In: Economics
Table 11-3
This table describes the defense demands for three equal sized
groups of people in Nirvanaville. The second, third, and fourth
column shows the quantity that a group will demand for a given
price (the first column).
Price |
Group #1 |
Group #2 |
Group #3 |
$14 |
0 |
0 |
0 |
$12 |
0 |
0 |
3 |
$10 |
0 |
3 |
6 |
$ 8 |
3 |
6 |
13 |
$ 6 |
6 |
13 |
22 |
$ 4 |
13 |
22 |
33 |
$ 2 |
22 |
33 |
44 |
$ 0 |
33 |
44 |
58 |
Refer to Table 11-3. If the marginal cost of
national defense is constant at $12 per unit, what is the efficient
level of national defense to provide?
Group of answer choices
3 units
13 units
22 units
33 units
National defence is a public good.
The market demand of a public good is vertical summation of individual's demand.
Vertical summation means summing up the price each individual is will to pay for a unit of good.
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For 3 units, group #1 is willing to $8, group #2 is willing to pay $10 and group #3 is willing to pay $12.
The Market price for 3 units = $8 + $10 + $12 = $30
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For 6 units, group #1 is willing to $6, group #2 is willing to pay $8 and group #3 is willing to pay $10.
The Market price for 6 units = $6 + $8 + $10 = $24
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For 13 units, group #1 is willing to $4, group #2 is willing to pay $6 and group #3 is willing to pay $8.
The Market price for 13 units = $4 + $6 + $8 = $18
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For 22 units, group #1 is willing to $2, group #2 is willing to pay $4 and group #3 is willing to pay $6.
The Market price for 22 units = $2 + $4 + $6 = $12
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For 33 units, group #1 is willing to $0, group #2 is willing to pay $2 and group #3 is willing to pay $4.
The Market price for 33 units = $0 + $2 + $4 = $6
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Market demand for a national defence (Public good)
Quantity | Market price |
3 | 30 |
6 | 24 |
13 | 18 |
22 | 12 |
33 | 6 |
Optimal number of public good occurs at the point where market price and marginal cost are equal.
Market price = Marginal cost = 12 corresponding to 22 units of national defence.
Therefore, efficient level of national defence to provide is 22 units
Answer: Option (C)