消费者选择理论教学讲义

Quantity of Pepsi
500 B
Consumer’s bud0
Quantity
of Pizza
消费者的预算约束 The Consumer’s Budget Constraint
可选择的是，消费者在50个比萨饼 和250品脱百事可乐之间取舍。 Alternately, the consumer can buy 50 pizzas and 250 pints of Pepsi.
预算线上任意一点表示消费者在两种商品中的 消费组合或权衡。
Any point on the budget constraint line indicates the consumer’s combination or tradeoff between two goods. 例如，假如消费不买比萨饼，他能买500品脱 百事可乐（B点）。假如他不买百事可乐，它 能买100个比萨饼(A点)。
The consumer is indifferent, or equally happy, with the combinations shown at points A, B, and C because they are all on the same curve.
预算约束 The Budget Constraint
预算约束线表示消费者支付得起得消 费组合。
The budget constraint depicts the consumption “bundles” that a consumer can afford.
人们消费的之所以比他们想要的少是因为他 们受到收入的约束或限制。
预算线的斜率等于两种物品的相对价格，也就 是说，一种物品与另一种物品相比的价格。 The slope of the budget constraint line equals the relative price of the two goods, that is, the price of one good compared to the price of the other. 消费者的预算约束线的斜率衡量消费者可以用 一种物品换到另一种物品的比率。
消费者的预算约束 The Consumer’s Budget Constraint
Quantity of Pepsi
500 B
250
C
Consumer’s budget constraint
A
0
50
100
Quantity
of Pizza
消费者的预算约束 The Consumer’s Budget Constraint
消费者选择理论 The Theory of Consumer Choice
第21章 Chapter 21
消费者选择理论可以解决以下问题 The theory of consumer choice addresses the following questions:
所有需求曲线都向右下方倾斜吗？ Do all demand curves slope downward? 工资如何影响劳动供给？ How do wages affect labor supply? 利率如何影响家庭储蓄？ How do interest rates affect household saving? 穷人更偏好于现金还是实物转移支付？ Do the poor prefer to receive cash or in-kind transfers?
用无差异曲线代表偏好
Representing Preferences with Indifference Curves
无差异曲线显示了使消费者同 样满足的消费组合。 An indifference curve shows bundles of goods that make the consumer equally happy.
It measures the rate at which the consumer will trade one good for the other.
偏好，消费者的购买欲望
Preferences: What the Consumer Wants
消费者在不同消费束的偏好可以用无差 异曲线表示。 A consumer’s preference among consumption bundles may be illustrated with indifference curves.
消费者偏好 The Consumer’s Preferences...
Quantity of Pepsi
C
B
D
I2
A
无差异曲线I1
0
Quantity
of Pizza
消费者偏好 The Consumer’s Preferences
消费者在A、B、C三点的消费组合是无 差异的，因为他们在同一条曲线上。
For example, if the consumer buys no pizzas, he can afford 500 pints of Pepsi (point B). If he buys no Pepsi, he can afford 100 pizzas (point A).
消费者的预算约束 The Consumer’s Budget Constraint
It shows the various combinations of goods the consumer can afford given his or her income and the prices of the two goods.
消费者的预算约束
The Consumer’s Budget Constraint
People consume less than they desire because their spending is constrained, or limited, by their income.
预算约束
The Budget Constraint
它表明的是，在既定的收入和两种商品 的价格情况下，消费者能够提供的不同 商品消费组合。