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1、 2009 South-Western, a part of Cengage Learning, all rights reservedC H A P T E RThinking Like An EconomistThinking Like An EconomistEconomicsP R I N C I P L E S O FP R I N C I P L E S O FN. Gregory MankiwN. Gregory MankiwPremium PowerPoint Slides by Ron Cronovich2In this chapter, In this chapter, l
2、ook for the answers to these questions:look for the answers to these questions:What are economists two roles? How do they differ? What are models? How do economists use them? What are the elements of the Circular-Flow Diagram? What concepts does the diagram illustrate? How is the Production Possibil
3、ities Frontier related to opportunity cost? What other concepts does it illustrate? What is the difference between microeconomics and macroeconomics? Between positive and normative? 2THINKING LIKE AN ECONOMIST3The Economist as ScientistEconomists play two roles:1. Scientists: try to explain the worl
4、d 2. Policy advisors: try to improve itIn the first, economists employ the scientific method, the dispassionate development and testing of theories about how the world works. THINKING LIKE AN ECONOMIST4Assumptions & ModelsAssumptions simplify the complex world, make it easier to understand. Example:
5、 To study international trade, assume two countries and two goods. Unrealistic, but simple to learn and gives useful insights about the real world. Model: a highly simplified representation of a more complicated reality. Economists use models to study economic issues. THINKING LIKE AN ECONOMIST5Some
6、 Familiar ModelsA road mapTHINKING LIKE AN ECONOMIST6Some Familiar ModelsA model of human anatomy from high school biology classTHINKING LIKE AN ECONOMIST7Some Familiar ModelsA model airplaneTHINKING LIKE AN ECONOMIST8Some Familiar ModelsThe model teeth at the dentists officeDont forget to floss!THI
7、NKING LIKE AN ECONOMIST9Our First Model: The Circular-Flow Diagram The Circular-Flow Diagram: a visual model of the economy, shows how dollars flow through markets among households and firms Two types of “actors”: households firms Two markets: the market for goods and services the market for “factor
8、s of production”THINKING LIKE AN ECONOMIST10Factors of ProductionFactors of production: the resources the economy uses to produce goods & services, including labor land capital (buildings & machines used in production)THINKING LIKE AN ECONOMIST11FIGURE 1: The Circular-Flow DiagramHouseholds: Own the
9、 factors of production, sell/rent them to firms for income Buy and consume goods & servicesHouseholdsFirmsFirms: Buy/hire factors of production, use them to produce goods and services Sell goods & servicesTHINKING LIKE AN ECONOMIST12FIGURE 1: The Circular-Flow DiagramMarkets for Factors of Productio
10、nHouseholdsFirmsIncomeWages, rent, profitFactors of productionLabor, land, capitalSpendingG & S boughtG & S soldRevenueMarkets for Goods & ServicesTHINKING LIKE AN ECONOMIST13Our Second Model: The Production Possibilities Frontier The Production Possibilities Frontier (PPF): a graph that shows the c
11、ombinations of two goods the economy can possibly produce given the available resources and the available technology Example: Two goods: computers and wheat One resource: labor (measured in hours) Economy has 50,000 labor hours per month available for production.PPF Example Producing one computer re
12、quires 100 hours labor. Producing one ton of wheat requires 10 hours labor.5,00004,0001002,5002501,00040050,000040,00010,00025,00025,00010,00040,0000500050,000EDCBAWheatComputersWheatComputersProductionEmployment of labor hoursTHINKING LIKE AN ECONOMIST15Point on graphProductionCom- putersWheatA5000
13、B4001,000C2502,500D1004,000E05,000ABCDEPPF ExampleA.On the graph, find the point that represents (100 computers, 3000 tons of wheat), label it F. Would it be possible for the economy to produce this combination of the two goods? Why or why not? B.Next, find the point that represents (300 computers,
14、3500 tons of wheat), label it G. Would it be possible for the economy to produce this combination of the two goods?A C T I V E L E A R N I N G A C T I V E L E A R N I N G 1 1Points off the PPFPoints off the PPF16A C T I V E L E A R N I N G A C T I V E L E A R N I N G 1 1AnswersAnswers17Point F: 100
15、computers, 3000 tons wheat Point F requires 40,000 hours of labor. Possible but not efficient: could get more of either good w/o sacrificing any of the other.FA C T I V E L E A R N I N G A C T I V E L E A R N I N G 1 1AnswersAnswers18Point G: 300 computers, 3500 tons wheatPoint G requires 65,000 hou
16、rs of labor. Not possible because economy only has 50,000 hours.GTHINKING LIKE AN ECONOMIST19The PPF: What We Know So FarPoints on the PPF (like A E) possible efficient: all resources are fully utilizedPoints under the PPF (like F) possible not efficient: some resources underutilized (e.g., workers unemployed, f
