1. 1 © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair The Scope and Method of Economics Appendix: How to Read and Understand Graphs Prepared by: Fernando Quijano and Yvonn Quijano

2. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 2 of 33 How a simple economy operates Using the circular flow of income figure illustrates this. It shows how money flows around the economy. 1-businesses or producers buy land, labor, and capital from households (the users of goods and services 2- households receive rent, wages, interest, and profit (income ) in returns 3- the money they earn is spent. 4- businesses receive rent, wages, profit and interest According to this simple circulation: Households income (Y) is spent on goods & services (E) which are produced by businesses (O). Y = E =O

3. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 3 of 33 More Complex Economy In practice households do not spend all their earnings. There are Withdrawals and Injections. Injections in the economy Investment (I) spending on fixed assets. Government spending (G)grants. Exports (X) Withdrawals: Savings (S). Taxation (T). Imports (M).

4. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 4 of 33 GNP: The value of a country’s economic activities. How to measure GNP? Income Method: All income earned by households. Output method: All Goods and services produced by businesses.

5. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 5 of 33 Expenditure Method: Adding Consumers, Government expenditure, bus investment, exports minus imports. Called aggregate demand Y = C+I+G+(X-M). Y equal to GNP. (y: GNP, c: consumer, g: expenditure of gov, (x-m) export-import) GDP: GNP less net earning from property overseas. Income = output = expenditure this true in circular flows of income

6. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 6 of 33 Equilibrium If injections were the same as withdrawals, the money flowing around the circular flow would remain the same (equilibrium). -If injection = withdrawals income remains the same. -If injection > withdrawal income will rise. -If injection< withdrawals income will decrease

7. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 7 of 33 Equilibrium does not mean every one is employed. Deflationary Gap: The unemployment in the economy. Keynesians argue it is the role of the government to fill any gap that exist by spending more than it receives from tax; known budget deficit

8. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 8 of 33 The Study of Economics Economics is the study of how individuals and societies choose to use the scarce resources that nature and previous generations have provided.

9. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 9 of 33 Why Study Economics? An important reason for studying economics is to learn a way of thinking. Three fundamental concepts: Opportunity cost Marginalism, and Efficient markets

10. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 10 of 33 Opportunity Cost Opportunity cost is the best alternative that we forgo, or give up, when we make a choice or a decision. Nearly all decisions involve trade-offs.

11. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 11 of 33 Marginalism In weighing the costs and benefits of a decision, it is important to weigh only the costs and benefits that arise from the decision.

12. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 12 of 33 Marginalism For example, when a firm decides whether to produce additional output, it considers only the additional (or marginal cost), not the sunk cost. Sunk costs are costs that cannot be avoided, regardless of what is done in the future, because they have already been incurred.

13. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 13 of 33 Efficient Markets An efficient market is one in which profit opportunities are eliminated almost instantaneously. There is no free lunch! Profit opportunities are rare because, at any one time, there are many people searching for them.

14. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 14 of 33 More Reasons to Study Economics The study of economics is an essential part of the study of society. Economic decisions often have enormous consequences. During the Industrial Revolution, new manufacturing technologies and improved transportation gave rise to the modern factory system.

15. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 15 of 33 More Reasons to Study Economics An understanding of economics is essential to an understanding of global affairs. Voting decisions also require a basic understanding of economics.

16. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 16 of 33 The Scope of Economics Microeconomics is the branch of economics that examines the behavior of individual decision-making units—that is, business firms and households.

17. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 17 of 33 The Scope of Economics Macroeconomics is the branch of economics that examines the behavior of economic aggregates— income, output, employment, and so on—on a national scale.

18. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 18 of 33 The Scope of Economics Examples of microeconomic and macroeconomic concerns ProductionPricesIncomeEmployment MicroeconomicsProduction/Output in Individual Industries and Businesses How much steel How many offices How many cars Price of Individual Goods and Services Price of medical care Price of gasoline Food prices Apartment rents Distribution of Income and Wealth Wages in the auto industry Minimum wages Executive salaries Poverty Employment by Individual Businesses & Industries Jobs in the steel industry Number of employees in a firm MacroeconomicsNational Production/Output Total Industrial Output Gross Domestic Product Growth of Output Aggregate Price Level Consumer prices Producer Prices Rate of Inflation National Income Total wages and salaries Total corporate profits Employment and Unemployment in the Economy Total number of jobs Unemployment rate

19. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 19 of 33 The Method of Economics Positive economics studies economic behavior without making judgments. It describes what exists and how it works.

20. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 20 of 33 The Method of Economics Normative economics, also called policy economics, analyzes outcomes of economic behavior, evaluates them as good or bad, and may prescribe courses of action.

21. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 21 of 33 The Method of Economics Positive economics includes: Descriptive economics, which involves the compilation of data that describe phenomena and facts. Economic theory, which involves building models of behavior. An economic theory is a general statement of cause and effect, action and reaction.

22. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 22 of 33 Theories and Models Theories involve models, and models involve variables. A model is a formal statement of a theory. Models are descriptions of the relationship between two or more variables.

23. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 23 of 33 Theories and Models Ockham’s razor is the principle that irrelevant detail should be cut away. Models are simplifications, not complications, of reality.

24. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 24 of 33 Theories and Models A variable is a measure that can change from observation to observation. The ceteris paribus device is part of the process of abstraction. Using the ceteris paribus, or all else equal, assumption, economists study the relationship between two variables while the values of other variables remain constant.

25. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 25 of 33 Theories and Models Pitfalls to avoid in formulating economic theory: The post hoc, ergo propter hoc fallacy refers to a common error made in thinking about causation: If event A happened before event B, it is not necessarily true that A caused B. The fallacy of composition is the erroneous belief that what is true for a part is also true for the whole.

26. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 26 of 33 The Method of Economics Empirical economics refers to the collection and use of data to test economic theories. Many data sets are available to facilitate economic research. They are collected by both government agencies and private companies,

27. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 27 of 33 Economic Policy Criteria for judging economic outcomes: Efficiency, or allocative efficiency. An efficient economy is one that produces what people want at the least possible cost. Equity, or fairness of economic outcomes.

28. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 28 of 33 Economic Policy Criteria for judging economic outcomes: Economic growth, or an increase in the total output of an economy. Economic stability, or the condition in which output is steady or growing, with low inflation and full employment of resources.

29. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 29 of 33 Review Terms and Concepts ceteris paribus ceteris paribus descriptive economics descriptive economics economic growth economic growth economic theory economic theory economics efficiency efficient market efficient market empirical economics empirical economics equity fallacy of composition fallacy of composition Industrial Revolution Industrial Revolution macroeconomics microeconomics model normative economics normative economics ockham’s razor ockham’s razor opportunity cost opportunity cost positive economics positive economics post hoc, ergo propter hoc post hoc, ergo propter hoc stability sunk costs sunk costs variable

30. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 30 of 33 Appendix: How to Read and Understand Graphs A graph is a two- dimensional representation of a set of numbers or data.

31. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 31 of 33 Appendix: How to Read and Understand Graphs A time series graph shows how a single variable changes over time.

32. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 32 of 33 Appendix: How to Read and Understand Graphs The Cartesian coordinate system is the most common method of showing the relationship between two variables. The horizontal line is the X-axis and the vertical line the Y-axis. The point at which the horizontal and vertical axes intersect is called the origin.

33. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 33 of 33 Appendix: How to Read and Understand Graphs The point at which the line intersects the Y-axis (point a ) is called the Y- intercept.The point at which the line intersects the Y-axis (point a ) is called the Y- intercept. The Y-intercept, is the value of Y when X = 0.The Y-intercept, is the value of Y when X = 0.

34. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 34 of 33 Appendix: How to Read and Understand Graphs The slope of the line indicates whether the relationship between the variables is positive or negative.The slope of the line indicates whether the relationship between the variables is positive or negative. The slope of the line is computed as follows:The slope of the line is computed as follows:

35. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 35 of 33 Appendix: How to Read and Understand Graphs This line slopes upward, indicating that there seems to be a positive relationship between income and spending. Points A and B, above the 45° line, show that consumption can be greater than income.

36. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 36 of 33 Appendix: How to Read and Understand Graphs A downward-sloping line describes a negative relationship between X and Y. An upward-sloping line describes a positive relationship between X andY. An upward-sloping line describes a positive relationship between X and Y.

37. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 37 of 33 Appendix: How to Read and Understand Graphs

38. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 38 of 33 Appendix: How to Read and Understand Graphs

39. © 2004 Prentice Hall Business PublishingPrinciples of Economics, 7/eKarl Case, Ray Fair C H A P T E R 1: The Scope and Method of Economics 39 of 33 Appendix: How to Read and Understand Graphs Cartesian coordinate system Cartesian coordinate system graph negative relationship negative relationship origin positive relationship positive relationship slope time series graph time series graph X-axis Y-axis Y-intercept