1.3 Incomes and Cross elasticity of Demand 需求收入弹性与需求交叉弹性
需求收入弹性与需求交叉弹性 1.3 Incomes and Cross Elasticity of Demand
教学目标 Objectives: 理解需求收入弹性、交叉弹性的含义 ■了解需求收入弹性的种类 掌握恩格尔定律的基本內容 ■明确需求收入弹性在社会经济生活中的应用 ■学会运用需求交叉弹性理论 知识点 Knowledge 需求收入弹性、需求交叉弹性 恩格尔定律 技能点Si: 需求收入弹性的运用 需求交叉弹性的运用
教学目标Objectives： ▪ 理解需求收入弹性、交叉弹性的含义 ▪ 了解需求收入弹性的种类 ▪ 掌握恩格尔定律的基本内容 ▪ 明确需求收入弹性在社会经济生活中的应用 ▪ 学会运用需求交叉弹性理论 知识点Knowledge： ▪ 需求收入弹性、需求交叉弹性 ▪ 恩格尔定律 技能点Skills： ▪ 需求收入弹性的运用 ▪ 需求交叉弹性的运用
专业词汇 Professional terms Income elasticity of demand Cross elasticity of demand international trade balance of payments
Income elasticity of demand Cross elasticity of demand international trade balance of payments 专业词汇Professional terms
、需求收入弹性 (一)什么是需求收入弹性 (Income elasticity of demand) Income elasticity The responsiveness of demand to a change in consumer income The major determinant of income elasticity of demand is the degree of 'necessityof the goods. 需求收入弹性被用来表示消费者对某种商品需求量 的变动对收入变动的反应程度
（一）什么是需求收入弹性 (Income elasticity of demand) Income elasticity The responsiveness of demand to a change in consumer income. The major determinant of income elasticity of demand is the degree of ‘necessity’ of the goods. 需求收入弹性被用来表示消费者对某种商品需求量 的变动对收入变动的反应程度。 一、需求收入弹性
、需求收入弹性 (二)需求收入弹性的种类 Normal goods goods whose demand increases as consumer income increase. They have a positive income elasticity of demand. Luxury goods will have a higher income elasticity of demand than more basic goods 正常品( ormal good 劣等品( inferior good)
（二）需求收入弹性的种类 ▪ Normal goods Goods whose demand increases as consumer income increase. They have a positive income elasticity of demand. Luxury goods will have a higher income elasticity of demand than more basic goods. ▪ 正常品 (normal good) ▪ 劣等品 (inferior good) 一、需求收入弹性
、需求收入弹性 (三)恩格尔定理 随着收入的提高,食物支出在全部收入中所 占的比率越来越小,也就是食物支出占全 部收入的比率中随着消费者收入水平的提 髙而递减。这一定理就称为恩格尔定理
（三）恩格尔定理 随着收入的提高，食物支出在全部收入中所 占的比率越来越小，也就是食物支出占全 部收入的比率中随着消费者收入水平的提 高而递减。这一定理就称为恩格尔定理。 一、需求收入弹性
、需求收入弹性 (四)商品需求收入弹性理论的应用 a Income elasticity of demand is an important concept to firms considering the future size of the market for their product. If the product has a high income elasticity of demand. sales are likely to expand rapidly as national income rises but may also fall significantly if the economy moves into recession
（四）商品需求收入弹性理论的应用 ▪ Income elasticity of demand is an important concept to firms considering the future size of the market for their product. If the product has a high income elasticity of demand, sales are likely to expand rapidly as national income rises, but may also fall significantly if the economy moves into recession. 一、需求收入弹性
、需求收入弹性 第一,利用需求收入弹性可以分析国民经济各部门, 各地区的收入现状,便于制订合理的收入政策。 第二,利用收入弹性来协调国民经济各种商品发展 的合理比例。 第三,利用需求收入弹性原理确定合理的出口商品 结构
▪ 第一，利用需求收入弹性可以分析国民经济各部门， 各地区的收入现状，便于制订合理的收入政策。 ▪ 第二，利用收入弹性来协调国民经济各种商品发展 的合理比例。 ▪ 第三，利用需求收入弹性原理确定合理的出口商品 结构。 一、需求收入弹性
二、需求交叉弹性 (Cross elasticity of demand) a Cross-price elasticity of demand The responsiveness of demand for one good to a change in the price of another(either a substitute or a complementary) aIt enables us to predict how much the demand curve for the first product will shift when the price of the second product changes The major determinant of cross elasticity of demand is the closeness of the substitute or complement. The closer it is, the bigger will be the effect on the first good of a change in the price of the substitute or complement, and hence the greater the cross elasticity either positive or negative
三、单个需求与市场需求 二、需求交叉弹性 (Cross elasticity of demand) ▪Cross-price elasticity of demand The responsiveness of demand for one good to a change in the price of another (either a substitute or a complementary). ▪It enables us to predict how much the demand curve for the first product will shift when the price of the second product changes. ▪The major determinant of cross elasticity of demand is the closeness of the substitute or complement. The closer it is, the bigger will be the effect on the first good of a change in the price of the substitute or complement, and hence the greater the cross elasticity – either positive or negative
二、需求交叉弹性 (Cross elasticity of demand) ˉ需求交叉弹性是需求交叉价格弹性( Cross-price elasticity of demand)的简称,它表示一种商品的需求量 变动对另一种商品价格变动的反应程度 互补商品之间:Exy0
三、单个需求与市场需求 二、需求交叉弹性 (Cross elasticity of demand) ▪需 求 交 叉 弹 性 是 需 求 交 叉 价 格 弹 性 (Cross-price elasticity of demand)的简称，它表示一种商品的需求量 变动对另一种商品价格变动的反应程度。 ▪互补商品之间：Ｅxy＜0。 ▪替代商品之间：Ｅxy＞0