Common economics: scarcity, markets, indicators, policy and trade
What the domain tests
This independent economics chapter reviews scarcity, choice, market behavior, macroeconomic indicators, government policy, and trade. Questions often ask you to predict a market change, distinguish types of unemployment or inflation, or identify the effect of a tax, subsidy, tariff, or interest-rate change.
Core concepts
- Scarcity and choice: Resources are limited, so every choice has an opportunity cost-the value of the next-best alternative. Producers and consumers respond to incentives; marginal analysis compares additional benefits and costs.
- Demand and supply: In the usual elementary model, holding other determinants constant, demand slopes downward and supply slopes upward. These model assumptions are not a claim that every observed market has identical behavior. A change in price causes movement along a curve; a change in income, tastes, substitute or complement prices, expectations, input costs, technology, or number of sellers shifts a curve. Equilibrium is where quantity demanded equals quantity supplied.
- Market structure and government: Competition tends to lower prices; monopoly can raise them. Externalities are spillover costs or benefits. Public goods are nonrival and nonexcludable. Government uses regulation, taxes, subsidies, and public provision to address market failures.
- Macroeconomics: GDP measures the value of final goods and services produced within the defined economy during a period; use a consistent price basis and statistical definition. Unemployment includes frictional, structural, and cyclical types. Inflation is a sustained rise in the price level, often measured by CPI. Fiscal policy uses government spending and taxes; monetary policy uses money supply and interest rates, mainly through a central bank.
- Trade: Comparative advantage explains specialization and gains from trade. Tariffs are taxes on imports; they can benefit protected producers and increase domestic prices in a standard model, while incidence and wider effects depend on responses and conditions.
Worked example
A drought destroys much of the coffee crop. What happens in the coffee market? Supply decreases, shifting left because input availability fell. At the original price, quantity demanded exceeds quantity supplied, so equilibrium price rises and equilibrium quantity falls. Demand does not shift merely because price changes; the higher price causes a decrease in quantity demanded along the demand curve.
Traps that cost marks
Do not confuse a shift in demand with a movement along demand. Do not call every price increase inflation; inflation is a broad, sustained rise in the price level. Unemployment statistics depend on official definitions of availability, active search and specified exceptions; people outside the labor force are not automatically counted as unemployed. Nominal GDP can rise from inflation alone, so real GDP is used for growth. Correlation does not prove causation, and tariffs do not only affect foreign producers.
Key terms to recognize
Opportunity cost, equilibrium, elasticity, externality, public good, fiscal policy, monetary policy, CPI, GDP, and comparative advantage.