4.3 Indifferent Curve and decision making on Consumption 无差异曲线与消费决策
无差异曲线与消费决策 4.3 Indifferent Curve and Decisionmaking on Consumption
教学目标Ob pectives ■理解无差异曲线、消费可能线的含义 ■了解无差异曲线的特征 掌握消费可能线的数学表达式 学会运用图形分析消费者均衡 知识点 Knowledge 无差异曲线及其特征 消费可能线 无差异曲线分析消费者均衡条件 技能点Skil 学会运用图形分析消费者均衡
教学目标Objectives： ▪ 理解无差异曲线、消费可能线的含义 ▪ 了解无差异曲线的特征 ▪ 掌握消费可能线的数学表达式 ▪ 学会运用图形分析消费者均衡 知识点Knowledge： 无差异曲线及其特征 消费可能线 无差异曲线分析消费者均衡条件 技能点Skills： 学会运用图形分析消费者均衡
专业词汇 Professional terms Indifferent Curve Decision-making on Consumption marginal utility theory consumer choice indifferent analysis Indifferent set satisfaction Possibility line of consumption budget line isocost line Risk
Indifferent Curve Decision-making on Consumption marginal utility theory consumer choice indifferent analysis Indifferent set satisfaction Possibility line of consumption budget line isocost line Risk 专业词汇Professional terms
Even though the multi-commodity version of marginal utility theory is useful in demonstrating the underlying logic of consumer choice. it still has a major weakness Utility cannot be measured in any absolute sense. We cannot really say, therefore, by how much the marginal utility of one good exceeds another An alternative approach is to use indifferent analysis This does not involve measuring the amount of utility a person gains, but merely ranking various combinations of goods in order of preference. In other words, it assumes that consumers can decide whether they prefer one combination of goods to another
Even though the multi-commodity version of marginal utility theory is useful in demonstrating the underlying logic of consumer choice, it still has a major weakness. Utility cannot be measured in any absolute sense. We cannot really say, therefore, by how much the marginal utility of one good exceeds another. An alternative approach is to use indifferent analysis. This does not involve measuring the amount of utility a person gains, but merely ranking various combinations of goods in order of preference. In other words, it assumes that consumers can decide whether they prefer one combination of goods to another
无差异曲线 (一)什么是无差异曲线 iNdifferent curve a line showing all those combinations of two goods between which a consumer is indifferent, i. e. those combinations that give the same level of satisfaction or utility -Indifferent set a table showing the same information as an indifferent curve
一、无差异曲线 （一）什么是无差异曲线 ▪Indifferent curve A line showing all those combinations of two goods between which a consumer is indifferent: i.e. those combinations that give the same level of satisfaction or utility. ▪Indifferent set A table showing the same information as an indifferent curve
无差异曲线 (一)什么是无差异曲线 无差异曲线是用来表示两种商品的不同数量的组 合给消费者带来的效用完全相同的一条曲线。也 称等效用曲线。 假定现有Ⅹ与Y两种商品的组合方式如表42所 示,各种组合方式能给消费者带来相同的效用, 可以做出一条无差异曲线。无差异曲线一般用字 母U表示
一、无差异曲线 （一）什么是无差异曲线 ▪无差异曲线是用来表示两种商品的不同数量的组 合给消费者带来的效用完全相同的一条曲线。也 称等效用曲线。 ▪假定现有Ｘ与Ｙ两种商品的组合方式如表4-2所 示，各种组合方式能给消费者带来相同的效用， 可以做出一条无差异曲线。无差异曲线一般用字 母U表示
无差异曲线 (一)什么是无差异曲线 两种商品消费数量组合示意表 组合方式 X商品 Y商品 30 ABCDEF 10 18 15 13 20 10 5 30
一、无差异曲线 （一）什么是无差异曲线 两种商品消费数量组合示意表 组合方式 X商品 Y商品 A 5 30 B 10 18 C 15 13 D 20 10 E 25 8 F 30 7
无差异曲线 (二)无差异曲线的特征 无差异曲线是一条向右下方倾斜,凸向原点,斜率为负 值的曲线 同一个平面图上可以有无数条无差异曲线,并且离原点 越远代表的效用水平越高 在同一平面图上,任意两条无差异曲线不能相交
一、无差异曲线 （二）无差异曲线的特征 ▪无差异曲线是一条向右下方倾斜，凸向原点，斜率为负 值的曲线 ▪同一个平面图上可以有无数条无差异曲线，并且离原点 越远代表的效用水平越高 ▪在同一平面图上，任意两条无差异曲线不能相交
无差异曲线 (二)无差异曲线的特征 图4-2两种商品消费量组合无差异曲线图 30 25 B 20 5050 10 20 30 40 X商品消费数量
一、无差异曲线 （二）无差异曲线的特征 图4-2 两种商品消费量组合无差异曲线图 0 5 10 15 20 25 30 35 0 10 20 30 40 X商品消费数量 Y商品消费数量 U A B C D E F
无差异曲线 (二)无差异曲线的特征 边际替代率是消费者在消费两种商品保持效用 不变时,减少一种商品的消费量与增加的另一种 商品的消费量之比 MRsTX=Mx/MU=-Y/△X
一、无差异曲线 （二）无差异曲线的特征 边际替代率是消费者在消费两种商品保持效用 不变时，减少一种商品的消费量与增加的另一种 商品的消费量之比。 MRSTXY = MUX / MUY = −Y /X