bài giảng micro

TRƯỜNG ĐẠI HỌC CƠNG NGHIỆP TP.HỒ CHÍ MINH KHOA QUẢN TRỊ KINH DOANH TRẦN NGUYỄN MINH ÁI BÀI GIẢNG MICROECONOMICS Lưu hành nội Tháng 09 – 2008 MICROECONOMICS TRẦN NGUYỄN MINH ÁI INTRODUCTION • CONTENTS • • • • • • • Chapter 01: The Foundation Of Economics Chapter 02: Supply ang Demand Chapter 03: Consumer behavior Chapter 04: Producer behavior Chapter 05: Perfect competition Chapter 06: Monopoly Chapter 07: Oligopoly and Monopolistic Competition Economy THE FOUNDATION OF ECONOMICS The word economy comes from a Greek word for “one who manages a household.” Microeconomics TEN PRINCIPLES OF ECONOMICS • A household and an economy face many decisions: • Who will work? • What goods and how many of them should be produced? • What resources should be used in production? • At what price should the goods be sold? THE FOUNDATION OF ECONOMICS SOCIETY HAS VIRTUALLY UNLIMITED WANTS BUT LIMITED OR SCARCE PRODUCTIVE RESOURCES! -2- TEN PRINCIPLES OF ECONOMICS Society and Scarce Resources: • The management of society’s resources is important because resources are scarce • Scarcity means that society has limited resources and therefore cannot produce all the goods and services people wish to have Scarcity • Scarcity — the imbalance between our desires and available resources—forces us to make economic choices Microeconomics -3- GOODS & SERVICES PROVIDE SCARCE RESOURCES UTILITY LUXURIES vs NECESSITIES LAND CAPITAL LABOR Also known as the Input Factors of Production ENTREPRENEURIAL ABILITY Basic Economic Questions Scarcity Choices must be made What To Produce? How To Produce? For Whom To Produce? PRODUCTION POSSIBILITIES A Consumer Good PIZ ZA for example Microeconomics -4- PRODUCTION POSSIBILITIES A Capital Good PRODUCTION POSSIBILITIES What if we could only produce 10,000 Robots or 400,000 Pizzas Ro bo ts Using all of our resources, to get some pizza, we must give up some robots! for example PRODUCTION POSSIBILITIES PIZZA (in hundred thousands) ROBOTS 10 Robots (thousands) (in thousands) Pizzas (hundred thousands) Production Possibilities • Production possibilities are the alternative combination of final goods and services that could be produced in a given period of time with all available resources and technology PRODUCTION POSSIBILITIES Limited Resources means a limited output At any point in time, a full-employment, fullproduction economy must sacrifice some of product X to obtain more of product Y -5- PRODUCTION POSSIBILITIES Q 14 Robots (thousands) Microeconomics 13 12 11 10 Unattainable A B C W Attainable & Efficient D Attainable but Inefficient E Pizzas (hundred thousands) Opportunity Costs • Opportunity cost is the most desired goods or services that are forgone in order to obtain something else • It is what is given up in order to get something else Q Principle #1: People Face Tradeoffs “There is no such thing as a free lunch!” Microeconomics PRINCIPLES OF ECONOMICS Economics is the study of how society manages its scarce resources -6- Scarcity and Economics • The scarcity of resources—and the choices it forces us to make—is the source of all of the problems studied in economics • Households allocate limited income among goods and services • Business firms choices of what to produce and how much are limited by costs of production • Government agencies work with limited budgets and must carefully choose which goals to pursue • Economists study these decisions to • Explain how our economic system works • Forecast the future of our economy • Suggest ways to make that future even better Microeconomics • Micro • Micro comes from Greek word mikros, meaning “small” • Microeconomics • Study of behavior of individual households, firms, and governments • Choices they make • Interaction in specific markets • Focuses on individual parts of an economy, rather than the whole Macroeconomics • Macro • Macro comes from Greek word, makros, meaning “large” • Macroeconomics • Study of the economy as a whole • Focuses on big picture and ignores fine details Microeconomics -7- Positive Economics • Study of how economy works • Statements about how the economy works are positive statements • Accuracy of positive statements can be tested by looking at the facts—and just the facts Normative Economics • Study of what should be • Used to make value judgments, identify problems, and prescribe solutions • Statements that suggest what we should about economic facts, are normative statements • Based on values • Normative statements cannot be proved or disproved by the facts alone Unlimited Needs and Wants Scarce Productive Resources Relative Scarcity Basic Economic Questions The Need for an Economic System Types of Economic Systems • The Market economy • The Command economy • The Mixed economy Microeconomics Types of Economic Systems • The Market economy • The Command economy • The Mixed economy Government Intervention and Command Economies • Karl Marx argued that the government not only had to intervene but had to own all the means of production • Markets permit capitalists to enrich themselves while the proletariat toil long hours for subsistence wages -8- The Invisible Hand of a Market Economy • The market mechanism is the use of market prices and sales to signal desired outputs (or resource allocations) • The market decides the mix of output in an economy A Mixed Economy • A mixed economy is one that uses both market signals and government directives to allocate goods and resources • Most economies use a combination of market signals and government directives to select economic outcomes Microeconomics -9- MARKETS DEFINED CHAPTER Markets: Demand & Supply DEMAND DEFINED DEMAND SCHEDULE P $5 QD 10 20 35 55 80 Various Amounts A Series of Possible Price …a specified time period …ceteris paribus BUYERS SELLERS MARKETS Demand in Output Markets • A demand schedule is a table showing how much of a given product a household would be willing to buy at different prices • Demand curves are usually derived from demand schedules Microeconomics - 63 - The Firm’s Short-Run and Long-Run Supply Curves u Short-Run Supply Curve u The portion of its marginal cost curve that lies above average variable cost u Long-Run Supply Curve u The marginal cost curve above the minimum point of its average total cost curve Coming Next Monopoly Chapter The Long Run: Market Supply with Entry and Exit u At the end of the process of entry and exit, firms that remain must be making zero economic profit u The process of entry & exit ends only when price and average total cost are driven to equality u Long-run equilibrium must have firms operating at their efficient scale Microeconomics CHAPTER - 64 - Pure Monopoly FOUR MARKET MODELS Pure Monopoly: • Single Seller • No Close Substitutes • Price Maker • Blocked Entry • Nonprice Competition Pure Competition Monopolistic Competition Oligopoly Pure Monopoly Market Structure Continuum • The Natural Monopoly Case Legal Barriers to Entry • Ownership or Control of Essential Resources • … THE NATURAL MONOPOLY CASE Average Total Cost BARRIERS TO ENTRY Economies of Scale $20 15 ATC 10 If ATC declines over extended output, least-cost production is realized only if there is one producer - a natural monopoly 50 100 Quantity 200 Microeconomics - 65 - MONOPOLY REVENUES & COSTS Revenue Data Quantity Price of (Average Total Marginal Output Revenue) Revenue Revenue MONOPOLY REVENUES & COSTS Cost Data Average Total Cost Profit + Total Marginal or loss Cost Cost - $100 x $172 = $ = - $100 Revenue Data Quantity Price of (Average Total Marginal Output Revenue) Revenue Revenue Cost Data Average Total Cost Profit + Total Marginal or loss Cost Cost $172 $ $100 90 - $100 ] $162 ] x 162 = 162 $190.00 - 190 = - 28 MR = $162 – = $162 MC = $190 – 100 = $90 MR > MC Loss Improvement from -$100 to -$28 Check next unit of output! MONOPOLY REVENUES & COSTS Revenue Data Quantity Price of (Average Total Marginal Output Revenue) Revenue Revenue 10 $172 $ ] 162 162 ] 152 304 ] 142 426 ] 132 528 ] 122 610 ] 112 672 ] 102 714 ] 92 736 ] 82 738 ] 72 720 MONOPOLY