Chapter 1: What is Economics? — Foundations of Microeconomics

What is Economics?

Introduction to Economics

Economics is the social science that studies how individuals, businesses, governments, and societies make choices to allocate scarce resources. All economic questions arise because our wants exceed the resources available, a condition known as scarcity. Because of scarcity, choices must be made, and these choices are influenced by incentives—rewards or penalties that encourage or discourage actions.

• Scarcity: The fundamental economic problem of having seemingly unlimited human wants in a world of limited resources.

• Economics: The study of how people choose to allocate scarce resources to satisfy their wants.

• Incentive: A reward or penalty that motivates behavior.

Microeconomics vs. Macroeconomics

• Microeconomics (Econ 101): Focuses on individual choices and the behavior of individual units, such as households and firms.

• Macroeconomics (Econ 102): Studies the economy as a whole, including issues like inflation, unemployment, and economic growth.

The Scope of Economics: Two Big Questions

What, How, and For Whom?

Economics seeks to answer three core questions:

• What goods and services are produced?

• How are these goods and services produced?

• For whom are goods and services produced?

Goods and services are produced using factors of production (inputs):

• Land: Natural resources

• Labor: Human effort, including human capital (skills and knowledge)

• Capital: Physical capital such as machinery, buildings, and tools

• Entrepreneurship: The human resource that organizes land, labor, and capital

Production is the process of transforming inputs into outputs using technology.

Distribution of Income

The distribution of goods and services depends on the incomes earned by the owners of the factors of production:

• Land earns rent

• Labor earns wages

• Capital earns interest

• Entrepreneurship earns profit

Self-Interest vs. Social Interest

Choices made in self-interest may or may not align with the social interest. Social interest has two dimensions:

• Efficiency: Resource use is efficient if it is not possible to make someone better off without making someone else worse off.

• Equity: Fairness in the distribution of resources, though definitions of fairness vary among economists.

The Economic Way of Thinking

Rational Choices and Tradeoffs

Economists assume that people act rationally, making choices to maximize their benefit given their constraints. Every choice involves a tradeoff: giving up one thing to get something else.

• Opportunity Cost: The highest-valued alternative forgone when a choice is made. In economics, all costs are opportunity costs.

Marginal Analysis

Most choices are made at the margin, meaning people consider the consequences of incremental changes in resource use.

• Marginal Benefit (MB): The additional benefit from one more unit of an activity.

• Marginal Cost (MC): The additional cost from one more unit of an activity.

Rules of Marginal Analysis:

• If MB > MC, do more of the activity.

• If MC > MB, do less of the activity.

Positive vs. Normative Statements

Economists distinguish between:

• Positive Statements: Statements that can be tested against facts (objective).

• Normative Statements: Statements that involve value judgments and cannot be tested (subjective).

The Scientific Method in Economics

Economists use the scientific method to build and test models:

1. Observation and measurement

2. Formulating hypotheses (economic models)

3. Testing models using empirical data (natural experiments, statistical investigations, economic experiments)

Models that consistently predict outcomes are called theories.

Ceteris Paribus Assumption

To isolate cause and effect, economists use the ceteris paribus assumption—holding all other variables constant except the one being studied.

Making and Using Graphs in Economics

Graphs in Economic Models

Graphs are used to illustrate relationships between economic variables. The slope of a curve shows the nature and strength of the relationship between two variables. Moving along a curve shows the effect of changing one variable, while shifting the curve shows the effect of changing a third variable held constant.

Relationships Involving More Than Two Variables

When more than two variables are involved, economists use the ceteris paribus assumption to analyze the relationship between two variables while holding others constant. If a third variable changes, the entire curve shifts, indicating a new relationship.

Skills and Careers in Economics

Economics majors develop critical-thinking, analytical, math, writing, and oral communication skills. These are highly valued in a variety of careers, and the number of economics jobs is expected to grow.

Summary Table: Factors of Production and Their Incomes

Factor of Production	Definition	Income Earned	Example
Land	Natural resources	Rent	Farmland, minerals
Labor	Human effort	Wages	Factory worker, teacher
Capital	Physical tools and machinery	Interest	Machines, computers
Entrepreneurship	Organization of resources	Profit	Business owner

Key Formulas

• Opportunity Cost: $Opportunity\ Cost = Value\ of\ Next\ Best\ Alternative$

• Profit: $Profit = Total\ Revenue - Total\ Cost$

• Slope of a Line: $Slope = \frac{\Delta y}{\Delta x}$

Additional info: This summary includes expanded academic context and examples to ensure the notes are self-contained and suitable for exam preparation.