Multiple Choice

Question Form A Form B Form C Form D Form E
1 B D B D C
2 D B D A B
3 A D D B D
4 D B B C D
5 D A C C D
6 A B D D A
7 C D C C A
8 D A A D B
9 B D A D B
10 B A A A A
11 A C B D A
12 C D D B B
13 C C B B A
14 A C A B B
15 A A B B C
16 D A C A D
17 A B B A D
18 B B A B C
19 B A A A B
20 B B D A A

Problem 21

This problem is the same on all forms.

Part A: The quantity changes by 150,000 - 200,000 = -50,000. The average quantity is (200,000+150,000)/2 = 175,000. Thus quantity changes by (-50,000/175,000) = -28.57%. Price changes by $1. The average price is (1+2)/2 = 1.5. Thus price changes by 1/1.5 = 66.67%. Finally, the elasticity is the per cent change in quantity divided by the per cent change in price. So the absolute elasticity e = .2857/.6667 = 0.429. (More precisely, e = 3/7.)

Part B: The elasticity in part A is less than 1, so demand is inelastic.

Problem 22

This problem is the same on all forms.

Solution Diagram

Part A: Without Excise Tax

Supply and demand intersect at E, corresponding to a price of $6 per lb. and quantity of 6 million pounds.

Part B: With Excise Tax

There are two ways to solve this. One is to incorporate the excise tax by shifting the supply curve up by the tax of $2. The new equilibrium is at E', corresponding to a (buyer's) price of $8. After paying the $2 tax, the seller receives an after-tax price of $6. The equilibrium quantity is 4 million pounds.

The second method is to use a tax wedge—look for a quantity where the demand price is $2 higher than the supply price. Since the supply price is always $6, we look for a demand price of $8. That occurs at E', with the same result as before.