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Microeconomics Basics

Sep 24, 2025

Overview

This lecture introduces foundational concepts in microeconomics, focusing on scarcity, opportunity cost, economic systems, production possibilities, comparative advantage, and marginal analysis.

Scarcity and Economic Resources

  • Scarcity is the inability of limited resources to satisfy unlimited human wants.
  • Scarce items typically have a positive price and require allocation systems.
  • Scarcity is distinct from shortage (temporary unavailability) and from needs (focus is on wants).
  • Factors of production are land (natural resources), labor (human effort), physical capital (machines/tools), and entrepreneurship (risk-taking organizers).

Economic Systems & Fundamental Questions

  • All economies must answer: What to produce, how to produce, and for whom to produce.
  • Command economies use government planners to make economic decisions.
  • Market economies rely on individuals and firms, emphasizing private property rights.
  • Most modern economies, like the U.S., are mixed systems leaning toward market organization.

Opportunity Cost & Types of Costs

  • Opportunity cost is the value of the next best alternative forgone when a choice is made.
  • Explicit cost is the actual money spent; implicit cost is the value of opportunities lost.
  • Total opportunity cost = explicit cost + implicit cost.

Production Possibilities Curve (PPC)

  • PPC shows maximum combinations of two goods that can be produced with fixed resources.
  • A bowed-out PPC indicates increasing opportunity costs; straight-line PPC indicates constant costs.
  • Points on the curve are efficient; inside is inefficient (unemployment); outside is impossible.
  • PPC can shift outward with more/better resources or technology, inward with loss, or outward for one good with specific technological advances.

Comparative and Absolute Advantage

  • Absolute advantage: ability to produce more with the same inputs or using fewer resources.
  • Comparative advantage: ability to produce a good at a lower opportunity cost.
  • For input questions: "it over" formula (resource for A divided by resource for B).
  • For output questions: "other over" formula (output of B divided by output of A).
  • Mutually beneficial trade terms fall between the opportunity costs of trading partners.

Marginal Analysis & Diminishing Utility

  • Marginal benefit generally decreases, and marginal cost increases with additional units.
  • Rational decision-makers act until marginal benefit equals marginal cost.
  • Diminishing marginal utility: each additional unit consumed gives less satisfaction.
  • Utility is maximized when the marginal utility per dollar is equal for all goods (MUx/Px = MUy/Py).

Key Terms & Definitions

  • Scarcity — Limited resources cannot meet unlimited wants.
  • Factors of production — Land, labor, capital, entrepreneurship.
  • Command economy — Central planners make economic decisions.
  • Market economy — Decisions are made by individuals and firms.
  • Opportunity cost — Value of the next best alternative forgone.
  • Explicit cost — Direct monetary payment for a choice.
  • Implicit cost — Value of lost opportunities.
  • Production Possibilities Curve (PPC) — Graph of possible production combinations.
  • Absolute advantage — Ability to produce more with given resources.
  • Comparative advantage — Ability to produce at a lower opportunity cost.
  • Marginal analysis — Study of additional costs and benefits.
  • Diminishing marginal utility — Decreasing satisfaction with each extra unit consumed.

Action Items / Next Steps

  • Review and practice PPC graphs, opportunity cost calculations, and comparative advantage problems.
  • Prepare for questions on marginal analysis and utility maximization for exams.
  • Suggested: Read the next unit and complete related practice problems.