计算线性需求曲线的弹性 Computing the Elasticity of a 需求的收入弹性 Linear Demand curve Income Elasticity of Demand 鉴心滑使衡度大品的需求量对消者 asticity of demand much the quantity demanded of a good responds to a change in consumers'income. ◆用需求量变化的百分数除以收入变化的百分数 It is computed as the percentage change in the quantity demanded divided by the percentage ige in incom 计算收入弹性 收入弹性:物品的类型 Computing Income Elasticity Income Elasticity Types of Goods Percentage Cha ◆正信品 Normal good Income Elasticity ◆劣等品 Inferior Goods ercentage Change 对于正常品来说,更高的收入增加了对 它的需求量;对于劣等品来说,更高的 求的收入弹性= 收入少了对它的需求量 需求量变化的百分数收入变化的百分数 Higher income raises the quantity demanded for normal goods but lowers the quantity demanded for inferior 收入弹性:物品的类型 Income Elasticity 收入弹性的应用 Types of Goods 某物品被消贵看作必需品,它款钡向于黄王收入 ◆随着一国的经济增长和人们收入水平提高,哪 regard as necessities tend to b 种物品的支出额在收入中的比重增加,必需品 income inelastic 还是奢侈品? ●例如食物、常油、衣服、公用事业、图疗服务 Examples include food, fuel clothing, utilities, and medical ◆看侈品 ◆例子:中国,奢侈品成为消费“热点 ◆某些物品被消费者看作奢侈品,它就倾向于喜于此入 ◆80年代:“三大件”—电视、冰箱、洗衣机 oods consumers regard as luxuries tend to be income ◆90年代:空调、汽车、电脑 elastic 例如跑车、毛皮衣服、高档食品 ◆现在:住房、旅游 Examples include sports cars, furs, and expensive foods.6 计算线性需求曲线的弹性 Computing the Elasticity of a Linear Demand Curve Price Quantity Total Revenue (Price x Quantity) Percent Change in Price Percent Change in Quantity Elasticity Description $0 14 $0 200% 15% 0.1 Inelastic 1 12 12 67 18 0.3 Inelastic 2 10 20 40 22 0.6 Inelastic 3 8 24 29 29 1 Unit elastic 4 6 24 22 40 1.8 elastic 5 4 20 18 67 3.7 elastic 6 2 12 15 200 13 elastic 7 0 0 需求的收入弹性 Income Elasticity of Demand ‹ 需求收入弹性衡量一个物品的需求量对消费者 收入变化的反应程度大小。 Income elasticity of demand measures how much the quantity demanded of a good responds to a change in consumers’ income. ‹ 用需求量变化的百分数除以收入变化的百分数 来计算。 It is computed as the percentage change in the quantity demanded divided by the percentage change in income. 计算收入弹性 Computing Income Elasticity Income Elasticity of Demand Percentage Change in Quantity Demanded Percentage Change in Income = 需求的收入弹性＝ 需求量变化的百分数/收入变化的百分数 收入弹性：物品的类型 Income Elasticity - Types of Goods - ‹正常品 Normal Goods ‹劣等品 Inferior Goods ‹对于正常品来说，更高的收入增加了对 它的需求量；对于劣等品来说，更高的 收入减少了对它的需求量 Higher income raises the quantity demanded for normal goods but lowers the quantity demanded for inferior goods. 收入弹性：物品的类型 Income Elasticity - Types of Goods - ‹ 某些物品被消费者看作必需品，它就倾向于缺乏收入 弹性 Goods consumers regard as necessities tend to be income inelastic ‹ 例如食物、燃油、衣服、公用事业、医疗服务 Examples include food, fuel, clothing, utilities, and medical services. ‹ 某些物品被消费者看作奢侈品，它就倾向于富于收入 弹性 Goods consumers regard as luxuries tend to be income elastic. ‹ 例如跑车、毛皮衣服、高档食品 Examples include sports cars, furs, and expensive foods. 收入弹性的应用 ‹ 随着一国的经济增长和人们收入水平提高，哪 种物品的支出额在收入中的比重增加，必需品 还是奢侈品？ ‹ 奢侈品！ ‹ 例子：中国，奢侈品成为消费“热点” ‹80年代：“三大件”——电视、冰箱、洗衣机 ‹90年代：空调、汽车、电脑 ‹现在：住房、旅游