第7章消费者、生产者与市场效率

(b) Price = $70
Price of Album $100 John ’s consumer surplus ($30) 80 70 Total consumer surplus ($40)
Paul ’s consumer surplus ($10)
50
Demand 0 1 2 3 4 Quantity of Albums
Four Possible Buyers’ Willingness to Pay
The Demand Schedule and the Demand Curve
Price of Album $100 John ’s willingness to pay Paul ’ s willingness to pay George ’s willingness to pay
A 0 Q1 Q2 Quantity
市场效率
消费者剩余= 卖者的评价-买者支付的量 生产者剩余= 卖者得到的量-卖者的成本 总剩余=卖者的评价-买者支付的量+卖者得 到的量-卖者的成本
总剩余=买者的评价-卖者的成本
效率：资源配置使社会所有成员得到的总 剩余最大化的性质。 平等：福利在社会成员中分配的公平性。
(b) Consumer Surplus at Price P
Price
A
Initial consumer surplus
P1
C
B
Consumer surplus to new consumers
P2
F D E Additional consumer surplus to initial consumers Q1 Q2 Demand
第7章 消费者、生产者与市场效率
要点： 消费者剩余 生产者剩余 供给与需求均衡使市场总剩余最大
福利经济学：研究资源配置如何影响经济 福利。 市场上供求均衡可以使买者与卖者得到的 总利益最大化！
实证研究&规范研究
消费者剩余
支付意愿：买者愿意为某种物品支付的最 高量。 消费者剩余：买者的支付意愿减买者的实 际支付量。
The Costs of Four Possible Sellers
The Supply Schedule and the Supply Curve
The Supply Schedule and the Supply Curve
Measuring Producer Surplus with the Supply Curve (a) Price = $600
Value to buyers is less than cost to sellers.
(b) Producer Surplus at Price P Price Additional producer surplus to initial producers D E F Supply
P2
P1
B
Initial producer surplus C Producer surplus to new producers
0
Quantity
消费者剩余，即买者愿意为一种物品支付 的量减他们实际支付的量，衡量了消费者 从一种物品中得到的买者自己感觉到的利 益。
在大多数市场上，消费者剩余反映了经济 福利。
生产者剩余
成本：卖者为了生产一种物品必须放弃的 每种东西的价值。 生产者剩余：卖者出售一种物品得到的量 减卖者的成本。
Quantity
自由市场把物品的供给分配给对这些物品 评价最高的买者，这种评价由他们的支付 意愿来表示。 自由市场把物品的需求分配给可以以最低 成本生产这些物品的卖者。 自由市场生产使消费者和生产者剩余总和 最大化的产量。
The Efficiency of the Equilibrium Quantity
Price of House Painting
Supply
$900
800 600
500
Grandma’ s producer surpห้องสมุดไป่ตู้us ($100)
0
1
2
3
4 Quantity of Houses Painted
Measuring Producer Surplus with the Supply Curve (b) Price = $800
需求曲线以下和价格以上的面积衡量市场 的消费者剩余。
How the Price Affects Consumer Surplus
(a) Consumer Surplus at Price P Price A
Consumer surplus P1 B C
Demand
0
Q1
Quantity
How the Price Affects Consumer Surplus
How the Price Affects Producer Surplus
(a) Producer Surplus at Price P Price Supply
P1
B Producer surplus C
A
0 Q1 Quantity
How the Price Affects Producer Surplus
Price Supply
Value to buyers
Cost to sellers
Cost to sellers 0 Equilibrium quantity
Value to buyers is greater than cost to sellers.
Value to buyers
Demand
Quantity
80 70
50
Ringo ’s willingness to pay
Demand
0
1
2
3
4
Quantity of Albums
(a) Price = $80
Price of Album $100 John ’s consumer surplus ($20)
80
70
50
Demand
0
1
2
3
4
Quantity of Albums
Consumer and Producer Surplus in the Market Equilibrium
Price A D
Supply
Consumer surplus Equilibrium price Producer surplus
E
B
C 0 Equilibrium quantity
Demand
Price of House Painting
Supply Total producer surplus ($500)
$900
800 600
500
Georgia ’s producer surplus ($200)
Grandma’s producer surplus ($300)
0
1
2
3
4 Quantity of Houses Painted