AP Microeconomics Unit 5: Factor Markets
Study labor demand/supply, wages, monopsony, capital markets with exam-format practice and rubric-based scoring.
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Inside This Unit: The Full Breakdown
This unit examines factor markets — the markets for labor, capital, and land. Students learn how firms determine how many workers to hire, how wages are determined, and how factor market outcomes relate to income distribution.
Why it matters
Factor markets connect production decisions to income distribution — one of the most policy-relevant topics in economics. The AP Micro exam consistently tests marginal revenue product, labor market equilibrium, and monopsony.
Key concepts
- The demand for factors of production is derived from the demand for the products they help create.
- Marginal revenue product (MRP) — the additional revenue from hiring one more unit of a factor — determines how much of that factor a firm will employ.
- In a competitive labor market, firms hire workers until the wage equals MRP; the wage is determined by market supply and demand for labor.
- A monopsony — a single buyer of labor — pays lower wages and hires fewer workers than a competitive labor market would.
Derived Demand and Marginal Revenue Product
The demand for factors like labor is derived demand — firms hire workers not for their own sake but because workers produce output that generates revenue. Marginal revenue product (MRP) is calculated as marginal product (MP) multiplied by marginal revenue (MR). A profit-maximizing firm hires additional units of a factor as long as MRP exceeds the factor price. The MRP curve is the firm's demand curve for the factor. Anything that increases MP (better technology, more complementary inputs) or MR (higher product price, more market power) shifts the MRP curve and increases factor demand.
Competitive Labor Markets
In a competitive labor market, many firms compete for workers and many workers offer their labor. The market wage is determined by the intersection of labor supply and labor demand (the sum of all firms' MRP curves). Each firm is a wage taker and hires workers until MRP equals the market wage. Changes in labor supply (due to demographics, immigration, or preferences) or labor demand (due to productivity changes or product demand shifts) change the equilibrium wage and employment level. Wage differentials between occupations reflect differences in skill requirements, working conditions, and the relative supply of qualified workers.
Monopsony and Market Power in Factor Markets
A monopsony exists when a single firm is the dominant buyer of labor in a market. Because the monopsonist must raise wages to attract additional workers — and pays the higher wage to all workers — its marginal factor cost (MFC) exceeds the wage (supply curve). The monopsonist maximizes profit by hiring where MRP equals MFC, but pays the wage on the supply curve for that quantity — resulting in lower wages and less employment than the competitive outcome. A minimum wage set between the monopsony wage and the competitive wage can actually increase both wages AND employment, which is counterintuitive but important for the AP exam.
AP exam tip
For factor market questions, always distinguish between the factor MARKET diagram (supply and demand for labor) and the individual FIRM diagram (MRP and wage or MFC). On the AP exam, both are often required in the same question.
Connections to other units
- Unit 2: MRP depends on marginal product (from production functions) and marginal revenue (from the product market structure).
- Unit 3: Firms with monopoly power in product markets have different MRP curves than competitive firms.
- Unit 5: Government interventions like minimum wage and unions are evaluated using the factor market framework.
