Introduction to Economics

What is Economics?

Economics is the study of how individuals, firms, and societies allocate scarce resources to satisfy unlimited wants. It examines choices and trade-offs in the face of scarcity.

• Scarcity: The fundamental economic problem of having limited resources to meet unlimited wants.

• Choice: Because resources are scarce, choices must be made about their allocation.

Positive vs. Normative Economics

• Positive Economics: Describes and explains economic phenomena; statements can be tested and validated ("what is").

• Normative Economics: Involves value judgments about what the economy should be like ("what ought to be").

• Example: "An increase in the minimum wage will lead to higher unemployment" (positive). "The government should increase the minimum wage" (normative).

Microeconomics vs. Macroeconomics

• Microeconomics: Focuses on individual units such as households, firms, and markets.

• Macroeconomics: Studies the economy as a whole, including inflation, unemployment, and economic growth.

Ceteris Paribus

• Ceteris Paribus: Latin for "all other things held constant." Used to isolate the effect of one variable by holding others unchanged.

Rationality

• Rationality: The assumption that individuals and firms make decisions to maximize their utility or profit, given available information and constraints.

Scientific Method in Economics

• Economists use the scientific method to develop models, test hypotheses, and analyze data.

• Steps include observation, hypothesis formation, prediction, and empirical testing.

Common Fallacies

• Post Hoc ergo Propter Hoc: The fallacy of assuming that because one event follows another, the first caused the second.

• Fallacy of Composition: The error of assuming that what is true for an individual is also true for the group.

Opportunity Cost and Comparative Advantage

Opportunity Cost

Opportunity cost is the value of the next best alternative foregone when a choice is made.

• Example: If you spend time studying economics instead of working, your opportunity cost is the wage you could have earned.

Absolute and Comparative Advantage

• 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.

• Example: If Country A can produce both wheat and cars more efficiently than Country B, but has a lower opportunity cost for wheat, it has a comparative advantage in wheat.

Production Possibility Frontier (PPF)

Definition and Interpretation

The PPF is a curve showing the maximum attainable combinations of two goods that can be produced with available resources and technology.

• Points Inside the PPF: Inefficient use of resources.

• Points On the PPF: Efficient production, full use of resources.

• Points Outside the PPF: Unattainable with current resources.

Shifts in the PPF (Economic Growth)

• The PPF shifts outward with increases in resources, technology, or productivity (economic growth).

Shape of the PPF and the Law of Increasing Marginal Opportunity Cost

• The PPF is typically bowed outward due to the law of increasing marginal opportunity cost: as more of one good is produced, the opportunity cost of producing additional units increases.

Marginal Rate of Transformation (MRT)

• MRT: The slope of the PPF, representing the opportunity cost of one good in terms of the other.

• Formula:

Graphing the PPF

• Draw axes for two goods, plot attainable combinations, and connect to form the PPF curve.

Supply and Demand

Quantity Demanded and Quantity Supplied

• Quantity Demanded (Qd): The amount of a good consumers are willing and able to buy at a specific price.

• Quantity Supplied (Qs): The amount of a good producers are willing and able to sell at a specific price.

Law of Demand and Law of Supply

• Law of Demand: As price decreases, quantity demanded increases, ceteris paribus.

• Law of Supply: As price increases, quantity supplied increases, ceteris paribus.

Change in Quantity Demanded/Supplied vs. Change in Demand/Supply

• Change in Qd or Qs: Movement along the demand or supply curve due to a price change.

• Change in Demand or Supply: Shift of the entire curve due to non-price factors (e.g., income, tastes, technology).

Determinants of Demand and Supply

• Demand Shifters: Income, prices of related goods, tastes, expectations, number of buyers.

• Supply Shifters: Input prices, technology, expectations, number of sellers.

Market Equilibrium

• Equilibrium Price (P*) and Quantity (Q*): The price and quantity at which quantity demanded equals quantity supplied.

• Formula: Set and solve for P*.

Shortage and Surplus

• Shortage: Occurs when Qd > Qs at a given price; upward pressure on price.

• Surplus: Occurs when Qs > Qd at a given price; downward pressure on price.

Simultaneous Shifts of Demand and Supply

• When both curves shift, the effect on equilibrium price and quantity depends on the magnitude and direction of each shift.

• Example: If demand increases and supply decreases, price will rise, but the effect on quantity is ambiguous.

Price Floors and Price Ceilings

• Price Floor: A legal minimum price (e.g., minimum wage). If set above equilibrium, causes a surplus.

• Price Ceiling: A legal maximum price (e.g., rent control). If set below equilibrium, causes a shortage.

Summary Table: Key Concepts

Additional info: Academic context and examples have been added to expand on the brief points listed in the exam preview. Formulas and definitions are provided for clarity and exam preparation.