The foundation of every other unit. Scarcity and opportunity cost, the production possibilities curve, comparative advantage and trade, and the basics of supply, demand, and market equilibrium. Master this and the rest of AP Macro gets a lot easier.
Seven topics from the College Board CED, in order.
Topic 1.1
Introduction to Economic Thinking & Models
Scarcity, the ceteris paribus assumption, and how economists build and use models.
Topic 1.2
Resource Allocation & Economic Systems
The three basic economic questions and how command, market, and mixed economies answer them.
Topic 1.3
Production Possibilities Curve
Opportunity cost, efficiency, and growth illustrated through the PPC model.
Topic 1.4
Comparative Advantage & Trade
Absolute vs. comparative advantage, and why specialization and trade benefit both parties.
Topic 1.5
Demand
The law of demand, determinants of demand, and shifts vs. movements along the demand curve.
Topic 1.6
Supply
The law of supply, determinants of supply, and shifts vs. movements along the supply curve.
Topic 1.7
Market Equilibrium, Disequilibrium & Changes in Equilibrium
Finding equilibrium price and quantity, shortages and surpluses, and how shifts in supply or demand change equilibrium.
About Unit 1
Unit 1 is the conceptual foundation for the rest of AP Macroeconomics. You'll learn why scarcity forces every choice to have a cost — and how the production possibilities curve turns that idea into a model economists use constantly. You'll also meet the engine of every market: supply and demand, the tool that explains how prices and quantities are determined and how they change.
This unit is roughly 5–10% of the AP Macro exam and takes about 7–9 class periods. It's the smallest unit by exam weight, but every later unit assumes you can read a supply-and-demand graph and explain opportunity cost without hesitation. If you can't explain why a shift in demand is different from a movement along the demand curve here, Units 3 and 4 (the big models) will be much harder.
The College Board ties Unit 1 to three Big Ideas that recur across the whole course:
Big Idea 1
Scarcity — every choice has a cost
Big Idea 2
Markets — prices coordinate decisions
Big Idea 3
Models — economists simplify reality to explain it