Basic Principles of Economics

Definition of Economics

Economics is the study of how individuals and societies choose to use scarce resources provided by nature and previous generations. The central problem in economics is scarcity, which forces people and societies to make choices about how to allocate limited resources.

• Scarcity: A situation where the ingredients for producing desired goods and services are insufficient to satisfy all wants at a zero price.

• Resources: The inputs used to produce goods and services, classified as:

  • Land: Anything provided by nature.

  • Labor: The mental and physical efforts of human beings.

  • Capital: Goods produced to produce other goods and services.

    • Physical Capital: Tools, machines, factories, etc.

    • Human Capital: Skills developed through training and education.

Three Fundamental Economic Questions

Every economy must answer the following questions:

• What to produce?

• How to produce?

• For whom to produce?

Types of Economic Systems

• Command Economy: A central authority decides what, how, and for whom to produce (e.g., North Korea).

• Free Market Economy: Markets determine production and distribution through supply and demand.

• Mixed Economy: Combines elements of both command and market economies.

• Market: Any place (physical or online) where buyers and sellers exchange goods and services.

Branches of Economics

• Microeconomics: Examines the functioning of individual industries and the behavior of individual decision-making agents (firms and households).

• Macroeconomics: Studies the behavior of economic aggregates such as income, employment, output, and economic growth on a national scale.

Positive vs. Normative Economics

• Positive Economics: Describes and predicts economic phenomena; statements are testable and objective.

• Normative Economics: Involves value judgments about what ought to be; statements are subjective and not testable.

The Scientific Method in Economics

• Make observations.

• Use inductive reasoning to form theories and hypotheses.

• Test hypotheses and theories.

• Modify hypotheses and theories as needed.

Introductory Economic Models

Reasoning in Economics

• Inductive Reasoning: Moves from specific observations to general rules.

• Deductive Reasoning: Applies general rules to reach specific conclusions.

Economic Models

Models are simplified representations of reality used to explain and predict economic phenomena. They focus on key variables and relationships, omitting irrelevant details (Ockham's Razor).

• Ockham's Razor: The principle that irrelevant details should be eliminated from models.

• Key Assumptions: People are rational and act in their own self-interest.

• Ex ante: Before the fact.

• Ex post: After the fact.

• Ceteris Paribus: All other things equal; used to isolate the effect of one variable.

Common Fallacies in Economic Reasoning

• Post hoc ergo propter hoc: Assuming that because one event follows another, the first caused the second.

• Fallacy of Composition: Assuming that what is true for one individual is true for the group as a whole.

Opportunity Cost

The opportunity cost of a choice is the value of the best alternative forgone when making a decision.

• Example: Attending college for a semester:

  • Tuition: $10,439

  • Books: $1,000

  • Forgone wages: $20/hr × 40 hrs/week × 15 weeks = $12,000

  • Total cost: $23,439

Production Possibilities Frontier (PPF)

Definition and Assumptions

The Production Possibilities Frontier (PPF) is a graph that shows all combinations of two goods or services that can be produced in a given period, assuming efficient use of all resources.

• Production occurs over a specific period.

• Resources are fixed.

• Resources are fully employed.

• Technology is fixed.

• Consumer Goods: Goods produced for direct consumption.

• Capital Goods: Goods produced to create other goods.

PPF Table Example

Graphical Properties of the PPF

• The PPF is downward sloping, reflecting opportunity costs.

• The PPF is bowed out (concave), illustrating the law of increasing opportunity costs.

• Any point on the PPF is efficient; points inside are inefficient, and points outside are unattainable.

Calculating Slope and Marginal Rate of Transformation (MRT)

• Slope of the PPF: Measures the opportunity cost of one good in terms of the other.

• Formula:

• Marginal Rate of Transformation (MRT): The rate at which society can trade one good for another in production; numerically equal to the absolute value of the PPF's slope.

The Law of Increasing Opportunity Cost

As more of one good is produced, the opportunity cost of producing additional units increases because resources are not equally suited to all types of production.

Sunk Costs

• Sunk Costs: Costs that have already been incurred and cannot be recovered.

• Decision-Making Principle: Sunk costs should not be considered when making future economic decisions; only opportunity costs matter.

• Example: If you paid for a ticket to a baseball game and are offered $500 to sell it, the original ticket price is a sunk cost and should not affect your decision.

Points Inside, On, and Outside the PPF

• Inside the PPF: Indicates underutilization or inefficiency (e.g., unemployment).

• On the PPF: Efficient use of resources.

• Outside the PPF: Currently unattainable with existing resources and technology.

Shifts in the PPF and Economic Growth

• Causes of PPF Shifts: Changes in resources or technology.

• Economic Growth: Represented by an outward shift of the PPF, allowing more of both goods to be produced.

• Reducing unemployment moves production closer to the PPF but does not shift it outward.

Absolute Advantage, Comparative Advantage, and Gains from Trade

These concepts explain how individuals or nations can benefit from specializing in the production of goods for which they have a comparative advantage and trading with others.

• Absolute Advantage: The ability to produce more of a good with the same resources than another producer.

• Comparative Advantage: The ability to produce a good at a lower opportunity cost than another producer.

• Gains from Trade: By specializing according to comparative advantage and trading, all parties can achieve consumption levels beyond their individual PPFs.

Additional info: The notes reference images and graphs, but the main concepts are described in text. The table has been recreated in HTML. The concepts of absolute and comparative advantage are introduced but not elaborated; further study is recommended for these topics.