💡

Introduction to Economics Concepts

Aug 23, 2025

Overview

This lecture introduces economics as a way of understanding everyday decisions, focusing on four major concepts: opportunity cost, sunk cost fallacy, marginal benefit/cost, and market equilibrium, using real-life examples like dating and ride-sharing.

Economics as a Decision-Making Lens

  • Economics is not just about money, but a way to analyze choices in all areas of life.
  • Economic thinking helps in understanding decisions in contexts like dating, transportation, and even personal relationships.

Fundamental Concepts of Economics

  • Four core concepts covered: opportunity cost, sunk cost fallacy, marginal benefit/cost, and market equilibrium.
  • These concepts help break down everyday decisions and evaluate alternatives.

Opportunity Cost

  • Opportunity cost is what you give up when you choose one option over another.
  • Example: Choosing to go on a date with one person means giving up the chance to date someone else.

Sunk Cost Fallacy

  • Sunk cost fallacy is the mistake of considering past, unrecoverable costs in current decisions.
  • Example: Continuing with a bad date just because you already spent time or money on it.

Marginal Benefit and Marginal Cost

  • Marginal benefit refers to the additional gain from one more unit of a good or activity.
  • Marginal cost is the extra cost incurred from one additional unit.
  • Decisions should be made where marginal benefit equals marginal cost.

Market Equilibrium

  • Market equilibrium occurs when supply meets demand, and prices settle at a point where both buyers and sellers agree.
  • Real-life markets, like ride-sharing apps, naturally move toward equilibrium as choices and prices adjust.

Applying Economic Concepts to Daily Life

  • Economic principles can be observed in unexpected places, from dating apps to fast food deals to Uber rides.

Key Terms & Definitions

  • Opportunity cost — The value of the next best alternative forgone when a choice is made.
  • Sunk cost fallacy — The error of factoring in past, unrecoverable expenses when making new decisions.
  • Marginal benefit — The extra satisfaction or utility from consuming one more unit of something.
  • Marginal cost — The extra cost from producing or consuming one more unit of something.
  • Market equilibrium — The price point where the amount supplied equals the amount demanded.

Action Items / Next Steps

  • Analyze a part of your life using these economic concepts and identify underlying market forces.
  • Complete the assignment: observe and share how economics plays a role in non-obvious personal decisions.