PHAN TICH CAU VA HANH VI CA NHAN

BÀI PHÂN TÍCH CẦU VÀ HÀNH VI CÁ NHÂN NHĨM Phạm Thị Nhân Ngơ Quang Việt Huỳnh Văn Nguyễn Tấn Lộc GVHD: PGS, TS, NGUYỄN VĂN NGÃI TÀI LIỆU THAM KHẢO MICHAEL R BAYE (1994) MANAGERIAL ECONOMICS AND BUSINESS STRATEGY Publisher: McGraw-Hill Irwin, pp.73-154 + Chương 3: Phân tích cầu McGraw-Hill/Irwin Michael R Baye, Managerial Economics and Business Strategy Copyright © 2008 by the McGraw-Hill Companies, Inc All rights reserved + TỔNG QUAN I Độ co giãn  Độ co giãn giá  Độ co giãn tỏng doanh thu  Độ co giãn chéo cầu the giá  Độ co giãn theo thu nhập II Chức cầu tuyến tính 3-3 + 3-4 ĐỘ CO GIÃN  Biến đổi biến số “G” so với biến số “S” EG , S %G  %S Nếu EG,S > 0, S G có liên quan trực tiếp nha Nếu EG,S < 0, S G có liên quan ngược Nếu EG,S = 0, S G khơng có liên quan + 3-5 ĐỘ CO GIÃN CỦA CẦU EQX , PX  %QX  %PX d Luật nhu cầu Co giãn (Elastic): EQX , PX  Kém co giãn (Inelastic): EQ X , PX  Co giãn đơn vị (Unitary): EQX , PX 1 + 3-6 CÁC TRƯỜNG HỢP ĐẶC BIỆT Giá Giá D Cầu co giãn hoàn tồn Cầu khơng co giãn D Lượng Perfectly Elastic ( EQ X ,PX  ) Lượng Perfectly Inelastic ( EQX , PX 0) 3-7 + ĐỘ CO GIÃN VÀ TỔNG DOANH THU  Elastic   Inelastic   Increase (a decrease) in price leads to a decrease (an increase) in total revenue Increase (a decrease) in price leads to an increase (a decrease) in total revenue Unitary  Total revenue is maximized at the point where demand is unitary elastic + 3-8 Elasticity, Total Revenue and Linear Demand P 100 TR 10 20 30 40 50 Q Q + 3-9 Elasticity, Total Revenue and Linear Demand P 100 TR 80 800 10 20 30 40 50 Q 10 20 30 40 50 Q + 3-10 Elasticity, Total Revenue and Linear Demand P 100 TR 80 1200 60 800 10 20 30 40 50 Q 10 20 30 40 50 Q 4-27 More Is Better!  More  Is Better Property Bundles that have at least as much of every good and more of some good are preferred to other bundles  Bundle B is preferred to A since B contains at least as much of good Y and strictly more of good X  Bundle B is also preferred to C since B contains at least as much of good X and strictly more of good Y  More generally, all bundles on ICIII are preferred to bundles on ICII or ICI And all bundles on ICII are preferred to ICI Good Y III II I 100 A B C 33.33 Good X Diminishing Marginal Rate of Substitution  Marginal Rate of Substitution      The amount of good Y the consumer is willing to give up to maintain the same satisfaction level decreases as more of good X is acquired The rate at which a consumer is willing to substitute one good for another and maintain the same satisfaction level To go from consumption bundle A to B the consumer must give up 50 units of Y to get one additional unit of X To go from consumption bundle B to C the consumer must give up 16.67 units of Y to get one additional unit of X To go from consumption bundle C to D the consumer must give up only 8.33 units of Y to get one additional unit of X 4-28 Good Y III II I A 100 B 50 C 33.33 25 D Good X 4-29 Consistent Bundle Orderings  Transitivity Property   Good Y For the three bundles A, B, and C, the transitivity III property implies that if C  B II and B  A, then C  A I Transitive preferences along with the more-is-better property imply that  indifference curves will not intersect  the consumer will not get caught in a perpetual cycle of indecision A 100 C 75 B 50 Good X 4-30 The Budget Constraint  Opportunity Set  The set of consumption bundles that are affordable  PxX  + PyY  M Budget Line  The Opportunity Set Budget Line M/PY Y = M/PY – (PX/PY)X The bundles of goods that exhaust a consumers income  PxX + PyY = M  Market Rate of Substitution  Y The slope of the budget line  -Px / Py M/PX X 4-31 Changes in the Budget Line Y  Changes   Increases lead