2. Title: Theory of demand  Subject: Economics  Author: Lai Yuen Ki, Anita  Target audience: Secondary 4 students  How the presentation is to be used: lecture

3. Name: Lai Yuen Ki, Anita Student number: 98059120 Course: EDD 5161F

4. Theory of Demand

5. Quantity demanded  The quantity of a good a person is willing and able to buy at a particular price in a period of time

6. Who eats more? I eat 10 fish a day I eat 10 fish a year

7. Factors affecting quantity demanded Price of the good Future price expectation Price of related goods Others: income, taste Qd

8.  Within a period of time, an increase (decrease) in price of a good results in a decrease (increase) in its quantity demanded, ceteris paribus. The Law of Demand

9. Price Quantity P1 Q1 P2 Q2

10. The Law of Demand Price Quantity P1 Q1 P2 Q2

11. The Law of Demand Price Quantity P1 Q1 P2 Q2

12. The Law of Demand Price Quantity P1 Q1 P2 Q2

13. Ceteris paribus Price of the good Future price expectation Price of related goods Others: income, taste Qd Other factors being constant

14. The Law of Demand Qd Price of the good Ceteris paribus

15. Is change in Qd the same as change in demand?

16. Change in quantity demanded  Caused by a change in a good’s price  Holding all other factors constant  A movement along the same demand curve

17. Change in quantity demanded Price Quantity P1 Q1 P2 Q2

18. Change in quantity demanded Price Quantity P1 Q1 P2 Q2

19. Change in quantity demanded Price Quantity P1 Q1 P2 Q2

20. Change in demand  Caused by a change in factors (e.g. income, taste etc) other than a good’s own price  A shift of the entire demand curve

21. Change in demand Price Quantity P1 Q1 P2 Q2

22. Revision  What is the law of demand?  What is the change in quantity demanded?  What is the change in demand?