1. The scope and method of Economics
School of Natural and Social Sciences
Department of Economics and Business, Lehman College
Lecture 1 – Welcome to Economics!
The scope and method of Economics
Presentation clipart by PresenterMedia
Alexander Núñez Torres, PhD
Assistant Professor,
Department of Economics and Business
These slides are based on Principles of Macroeconomics by Steven A. Greenlaw and Timothy Taylor – OpenStax (2017). Unless otherwise noted, they are licensed under an Attribution-NonCommercial-ShareAlike 4.0 International.

2. Schedule Key Concepts & Definitions Why Study economics?
Identify three key reasons to study economics
Microeconomics and Macroeconomics
Describe microeconomics, macroeconomics
Describe the diverse fields of economics
The Method of Economics: How theories and models are used
Positive and normative questions
Theories and models
Identify the four main goals of economic policy

3. Concept & Definitions Economics
The study of how individuals and societies choose to use the scarce resources that nature and previous generations have provided.
The key word in the definition is choose.
Economics is a behavioral, or social, science.
Economics is the study of how people make choices.

4. Concept & Definitions Economics has three fundamental concepts:
Opportunity costs: The best alternative that we forgo, or give up, when we make a choice or decision.
Marginalism: The process of analyzing the additional or incremental costs or benefits arising from a choice or decision.
Efficient market: A market in which profit opportunities are eliminated almost instantaneously.

5. Why Study Economics?
Just three reasons of why one should study economics
To learn a way of thinking: The study of economics teaches us a way of thinking and helps us make decisions. When you read articles about economic issues, you will understand and be able to evaluate the writer’s argument.
To understand society: Economics decisions shape the physical environment and influence the character of society. Think about the effect of technology on the cities or the effects of global warming, world poverty, conflicts between countries.
To be an informed citizen

6. The Scope of Economics Microeconomics and Macroeconomics
Microeconomics: The branch of economics that examines the functioning of individual industries and the behavior of individual decision-making units—that is, firms and households. It sees and examines the firm, the industry. It sees the “trees”.
Macroeconomics: The branch of economics that examines the economic behavior of aggregates—income, employment, output, and so on—on a national scale. It looks at the whole, the aggregate. It sees the “forest”.

7. The Scope of Economics Diverse fields of economics
Behavioral economics: Do aggregate household savings increase when we automatically enroll people in savings programs and let them opt out as opposed to requiring them to sign up?
Econometrics: What inferences can we make based on conditional moment inequalities?
Economic development: Does increasing employment opportunities for girls in developing nations increase their educational achievements?
Economic history: How did the growth of railroads and improvement in transportation more generally change the U.S. banking systems in the nineteenth century?

8. The Scope of Economics Diverse fields of economics
Environmental economics: What effect would a tax on carbon have on emissions? Is a tax better or worse than rules?
Finance: Is high frequency trading socially beneficial?
Health economics: Do co-pays by patients change the choice and use of medicines by insured patients?
The history of economic thought: How did Aristotle think about just prices?
Industrial organization: How do we explain price wars in the airline industry

9. The Scope of Economics Diverse fields of economics
International economics: What are the benefits and costs of free trade? Does concern about the environment change our views of free trade?
Labor economics: Will increasing the minimum wage decrease employment opportunities?
Law and economics: Does the current U.S. patent law increase or decrease the rate of innovation?
Public economics: Why is corruption more widespread in some countries than in others?
Urban and regional economics: Do enterprise zones improve employment opportunities in central cities?

10. The method of economics
Positive and normative questions on economics
Positive economics: An approach to economics that seeks to understand behavior and the operation of systems without making judgments. It describes what exists and how it works.
Normative economics: An approach to economics that analyzes outcomes of economic behavior, evaluates them as good or bad, and may prescribe courses of action. Also called policy economics.

11. The method of economics
Theories and Models
Model A formal statement of a theory, usually a mathematical statement of a presumed relationship between two or more variables.
Variable A measure that can change from time to time or from observation to observation.
Ockham’s razor The principle that irrelevant detail should be cut away.
ceteris paribus, or “all else equal”. It is used to describe the relationship between two or more variables, while assuming the other variables remain constant.

12. The method of economics
Theories and Models
Expressing Models in Words, Graphs, and Equations capture the quantitative side of economic observations and predictions.
Economists are interested in cause and effect, but sorting out causality from correlation is not always easy.
What is the difference between correlation and causality?
Why is this important?
Correlation means a mutual relationship or connection between two or more things
Causality means that A causes B

13. The method of economics
Correlation and inferences (Example of what not to do)
Americans and English eat a lot of fat food. There is a high rate of cardiovascular diseases in US and UK.
French eat a lot of fat food, but they have a low(er) rate of cardiovascular diseases.
Americans and English drink a lot of alcohol. There is a high rate of cardiovascular diseases in US and UK.
Italians drink a lot of alcohol but, again, they have a low(er) rate of cardiovascular diseases.
The conclusion? Eat and drink what you want. And you have a higher chance of getting a heart attack if you speak English!
Correlation means a mutual relationship or connection between two or more things
Causality means that A causes B

14. The method of economics
Economic policy
Four criteria are important in judging economic outcomes:
Efficiency: An efficient economy is one that produces what people want at the least possible cost.
Equity: Fairness
Economic growth: An increase in the total output of an economy.
Stability: A condition in which national output is growing steadily, with low inflation and full employment of resources.
Where would you assign the pros and cons arguments for raising the minimum wage?
Cons: Business competitions (Equity and Efficiency), a firms ability to weather downturns by lowering costs (Efficiency and Stability), Inflationary pressures (Stability and Economic Growth)
Pros: Wealth Inequality (Equity, Economic Growth, Stability (due to social spending))

15. The scope and method of Economics
School of Natural and Social Sciences
Department of Economics and Business, Lehman College
Lecture 1 – Welcome to Economics!
The scope and method of Economics
Presentation clipart by PresenterMedia
Alexander Núñez Torres, PhD
Assistant Professor,
Department of Economics and Business