to a parallel, outward shift in the budget M0/PY line (M1 > M0) Decreases lead to a parallel, M2/PY downward shift (M2 < M0)  Changes   in Income M1/PY in Price A decreases in the price of Y good X rotates the budget line counter-clockwise (PX0 > M0/PY PX1) M2/PX M0/PX M1/PX X New Budget Line for a price decrease An increases rotates the budget line clockwise (not shown) M0/PX0 M0/PX1 X 4-32 Consumer Equilibrium  The equilibrium consumption bundle is the affordable bundle that yields the highest level of satisfaction   Consumer equilibrium occurs at a point where MRS = PX / PY Equivalently, the slope of the indifference curve equals the budget line Y M/PY Consumer Equilibrium III II I M/PX X + 4-33 Price Changes and Consumer Equilibrium  Substitute Goods  An increase (decrease) in the price of good X leads to an increase (decrease) in the consumption of good Y  Examples:  Coke and Pepsi  Verizon Wireless or AT&T  Complementary Goods  An increase (decrease) in the price of good X leads to a decrease (increase) in the consumption of good Y  Examples:  DVD and DVD players  Computer CPUs and monitors + 4-34 Complementary Goods When the price of Pretzels (Y) good X falls and the consumption of Y rises, then X and Y M/PY are complementary goods (PX1 > PX2) B Y2 II A Y1 I X1 M/PX1 X2 M/PX2 Beer (X) + Income Changes and Consumer Equilibrium  Normal Goods   Good X is a normal good if an increase (decrease) in income leads to an increase (decrease) in its consumption Inferior Goods  Good X is an inferior good if an increase (decrease) in income leads to a decrease (increase) in its consumption 4-35 + 4-36 Normal Goods An increase in income increases the consumption of normal goods Y M1/Y (M0 < M1) B Y1 M0/Y II A Y0 I X0 M0/X X1 M1/X X + 4-37 Decomposing the Income and Substitution Effects Initially, bundle A is consumed A decrease in the price of good X expands the consumer’s opportunity set Y C The substitution effect (SE) causes the consumer to move from bundle A to B A II A higher “real income” allows the consumer to achieve a higher indifference curve The movement from bundle B to C represents the income effect (IE) The new equilibrium is achieved at point C B I IE SE X + 4-38 A Classic Marketing Application Other goods (Y) A buy-one, get-one free pizza deal A C E D II I 0.5 B F Pizza (X) 4-39 Individual Demand Curve Y  An individual’s demand curve is derived from each new equilibrium point found on the indifference curve as the price of good X is varied II I $ X P0 P1 D X0 X1 X 4-40 Market Demand  The market demand curve is the horizontal summation of individual demand curves  It indicates the total quantity all consumers would purchase at each price point $ 50 Individual Demand Curves $ Market Demand Curve 40 D1 D2 Q DM Q + 4-41 Conclusion  Indifference curve properties reveal information about consumers’ preferences between bundles of goods     Completeness More is better Diminishing marginal rate of substitution Transitivity  Indifference curves along with price changes determine individuals’ demand curves  Market demand is the horizontal summation of individuals’ demands ... trường 4-22 + Consumer Behavior  Consumer Opportunities   Consumer Preferences   The possible goods and services consumer can afford to consume The goods and services consumers actually consume... HÀNH VI NGƯỜI TIÊU DÙNG McGraw-Hill/Irwin Michael R Baye, Managerial Economics and Business Strategy Copyright © 2008 by the McGraw-Hill Companies, Inc All rights reserved + TỔNG QUAN I Hành vi. .. Better  Diminishing Marginal Rate of Substitution  Transitivity 4-26 Complete Preferences  Completeness Property  Consumer is capable of expressing preferences (or indifference) between all