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Econ 001: Midterm 1 Answer Key February 15th, 2011
Instructions:
- This is a 60-minute examination.
- Write all answers in the blue books provided. Show all work. Use diagrams where appropriate and label all diagrams carefully.
- Write your name and your Recitation Instructor's name in every blue book that you use.
- This exam is given under the rules of Penn's Honor system.
- All blue books, blank or filled, must be handed in at the end of this exam. No blue books may be taken from the room.
- No calculators allowed!
The Midterm has 2 parts. Part 1 consists of 8 multiple-choice questions. Part 2 consists of 2 short-answer questions.
You need 2 blue books. You are required to use the two blue books as follows:
- BOOK 1 : write your answers to the 7 multiple-choice questions on the first page and then write your answers to the first short-answer question in the remainder of the book.
- BOOK 2 : write your answers to the second short-answer question.
Part I: Multiple Choice Questions (5 points each/35 points total):
1. Attendance at GREAT meetings on Sundays has fluctuated more this semester than attendance on Mondays. What could explain this?
a. Superbowl Sunday affected the economic cost of attending Sunday sessions but not Monday sessions. b. Proximity of the midterm affected the marginal benefit of attending Monday sessions but not Sunday sessions. c. Both above statements explain attendance patterns listed above. d. Neither statement explains attendance patterns listed above.
2. China and the U.S produce two goods: wild rice and coconut ice cream. The opportunity cost of coconut ice cream (in terms of wild rice) is 2 for the U.S and 4 for china.
Using the information given above, which of the following statement(s) can we definitively say are true?
I. China has an absolute advantage in coconut ice cream production. II. China has a comparative advantage in coconut ice cream production.
a. Both statements. b. Only statement I. c. Only statement II. d. Neither statement.
3. Suppose an economy is currently producing at a point inside the production possibility frontier. We know that
a. the economy lacks the resources to produce at a more desirable point. b. the economy’s available technology prevents it from producing at a more desirable point. c. there may be unemployment in the economy. d. any of the above statements would be a legitimate explanation for the situation.
4. Beans and lentils are substitute goods. Beans are also a normal good. Which of the following statements is wrong?
a. If the price of lentils decreases the demand for beans decreases. b. If the income increases the demand for beans increases. c. If the price of beans increases the demand for lentils increases. d. If the price of lentils increases the demand for lentils decreases.
Answer Key:
**1. a
- d
- c
- d
- b
- c
- a**
Part II: Short Answer Questions (33 points each/61 points total):
Explain answers carefully using graphs where appropriate. Your grade depends on your explanation as well as your answer: so show your work! Keep your answers short! You only need a sentence or two per section.
Q1. Please write your answer in bluebook #1.
Antonia and Elena are two college friends who graduate from Penn Economics in 2009. Now Antonia lives on the island of Maui and owns 10 acres of land. Elena lives on the island of Oahu and owns 10 acres of land as well. Antonia and Elena can produce grapes or peaches with their land. Their productivity, per year, is given in the following table:
Grapes (kilograms per acre )
Peaches (kilograms per acre ) Antonia 1 1 Elena 2 1
a. Draw the joint PPF of Antonia and Elena with grapes on the horizontal axis. If they decide to jointly produce 5 kilograms of peaches, how many kilograms of grapes they can (jointly) produce? Who is producing what? b. Suppose instead of merging into a combined PPF they choose to trade with each other. At what prices of grapes (in terms of peaches) would they agree to trade? Now suppose that the productivity of Antonia changes as following. From the first 6 acres of vines she can produce 1 kilogram grapes per acre. From the 7th acre on, however, each additional acre of vines gives her 0.5 kilograms of grapes. She can still produce 1 kilogram of peaches per acre.
c. Draw the joint PPF of Antonia and Elena in this case.
d. Suppose that Antonia and Elena are producing jointly (as in part c) and that the international price for a kilogram of grapes is 1.5 kilograms of peaches. With this information can you infer what quantities Antonia and Elena will choose to JOINTLY produce? If yes write those quantities if not write an argument of why not.
Answer Key: a. PPF with 1 kink points at (0,20) (20,10) (30,0) 5 kgs peaches will be produced by Antonia. That leaves Antonia producing 5 kgs grapes & Elena 20 kgs grapes for a total of 25 kgs grapes.
Points: PPf with 1 kink: 3 Each points:1 (total3) 25 grapes: Elena grapes: Antonia both:
b. Answer: Price of grapes must be between the two Opportunity Costs or 1/2p<Pg<1p
Points: 6 Price is a range: Each side: Note: if a student suggest one specific (correct) price: 2 points c. Answer: PPf with two kinks with points at (0,20), (20,10), (26,4), (28,0). Points: 7 PPF with 2 kinks: 3 Each point: 1 Note: a PPF with 1 kink gets a max of 3 points. d. Answer: Those with a lower opportunity cost of growing grapes compared to the international price will produce grapes. In this case the first 6 acres of Antonia and the 10 acres of Elena both have an O.C. <1.5 and those acres will grow grapes. The last 4 acres of Antonia have an opportunity cost of 1.5 and they will grow peaches. So we have: 102+61-26 grapes And 41=4 peaches.*
Points: 8 Understanding that we need to compare O.C. to price: Understanding that Elena produces grapes: 1 Understanding that Antonia produces both: 1 26 grapes total: 2 4 peaches: 2
b. Answer: Sean is correct if demand for the games is inelastic. In this case lowering the ticket prices will increase the quantity sold but revenues will decrease. This assumption makes sense if demand is linear as we know that the lower part of the line is inelastic. This would also make sense if we think only die hard 76ers fans would go to watch such a lousy game. They are such good fans they would go anyway, and lowering the price will not attract more spectators.
Points: 6 Relating elasticity to revue: If inelastic and price decrease will decrease rev: Making a meaningful statement about elasticity:
c. Answer: Completely inelastic supply at 20,000. Demand intersects supply at a price higher than 30. The excess demand= (Quantity demanded at P=30)-20,000.
Points: 5 Inelastic supply with higher demand: Equilibrium price above 30: Excess demand: 2
d. Answer: As long as they could still fill all 20,000 seats raising the price is clearly good as Revenues=PQ=P20,000 and is bigger the higher is P. But clearly if they raise the price too much then they may not fill all the seats. In that case too, as long as demand is inelastic, raising the price would increase revenues. Only in the region where demand is elastic would this not make sense.**
Points: 5 If they can sell all seats raising price is clearly good: 3 It makes sense to have empty seats if demand inelastic: 2
e. Answer: As the supply is completely inelastic, as long as the price is set at the equilibrium we know that the entire tax burden will fall of the supplies. Neither Celtic fans not Pistons fans will pay this tax.
Points: 10 Typical graph with tax in the case of completely inelastic supply: 4 Showing tax burden falls of produces: 4 Understanding that it does not depend on demand:
Note: A beautifully drawn graph showing a $5 tax with consumer & producer burdens clearly marked, but with an upward sloping S curve gets 5 points max.
