Economics
What this domain tests
Economics tests scarcity, choice, markets, macroeconomics, trade, and personal finance. Expect graphs, cause-and-effect reasoning, and policy analysis using models rather than slogans.
Core rules
- Scarcity forces trade-offs. Opportunity cost is the value of the best forgone alternative, including time and noncash costs.
- Marginal thinking. Decisions compare marginal benefit and marginal cost, not totals.
- Demand and supply shift for specific reasons. Income, tastes, substitutes, expectations, and number of buyers shift demand; input costs, technology, taxes, and expectations shift supply. Price changes cause movements along a curve, not shifts.
- Elasticity changes incidence. When demand is inelastic, consumers bear more of a tax; when demand is elastic, producers bear more.
- Macro measures need care. GDP counts final output; real values adjust for inflation; unemployment excludes discouraged workers.
- Policy has lags. Monetary and fiscal policy affect output and prices with delay and trade-offs.
Worked example
Prompt: A city imposes a binding rent ceiling below the market rent. What happens? Reasoning: at the ceiling, quantity demanded exceeds quantity supplied, creating a shortage. Existing units may be rationed by waiting lists or side payments, and maintenance may decline because landlords cannot recover costs. The effect is not simply cheaper housing for all; some tenants gain, others lose access, and the shortage grows over time as supply adjusts.
Traps
Confusing a shift with a movement along a curve; mixing nominal and real values; treating a budget deficit and the national debt as identical; assuming correlation proves causation; and ignoring ceteris paribus when predicting a price change.