Is the price of oranges a substitute for apples increases what will happen to the demand for apples?

Practice Problems -- Demand 

ANSWERS - These answers are only explanations of how you should have drawn your graphs. 

You need to draw the graphs to get full credit.

Graphically show what will happen in each case (to demand or quantity demanded).  Remember to always assume ceteris paribus unless otherwise noted. Make sure you label your axes correctly !!

1. Assume peanut butter and jelly are complements.  What will happen to the demand or quantity demanded for jelly if the price of peanut butter increases?

Answer:  The demand curve for jelly will shift to the left (decrease).  Since you would buy less peanut  butter when its price increases, you will also buy less jelly (since they are complements).

2. Assume that Jello is a normal good.  What will happen to the demand or quantity demanded of Jello if the income of the people who buy Jello goes down?

Answer:  The demand curve for Jello will shift to the left (decrease).  By definition, a normal good is a good we buy less of if income goes down. 

3.  Assume that turkey and ham are substitutes.  What will happen to the demand or quantity demanded for ham if the price of turkey increases?

Answer:  The demand curve for ham will shift to the right (increase).  Since the price of turkey has gone up, some people will shift out of turkey and into ham.

4.  Assume the price of cars increases.  What will happen to the quantity demanded of cars?

Answer:  There is no shift in the demand curve for cars.  You would put two different prices and quantities along your curve and show why demand would decrease along the horizontal (quantity) axis.

5.   Assume Spam is an inferior good.  What will happen to the demand or quantity demanded of Spam if the income of the people buying Spam decreases?

Answer:  The demand curve for Spam will shift to the right (increase).  By definition an inferior good is one we buy more of if our income goes down.

6.  Assume popcorn and movies are complements.  What will happen to the demand or quantity demanded for popcorn if the price of movies goes down?

Answer:  The demand curve for popcorn will shift to the right (increase).  Since you would go to more movies if the price of movies goes down, you would also buy more popcorn (since they are complements).

7.  Assume that bread and butter are complements.  Also assume that bread is a normal good.  What will happen to the demand or quantity demanded for bread if the price of butter increases AND the income of the people who buy bread increases?  (Hint: shift one at a time but on the same graph).

Answer:  The demand curve for bread will shift to the left (decrease) due to the price of butter increasing (we will buy less butter and therefore also less bread since they are complements) and then there will be another shift in the demand curve for bread (on the same graph) - it will shift to the right (since buy definition a normal good is a good we buy more of if our income goes up).  So you will shift the curve to the left and to the right -- SHOW both shifts on your graph.

8.  Assume that apples are an inferior good.  Also assume that apples and oranges are substitutes, and that apples and caramel are complements.  What will happen to the demand or quantity demanded for apples if the price of oranges decreases AND the income of the people who buy apples increases AND the price of caramel increases?  (Hint: shift one at a time but on the same graph).

Answer:  The demand curve for apples will first shift tot he left (due to the price of oranges dropping - so some people will buy more oranges and fewer apples) and then the demand curve for apples will shift to the left again (since income increased and apples are an inferior good) and the demand curve for apples will shift left a third time (since we will buy less caramel and therefore fewer apples - since they are complements).  Show ALL THREE SHIFTS TO THE LEFT with three single arrows.

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  • Is the price of oranges a substitute for apples increases what will happen to the demand for apples?
    Figure 7.3 Utility Maximization and an Individual’s Demand Curve Mary Andrews’s demand curve for apples, d, can be derived by determining the quantities of apples she will buy at each price. Those quantities are determined by the application of the marginal decision rule to utility maximization. At a price of $2 per pound, Ms. Andrews maximizes utility by purchasing 5 pounds of apples per month. When the price of apples falls to $1 per pound, the quantity of apples at which she maximizes utility increases to 12 pounds per month.

    Is the price of oranges a substitute for apples increases what will happen to the demand for apples?
    Figure 7.5 Deriving a Market Demand Curve The demand schedules for Mary Andrews, Ellen Smith, and Koy Keino are given in the table. Their individual demand curves are plotted in Panel (a). The market demand curve for all three is shown in Panel (b).

    Is the price of oranges a substitute for apples increases what will happen to the demand for apples?
    Figure 7.6 The Substitution and Income Effects of a Price Change This demand curve for Ms. Andrews was presented in Figure 7.5. It shows that a reduction in the price of apples from $2 to $1 per pound increases the quantity Ms. Andrews demands from 5 pounds of apples to 12. This graph shows that this change consists of a substitution effect and an income effect. The substitution effect increases the quantity demanded by 4 pounds, the income effect by 3, for a total increase in quantity demanded of 7 pounds.

      Is the price of oranges a substitute for apples increases what will happen to the demand for apples?
      Figure 7.7 Substitution and Income Effects for Inferior Goods The substitution and income effects work against each other in the case of inferior goods. The consumer begins at point A, consuming q1 units of the good at a price P1. When the price falls to P2, the consumer moves to point B, increasing quantity demanded to q2. The substitution effect increases quantity demanded to qs, but the income effect reduces it from qs to q2.

        Is the price of oranges a substitute for apples increases what will happen to the demand for apples?
        Figure 7.8: Charles Haynes – rice – CC BY-SA 2.0.

        Sources: Robert Jensen and Nolan Miller, “Giffen Behavior: Theory and Evidence,” KSG Faculty Research Working Papers Series RWP02-014, 2002 available at ksghome.harvard.edu/~nmiller/giffen.html or http://ssrn.com/abstract=310863. At the authors’ request we include the following note on the preliminary version: “Because we have received numerous requests for this paper, we are making this early draft available. The results presented in this version, while strongly suggestive of Giffen behavior, are preliminary. In the near future we expect to acquire additional data that will allow us to revise our estimation technique. In particular, monthly temperature, precipitation, and other weather data will enable us to use an instrumental variables approach to address the possibility that the observed variation in prices is not exogenous. Once available, the instrumental variables results will be incorporated into future versions of the paper.” ; David McKenzie, “Are Tortillas a Giffen Good in Mexico?” Economics Bulletin 15:1 (2002): 1–7.

        When the price of oranges a substitute for apples falls What happens to the demand for apples?

        Considering that the two are substitute goods, you would purchase the cheaper one. That is why the demand for apple increases.

        How will an increase in the price of apples affect the market for oranges?

        For example, if apples and oranges are substitutes for a consumer, then if the price of apples increases, the consumer will buy less of apples and more of oranges. Thus, when price of apples increases, the demand for oranges will rise.

        Is the price of oranges increases the demand for apple juice will?

        Orange juice and Apple juice are substitute goods and if price of one increase then demand for another also increase. Was this answer helpful?

        What happens to demand when substitute price increases?

        The demand for a good increases, if the price of one of its substitutes rises. The demand for a good decreases, if the price of one of its substitutes falls.