limited capacity, firms are limited by output constraints in the short run. In the long run, they can expand. 169。 2020 Pearson Education, Inc. Chapter 2 67 SSR Qua。