Download 經濟學原理第一次作業解答

經濟學原理第 4 次作業解答
選擇題:
1.A 2.D 3.B 4.B 5.D 6.A 7.D 8.B 9.C 10.A 11.D 12.C
13.C 14.B 15.C
問答題：
CH5
PROBLEMS 6
b.
c.
CH6
6. a.
Ann’s consumer surplus is $2,250. Arthur’s consumer surplus is $500, and
Abby’s consumer surplus is $250.
Consumer surplus is the area under the demand curve above the market price. At $20, Ann
will travel 300 miles, Arthur will travel 200 miles, and Abby will travel 100 miles. To find
Ann’s consumer surplus extend her demand schedule until you find the price at which the
quantity demanded by Ann is zero—the price at which Ann’s demand curve cuts the
y-axis. This price is $35 a passenger mile. So Ann’s consumer surplus equals (35 20)/2
multiplied by 300, which equals $2,250. Similarly, Arthur’s consumer surplus equals (25 
20)/2 multiplied by 200, which equals $500. And Abby’s consumer surplus equals (25 
20)/2 multiplied by 100, which equals $250.
Ann’s consumer surplus is the largest because she places a higher value on each unit of the
good than the other two do.
Ann’s consumer surplus rises by $1,750. Arthur’s consumer surplus rises by $1,500, and
Abby’s consumer surplus rises by $750.
At $15 a mile, Ann travels 400 miles and her consumer surplus is $4,000. Ann’s consumer
surplus equals (35  15)/2 multiplied by 400, which equals $4,000. Ann’s consumer
surplus increases from $2,250 to $4,000, an increase of $1,750. Arthur travels 400 miles
and his consumer surplus is $2,000, an increase of $1,500. Abby travels 200 miles and her
consumer surplus is $1,000, an increase of $750.
PROBLEMS 2
2.a.
b.
c.
d.
Equilibrium price is $450 a month and the equilibrium quantity is 20,000 housing units.
The quantity rented is 10,000 housing units.
The quantity of housing rented is equal to the quantity supplied at the rent ceiling.
The shortage of housing is 20,000 housing units.
At the rent ceiling, the quantity of housing demanded is 30,000, but the quantity supplied
is 10,000, so there is a shortage of 20,000 housing units.
The maximum price that someone is willing to pay for the 10,000th unit available is $600
a month.
The demand curve tells us the maximum price that someone is willing to pay for the
10,000th unit.
CH6
PROBLEMS 6
6.a.
b.
With no tax on roses, the price is $14 a bunch and 80 bunches a week are bought.
The price is $18 a bunch, and 60 bunches a week are bought. Buyers pay $4 of the tax on a
bunch of roses and sellers pay $2 of the tax on roses.
The tax decreases the supply of roses and raises the price of a bunch of roses. With no tax,
producers are willing to sell 80 bunches a week for $14 a bunch. But with a $6 a bunch
tax, they are willing to sell 80 bunches a week only if the price is $6 a bunch higher at $20
a bunch. That is, the price at which producers are willing to sell 40 bunches a week when
the tax is $6 a bunch is $16 a bunch; the price at which producers are willing to sell 60
bunches a week when the tax is $6 a bunch is $18 a bunch.
At $18 a bunch, the quantity demanded is 60 bunches a week. $18 a bunch is the price
when the tax is $6 a bunch at which they are willing to sell 60 bunches a week. So the
quantity sold is 60 bunches a week. The price has risen from $14 a bunch to $18 a bunch,
so buyers pay $4 of the $6 tax. Sellers pay the other $2 of tax.