1. Supply Macroeconomics Unit 1 Lesson 3 Activities 5 & 6 by
Advanced Placement Economics Teacher Resource Manual. National Council on Economic Education, New York, N.Y.

2. Objectives Define supply schedule and supply curve.
Construct a supply curve using hypothetical data.
Explain why producers are willing to supply more of a good or service when the price increases.
Explain the difference between a shift in the supply curve and a movement along the supply curve.
Explain the difference between an increase in supply and an increase in the quantity supplied.
Describe and analyze the forces that shift the supply curve.
Explain why a supply curve would shift to the right or left given specific changes in the economy.

3. Introduction
This lesson introduces supply, the other half of the market system.
A supply schedule represents the quantities that firms are willing and able to supply at alternative prices.
A supply curve is a graphical representation of the supply schedule.
Remember, understanding a market is essential to success in AP Economics!

4. Introduction
In Activity 5, you will graph a supply schedule, which will help you understand the implications of a shift in the supply curve.
The activity then focuses on the factors that shift the supply curve.
Activity 6 reinforces the factors that cause a supply curve to shift, the direction of the shift and whether the shift represents an increase or decrease in supply.

5. A change in quantity supplied is a change in the quantity of a good that suppliers plan to sell that results from a change in the price of the good.
A change in supply is a change in the quantity that suppliers plan to sell when any influence on selling plans other than the price of the good changes.

6. Movement Along a Supply Curve
As the price declines from P1 to P, the quantity decreases from Q1 to Q
Price decreases, the quantity supplied decreases.

7. Shift in Supply
An increase in supply is a shift to the right( and a decrease in supply is a shift to the left).
Increase in supply from S to S1 shows that at the same price (P), the quantity increased from Q to Q1.

8. Shift in Supply Factors that Shift supply: Number of suppliers
Prices of resources used to produce good
Prices of related goods produced
Technology
Expectations about future prices

9. Activity 5: Supply Curves, Movements Along Supply Curves and Shifts in Supply Curves
Part A
Study the data in Figure 5.1 and plot the supply of Greebes on the axes in Figure 5.2
Label the supply curve S and answer the questions that follow.

10. Activity 5 S

11. The data for supply curve S indicate that at a price of $0
The data for supply curve S indicate that at a price of $0.25 per Greebe, suppliers would be willing to offer ____ million Greebes. Other things constant, if the price of Greebes increased to $0.30 per Greebe, suppliers would be willing to offer ____ million Greebes. Such a change would be an increase in (supply / quantity supplied).
Other things constant, if the price of Greebes decreased to $0.20 per Greebe, suppliers would be willing to offer ____ million Greebes. Such a change would be called a decrease in (supply / quantity supplied).
200
250
150

12. Now, let’s suppose that there is a dramatic change in the price of several of the raw materials used in making Greebes.
This change in the ceteris paribus conditions underlying the original supply of Greebes will result in a new set of data, such as that shown in Figure 5.3.
Study the data, and plot this supply of Greebes on the axes in Figure 5.2.
Label the new supply curve S1 and answer the questions that follow.

13. Activity 5 S1 S

14. 3. Comparing the new supply curve (S1) with the original supply curve (S), we can say that a change in the supply of Greebes results in a shift of the supply curve to the (left / right). Such a shift indicates that at each of the possible prices shown, suppliers are now willing to offer a (smaller / larger) quantity; and at each of the possible quantities shown, suppliers are willing to accept a (higher / lower) minimum price. The cause of this supply curve shift was a(n) (increase / decrease) in prices of several of the raw materials used in making Greebes.

15. 4. Now, let’s suppose that there is a dramatic change in the price of Silopanna, a resource used in the production of Greebes.
This change in the ceteris paribus conditions underlying the original supply of Greebes will result in a new set of data, such as that shown in Figure 5.4.
Study the data, and plot this supply of Greebes on the axes in Figure 5.2.
Label the new supply curve S2 and answer the questions that follow.

16. Activity 5 S1 S S2

17. 4. Comparing the new supply curve (S2) with the original supply curve (S), we can say that a change in the supply of Greebes results in a shift of the supply curve to the (left / right). Such a shift indicates that at each of the possible prices shown, suppliers are now willing to offer a (smaller / larger) quantity; and at each of the possible quantities shown, suppliers are willing to accept a (higher / lower) minimum price. The cause of this supply curve shift was a(n) (increase / decrease) in prices of Silopanna, a resource used in the production of Greebes.

18. Activity 5
Part B
Now, to test your understanding, underline the answer you think is the one best alternative in each of the following multiple-choice questions.

19. Other things constant, which of the following would not cause a change in the long-run supply of beef?
(A) A decrease in the price of beef
(B) A decrease in the price of cattle feed
(C) An increase in the price of cattle feed
(D) An increase in the cost of transporting cattle to market

20. “Falling oil prices have caused a sharp decrease in the supply of oil
“Falling oil prices have caused a sharp decrease in the supply of oil.” Speaking precisely, and using terms as they are defined by economists, choose the statement that best describes this quotation.
(A) The quotation is correct: A decrease in price always causes a decrease in supply.
(B) The quotation is incorrect. A decrease in price always causes an increase in supply, not a decrease in supply.
(C) The quotation is incorrect: A decrease in price causes an increase in the quantity supplied, not a decrease in supply.
(D) The quotation is incorrect. A decrease in price causes a decrease in the quantity supplied, not a decrease in supply.

21. A multiyear drought in Florida has dried the land so that rampant wildfires have destroyed many orange groves. Florida oranges supply much of the nation’s orange juice. Which statement below is correct?
(A) The price of orange juice will rise because of a movement up the supply curve.
(B) The price of orange juice will rise because the supply curve will shift to the left.
(C) The price of orange juice will fall because of a movement down the supply curve.
(D) The price of orange juice will fall because the supply curve will shift to the right.

22. A popular movie star wears a certain style of sunglasses
A popular movie star wears a certain style of sunglasses. If her fans want to copy her look,
(A) the price of the movie star’s brand of sunglasses will rise because of a movement up the supply curve.
(B) the price of the movie star’s brand of sunglasses will rise because the supply curve will shift to the left.
(C) the price of the movie star’s brand of sunglasses will fall because of a movement down the supply curve.
(D) the price of the movie star’s brand of sunglasses will fall because the supply curve will shift to the right.

23. Activity 6: Reasons for Changes in Supply
Part A
Read the eight newspaper headlines in Figure 6.2, and use the table to record the impact, if any, of each event on the supply of cars.
Use the first column to the right of the headline to show whether the event causes a change in supply.
Use the next column to record whether the change is an increase or a decrease in supply.
In the third column, decide whether the supply curve shifts left or right.
Finally, write the letter for the new supply curve.
Use Figure 6.1 to help you.
Always start at curve B, and move only one curve at a time.
Two headlines imply that the supply of cars does not change

24. Activity 6 Y Inc. R C Y Inc. R C Y Dec. L A L Y Dec. A Dec. L A Y Y-- -- -- N -- -- --

25. Part B
Categorize each change in supply in Part A according to the reason why supply changed,
In Figure 6.3, place an X next to the reason that the event described in the headline caused a change in supply.
In some cases, more than one headline could be matched to a reason.
Two headlines do not indicate a shift in supply.

26. X X X X X X X X