Basic Economic Concepts
This domain covers the toolkit the rest of macroeconomics uses: scarcity and opportunity cost, the production possibilities curve (PPC), comparative advantage and gains from trade, marginal analysis, and the distinction between positive and normative statements. CLEP questions here are mostly conceptual and frequently ask you to compute an opportunity cost or decide who should specialize.
Scarcity, choice, and marginal analysis
- Scarcity forces choice; every choice has an opportunity cost, the value of the next-best alternative forgone. Opportunity cost is not always a money price.
- Marginal analysis compares marginal benefit with marginal cost; sunk costs are irrelevant.
- Ceteris paribus means holding other things equal. Positive statements are testable; normative statements are value judgments.
Production possibilities curve
- The PPC shows maximum combinations of two goods with fixed resources and technology. Points on the curve are efficient, inside are inefficient, outside are unattainable.
- The absolute slope equals the opportunity cost of the good on the horizontal axis. A bowed-out PPC reflects increasing opportunity cost.
- Growth in resources or technology shifts the PPC outward; a change in the mix of goods is a movement along the curve.
Comparative advantage and trade
- Absolute advantage means producing more output with the same resources. Comparative advantage means a lower opportunity cost.
- Specialize where comparative advantage exists; the terms of trade must lie between the two countries' opportunity costs for both to gain.
- Trade can benefit both parties even when one has an absolute advantage in both goods.
Worked example
Country A can produce 100 wheat or 50 cloth; Country B can produce 60 wheat or 60 cloth. For A, 1 wheat costs 0.5 cloth; for B, 1 wheat costs 1 cloth. A has comparative advantage in wheat, B in cloth (B's cloth costs 1 wheat versus A's 2 wheat). A should specialize in wheat and B in cloth. Any terms of trade between 0.5 and 1 cloth per wheat make both better off: A gains if it receives more than 0.5 cloth per wheat, and B gains if it pays less than 1 cloth per wheat.
Traps that cost marks
- Do not confuse absolute with comparative advantage; the exam rewards opportunity-cost comparison.
- Opportunity cost is the forgone alternative, not the total money spent.
- A point inside the PPC is inefficient, not unattainable; only points outside are unattainable.
- Normative statements contain "should" and cannot be refuted by data alone.