西方经济学第一次作业
1?假设大学里篮球票的价格是由市场力量决定的。现在，需求与供给表如下:
价格（美元）需求量（张）供给量（张） 4 10000 80009 8 8000 8000 12 6000 8000 16 4000 8000
20 2000 8000
a. 画出需求曲线和供给曲线。这条供给曲线有什么不寻常之处？为什么会 是这样的？
b. 篮球票的均衡价格和均衡数量是多少？
c. 明年你们大学计划共增加 5000名学生。增加的学生的需求表如下： 价格（美元） 需求量（张） 4 4000 8
3000
12 2000 16 1000 20 0
现在把原来的需求表与新生的需求表加在一起计算整个大学的新需求表。 的均衡价格和均衡数量是多少？
a.
新
As Figure 2-25 shows, the supply curve is vertical. The constant supply makes sense because
the basketball arena has a fixed number of seats no matter what the price.
Quantity of Basketball Tickets
Figure 2-25
b.
Quan tity supplied equals qua ntity dema nded at a price of $8. The equilibrium quantity is 8,000 tickets.
c.
Price $ 4「 8 12 16
Quantity Demanded 14,000 11,000 8,000 5,000 2,000 Quantity Supplied 8,000 8,000 8,000 8,000 8,000 20 The new equilibrium price will be $12, which equates quantity demanded to quantity supplied.
The equilibrium quantity is 8,000 tickets.
2. 假设公务乘客和度假乘客对从纽约到波士顿之间民航机票的需求如下: 价格 需求量
（美元）（公务乘客）
需求量
（度假乘客）
150 2100 1000
200 2000 800 250 1900 600 300 1800 400 a ?当票价从200美元上升到250美元时，公务乘客的需求价格弹性为多少? 度假乘客的需求价格弹性为多少？（用中点法计算。）
b ?为什么度假乘客与公务乘客的需求价格弹性不同？ a.
For bus in ess travelers, the price elasticity of dema nd whe n the price of tickets
rises from
$200 to $250 is [(2,000 - 1,900)/1,950]/[(250 - 200)/225] = 3/13 = 0.23. For vacatio ners, the price elasticity of dema nd whe n the price of tickets rises from $200 to $250 is [(800 - 600)/700] / [(250 - 200)/225] = 9/7 = 1.29.
b.
The price elasticity of dema nd for vacati oners is higher tha n the elasticity for bus in ess travelers because vacati oners can more easily choose a differe nt mode of tran sportati on (like drivi ng or tak ing the trai n). Busin ess travelers are less
likely to do so since time is more important to them and their schedules are less adaptable.
3. 这是一个热天，Bert 口干舌燥。下面是他对一瓶水的评价:
对第一瓶水的评价 7 美元 对第二瓶水的评价 5 美元 对第三瓶水的评价 3 美元
对第四瓶水的评价 1 a.美元 根据以上信息推导出 Bert的需求表。画出他对瓶装水的需求曲线
b.如果一瓶水的价格是 4美元，Bert会买多少瓶水? Bert从他的购买中得
到了多少消费者剩余？在你的图形中标出 Bert的消费者剩余。
c .如果价格下降到2美元，需求量会有何变化？ Bert的消费者剩余会有何 变化？用你的图形说明这些变化
a.
Bert 's dema nd schedule i
Price More than $7 $5 to $7 $3 to $5 $1 to $3
Quantity Demanded 0 1 2 3 4 $1 or less Bert 's dema nd curve is show n in Figure 9.
$7 ------- 6 -
5 - A -------- 4 --------------------
3 - B
2 -----------
12 3 4
Quantity of Water
Figure 9
b.
Whe n the price of a bottle of water is $4, Bert buys two bottles of water.His
consumer surplus is shown as area A in the figure. He values his first bottle of water at $7, but pays only $4 for it, so has con sumer surplus of $3. He values his sec ond bottle of water at $5, but pays only $4 for it, so has con sumer surplus of $1. Thus Bert 'otalt con sumer surplus is $3 + $1 = $4, which is the area of A in the figure.
c. When the price of a bottle of water falls from $4 to $2, Bert buys three bottles of water, an in crease of one. His con sumer surplus con sists of both areas A and B in the figure, an in crease in the amount of area B. He gets con sumer surplus of $5 from the first bottle ($7 value mi nus $2 price), $3 from the seco nd bottle ($5 value minus $2 price), and $1 from the third bottle ($3 value minus $2 price), for a total con sumer surplus of $9. Thus con sumer surplus rises by $5 (which is the size of area B) when the price of a bottle of water falls from $4 to $2.
4、假设技术进步使生产电脑的成本降低了。
a?用供求图说明电脑市场上价格、数量、消费者剩余和生产者剩余会发生什 么变动。
b?电脑和加法机是替代品。用供求图说明加法机市场上的价格、数量、消费 者剩余和生产者剩余会发生什么变动。电脑技术进步对加法机生产者而言是有幸 还是不幸？ c.电脑和软件是互补品。用供求图说明软件市场上的价格、数量、消费者剩 余和生产者剩余会发生什么变动。电脑技术进步对软件生产者而言是有幸还是不 幸?
a.
The effect of falli ng product ion costs in the market for computers results in a shift
to the right in the supply curve, as shown in Figure 14. As a result, the equilibrium price of computers decli nes and the equilibrium qua ntity in creases.
The decli ne
in the price of computers in creases con sumer surplus from area A to A + B + C + D, an in crease in the amount B + C + D.
Figure 14
Prior to the shift in supply, producer surplus was areas B + E (the area above the supply curve and below the price). After the shift in supply, producer surplus is areas E + F + G. So producer surplus cha nges by the amount F + G -B, which
经济学基础第一次作业09答案
