Economics: Foundations and Models

Definition of Economics

Economics is the study of how individuals, households, firms, and societies make choices to allocate scarce resources to satisfy unlimited wants. It formalizes decision-making processes that everyone experiences in daily life.

• Key Point: Economics is not simply the study of the stock market, budgeting, or money. It is about choices and trade-offs.

• Key Point: Anyone who has made a decision has engaged in economic thinking.

• Example: Choosing between buying a new phone or saving money is an economic decision.

The Three Fundamental Questions of Economics

Every economy must answer three basic questions due to the problem of scarcity:

• 1. What goods and services will be produced? Consumers influence production through their purchasing decisions.

• 2. How will goods and services be produced? Firms decide on production methods based on cost and efficiency. For example, crosswalks may be painted by hand in Spain and by machine in the US due to differences in labor costs and technology.

• 3. Who will receive the goods and services? Distribution depends on factors like income, need, and market mechanisms.

• Key Point: These questions are answered in all economies, whether market-oriented or centralized.

Scarcity and Opportunity Cost

Scarcity arises because resources are limited while wants are unlimited. This leads to trade-offs and the necessity of making choices.

• Scarcity: Unlimited wants, limited resources.

• Resources: Land, nonhuman animal resources, labor/human capital, capital (man-made resources), technology, entrepreneurial ability.

• Opportunity Cost: The highest valued alternative that must be given up to engage in an activity.

• Example: The opportunity cost of attending college may be the income foregone from not working full-time.

Trade-offs and Decisions at the Margin

Because of scarcity, doing more of one activity requires doing less of another. Economics emphasizes decisions at the margin, which means considering the extra benefit or cost of a decision.

• Marginal Analysis: Evaluating decisions based on incremental changes.

• Example: Should Apple increase iPhone production from 240 million to 243 million? The decision depends on the marginal profit, not just total profit.

Positive vs. Normative Statements

Economics distinguishes between positive statements (factual) and normative statements (value judgments).

• Positive Statement: Concerned with what is. Example: "An increase in minimum wage will cause a decrease in employment among the least skilled."

• Normative Statement: Concerned with what ought to be. Example: "The income gains from a higher minimum wage are worth more than any slight reductions in employment."

Microeconomics vs. Macroeconomics

Microeconomics focuses on individual households and firms, while macroeconomics studies the economy as a whole, including inflation, unemployment, and economic growth.

• Microeconomics: Individual choices, markets, and firms.

• Macroeconomics: Aggregate outcomes, national income, and policy.

Voluntary Exchange and Self-Interest

Adam Smith argued that voluntary exchange is driven by self-interest, not benevolence. People trade goods and services to benefit themselves, which leads to mutual gains.

• Key Point: Voluntary exchange increases overall welfare.

• Example: Buying dinner from a baker benefits both the buyer and the seller.

Math Review for Economics

Number Lines and Coordinate Systems

Economics often uses number lines and coordinate systems to represent relationships between variables.

• Horizontal Number Line: Values increase as you move right.

• Vertical Number Line: Values increase as you move up.

• Coordinate System: Most economic graphs are in the first quadrant, where both x and y are positive.

Positive and Negative Relationships

Variables in economics can have positive or negative relationships.

• Positive Relationship: Both variables increase together. Example: Hours studied and GPA.

• Negative Relationship: One variable increases as the other decreases. Example: Hours of TV watched and GPA.

Slope

Slope measures the rate of change between two variables. It is calculated as rise over run.

• Formula:

• Example: If Y increases by 2 when X increases by 1, slope = 2/1 = 2.

Comparing Lines on a Graph

When comparing lines, the position and slope indicate which variable is greater at a given point.

• Key Point: At a given Y value, the line with the greater X value is further right.