1. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 1 Managerial Economics in a Global Economy, 5th Edition by Dominick Salvatore Chapter 3 Demand Theory

2. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 2 Law of Demand There is an inverse relationship between the price of a good and the quantity of the good demanded per time period. Substitution Effect Income Effect

3. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 3 Individual Consumer’s Demand Qd X = f(P X, I, P Y, T) quantity demanded of commodity X by an individual per time period price per unit of commodity X consumer’s income price of related (substitute or complementary) commodity tastes of the consumer Qd X = P X = I = P Y = T =

4. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 4 Qd X = f(P X, I, P Y, T)  Qd X /  P X < 0  Qd X /  I > 0 if a good is normal  Qd X /  I < 0 if a good is inferior  Qd X /  P Y > 0 if X and Y are substitutes  Qd X /  P Y < 0 if X and Y are complements

5. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 5 Market Demand Curve Horizontal summation of demand curves of individual consumers Bandwagon Effect Snob Effect

6. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 6 Horizontal Summation: From Individual to Market Demand

7. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 7 Market Demand Function QD X = f(P X, N, I, P Y, T) quantity demanded of commodity X price per unit of commodity X number of consumers on the market consumer income price of related (substitute or complementary) commodity consumer tastes QD X = P X = N = I = P Y = T =

8. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 8 Demand Faced by a Firm Market Structure –Monopoly –Oligopoly –Monopolistic Competition –Perfect Competition Type of Good –Durable Goods –Nondurable Goods –Producers’ Goods - Derived Demand

9. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 9 Linear Demand Function Q X = a 0 + a 1 P X + a 2 N + a 3 I + a 4 P Y + a 5 T PXPX QXQX Intercept: a 0 + a 2 N + a 3 I + a 4 P Y + a 5 T Slope:  Q X /  P X = a 1

10. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 10 Price Elasticity of Demand Linear Function Point Definition

11. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 11 Price Elasticity of Demand Arc Definition

12. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 12 Marginal Revenue and Price Elasticity of Demand

13. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 13 Marginal Revenue and Price Elasticity of Demand PXPX QXQX MR X

14. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 14 Marginal Revenue, Total Revenue, and Price Elasticity TR QXQX MR<0MR>0 MR=0

15. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 15 Determinants of Price Elasticity of Demand Demand for a commodity will be more elastic if: It has many close substitutes It is narrowly defined More time is available to adjust to a price change

16. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 16 Determinants of Price Elasticity of Demand Demand for a commodity will be less elastic if: It has few substitutes It is broadly defined Less time is available to adjust to a price change

17. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 17 Income Elasticity of Demand Linear Function Point Definition

18. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 18 Income Elasticity of Demand Arc Definition Normal GoodInferior Good

19. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 19 Cross-Price Elasticity of Demand Linear Function Point Definition

20. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 20 Cross-Price Elasticity of Demand Arc Definition SubstitutesComplements

21. Prepared by Robert F. Brooker, Ph.D. Copyright ©2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide 21 Other Factors Related to Demand Theory International Convergence of Tastes –Globalization of Markets –Influence of International Preferences on Market Demand Growth of Electronic Commerce –Cost of Sales –Supply Chains and Logistics –Customer Relationship Management