REVENUES & COSTS Cost Data Average Total Cost Profit + Total Marginal or loss Cost Cost $100 ] $162 $190.00 190 ] 142 135.00 270 ] 122 113.33 340 ] 102 100.00 400 ] 82 94.00 470 ] 62 91.67 550 ] 42 91.43 640 ] 22 93.73 750 ] 97.78 880 ] - 18 103.00 1030 90 80 70 60 70 80 90 110 130 150 - $100 - 28 + 34 + 86 + 128 + 140 + 122 + 74 - 14 - 142 - 310 Revenue Data Quantity Price of (Average Total Marginal Output Revenue) Revenue Revenue Cost Data Average Total Cost Profit + Total Marginal or loss Cost Cost Can0you $ 0profit $172see - $100 ] $162 MR$100 > ]= 90 MC 162 162 maximization? ] 142 $190.00 190 ] 80 - 28 10 152 142 132 122 112 102 92 82 72 304 ] 122 426 ] 102 528 ] 82 610 ] 62 672 ] 42 714 ] 22 736 ] 738 ] - 18 720 135.00 270 ] 113.33 340 ] 100.00 400 ] 94.00 470 ] 91.67 550 ] 91.43 640 ] 93.73 750 ] 97.78 880 ] 103.00 1030 70 + 34 60 + 86 70 + 128 80 + 140 90 + 122 110 + 74 - 14 130 142 150 - 310 Microeconomics - 66 - MONOPOLY REVENUES & COSTS $172 $ ] 162 162 ] 304 152 ] 142 426 ] 132 528 ] 122 610 ] 112 672 ] 102 714 ] 92 736 ] 82 738 ] 72 720 10 PRICE Cost Data Average Total Cost Profit + Total Marginal or loss Cost Cost $100 ] $162 $190.00 190 ] 142 135.00 270 ] 122 113.33 340 ] 102 100.00 400 ] 82 94.00 470 ] 62 91.67 550 ] 42 91.43 640 ] 22 93.73 750 ] 97.78 880 ] - 18 103.00 1030 90 80 70 60 70 80 90 110 130 150 PRICE 150 MR 50 D Q 10 11 12 13 14 15 16 17 18 $750 500 TR 250 Q 10 11 12 13 14 15 16 17 18 OUTPUT AND PRICE MARGINAL & TOTAL REVENUE Elastic Elastic $200 200 - $100 - 28 + 34 + 86 + 128 + 140 + 122 + 74 - 14 - 142 - 310 REVENUE Revenue Data Quantity Price of (Average Total Marginal Output Revenue) Revenue Revenue MARGINAL & TOTAL REVENUE Inelastic PROFIT MAXIMIZATION $200 200 150 RULE MR=MC? PROFIT/ product 50 MR D Q REVENUE 10 11 12 13 14 15 16 17 18 $750 500 price, cost & revenue 175 100 150 $122 125 $94 100 MC PROFIT AC D 75 50 TR MR = MC 25 250 Q 10 11 12 13 14 15 16 17 18 MR 10 Q Microeconomics - 67 - OUTPUT AND PRICE Loss Minimization 200 Pm > produce 175 Price, costs and revenue Price Discrimination AVC, Lỗ Mỗi SP • First Degree Price Discrimination – MC AC AVC 150 A 125 loss Pm Charge a separate price to each customer: the maximum or reservation price they are willing to pay 100 V D 75 50 MR = MC 25 MR Qm 10 Q Additional Profit From Perfect First-Degree Price Discrimination • Question – Why would a producer have difficulty in achieving first-degree price discrimination? • Answer 1) Too many customers (impractical) Second-Degree Price Discrimination Second-degree price discrimination is pricing according to quantity consumed or in blocks $/Q P1 Without discrimination: P = P0 and Q = Q0 With second-degree discrimination there are three prices P1, P2, and P3 (e.g electric utilities) P0 P2 AC MC P3 D 2) Could not estimate the reservation price for each customer MR Q1 1st Block Q0 Q2 Q3 2nd Block 3rd Block Quantity Microeconomics - 68 - Second-Degree Price Discrimination $/Q Economies of scale permit: •Increase consumer welfare •Higher profits P1 P0 P2 AC MC P3 Third Degree Price Discrimination • 1) Divides the market into twogroups 2) Each group has its own demand function (different price elasticities of demand ) D MR Q1 1st Block Q0 Q2 Q3 Quantity 2nd Block 3rd Block Intertemporal Price Discrimination and Peak-Load Pricing • Separating the Market With Time – Initial release of a product, the demand is inelastic Intertemporal Price Discrimination and Peak-Load Pricing Peak-Load Pricing • Demand for some products may peak at particular times • Book – • Movie – • Computer – Rush hour traffic Electricity - late summer afternoons Ski resorts on weekends Microeconomics Intertemporal Price Discrimination and Peak-Load Pricing Peak-Load Pricing • Capacity restraints will also increase MC - 69 - The Two-Part Tariff • The purchase of some products and services can be separated into two decisions, and therefore, two prices • Increased MR and MC would indicate a higher price The Two-Part Tariff • Examples 1) Park • Pay to enter • Pay for rides and food within the park 2) Tennis Club • Pay to join • Pay to play Bundling • Bundling is packaging two or more products to gain a pricing advantage Microeconomics - 70 - Ceiling Pricing Bundling – Selling both as a bundle and separately P1 • Pure Bundling – Profit in the absence of intervention Profit (intervention)MC P • Mixed Bundling AC Pmax Selling only a package D MR = MC MR Q1 Tax Tax (per unit) Profit after tax P Q2 Profit after tax P MC2 MC MC1 AC2 P1 P* AC2 P* AC1 AC1 D = AR D = AR MR Q1 Q* MR Q Q* Q Q Microeconomics - 71 - Next Monopolistic Competition & Oligopoly Chapter Microeconomics - 72 - FOUR MARKET MODELS Monopolistic Competition: CHAPTER Monopolistic Competition and Oligopoly CHARACTERISTICS Relatively Large Number of Sellers •Small Market Shares •Independent Action •Relatively Large Number of Sellers •Differentiated Products •Easy Entry and Exit Pure Competition Monopolistic Competition Oligopoly Pure Monopoly Market Structure Continuum CHARACTERISTICS Differentiated Products • Product Attributes • Service • Location • Brand Names and Packaging • Some Control Over Price • Easy Entry and Exit • Advertising Microeconomics - 73 - OUTPUT AND PRICE OUTPUT AND PRICE MC New entrance MC New entrance AC AC Price & costs Price & costs Firm’s demand decrease P1 A1 Profit in short - run D P1 A1 Profit in short - run D MR Q1 MR Q1 Q Q A Monopolistically Competitive Firm in the Short and Long Run OUTPUT AND PRICE Long run equilibrium MC Economic profit = AC $/Q Short Run $/Q MC Long Run MC AC P3 = A3 AC Price & costs PSR PLR DSR DLR D MRSR MR Q3 QSR Q Quantity MRLR QLR Quantity Microeconomics - 74 - FOUR MARKET MODELS Oligopoly: • A Few Large Producers • Homogeneous or Differentiated Products • Control Over Price, But Mutual Interdependence •Strategic Behavior • Entry Barriers Pure Pure Monopolistic Competition Competition Oligopoly Monopoly THREE OLIGOPOLY MODELS No Standard Model due to - Diversity of Oligopolies - Complications of Interdependence Alternative Models: – Kinked Demand Curve – Cartels and Collusion Market Structure Continuum KINKED DEMAND THEORY: KINKED DEMAND THEORY: NONCOLLUSIVE OLIGOPOLY NONCOLLUSIVE OLIGOPOLY The rival’s demand and marginal revenue curves Price Price The firm’s demand and marginal revenue curves D2 D1 Quantity MR1 D1 Quantity MR1 MR2 Microeconomics - 75 - KINKED DEMAND THEORY: KINKED DEMAND THEORY: NONCOLLUSIVE OLIGOPOLY Rivals tend to follow a price cut or ignore a price increase Price Price NONCOLLUSIVE OLIGOPOLY Rivals tend to follow a price cut D2 D1 Quantity D2 MR2 D1 MR1 Quantity MR2 MR1 KINKED DEMAND THEORY: KINKED DEMAND THEORY: NONCOLLUSIVE OLIGOPOLY NONCOLLUSIVE OLIGOPOLY Effectively creating a kinked demand curve Price Price Effectively creating a kinked demand curve D2 D1 Quantity MR1 MR2 D Quantity Microeconomics - 76 - KINKED DEMAND THEORY: KINKED DEMAND THEORY: NONCOLLUSIVE OLIGOPOLY NONCOLLUSIVE OLIGOPOLY Profit maximization MR = MC occurs at the kink Effectively creating a kinked demand curve MC1 Price Price MC1 MR2 MR2 MC2 MC2 D Quantity MR1 D Quantity MR1 KINKED DEMAND THEORY: NONCOLLUSIVE OLIGOPOLY This behavior can set off a price war Price MC1 MR2 MC2 D Quantity MR1 Cartels • Characteristics 1) Explicit agreements to set output and price 2) May not include all firms Microeconomics - 77 - Cartels • Characteristics 4) Conditions for success • No cheating • Potential of monopoly power inelastic demand ... our economy • Suggest ways to make that future even better Microeconomics • Micro • Micro comes from Greek word mikros, meaning “small” • Microeconomics • Study of behavior of individual households,... per meal Utils Total Utility (utils) TOTAL AND MARGINAL UTILITY Marginal Utility (utils) Microeconomics 12 Microeconomics - 30 - UTILITY MAXIMIZING COMBINATION $ 10 income Unit of product First... AVC Average Total Costs = ATC (AC) Marginal Cost = MC Costs (dollars) Microeconomics MC AVC Quantity Quantity of output Microeconomics - 49 - Relationship Between Marginal Cost and Average Total