ECON1002 · Introductory Macroeconomics
The Labour Market & Unemployment
The neoclassical labour market has firms hiring up to W = VMP(L) (where VMP = MPL × output price), giving a downward-sloping labour demand against an upward-sloping supply. You then measure the labour market — the unemployment rate u = U/LF and the participation rate LF/WPOP — and classify unemployment as frictional, structural or cyclical, with the natural rate u* = frictional + structural.
It is examined as a hiring calculation (hire while VMP ≥ wage), a binding minimum-wage problem (employment from the short side, unemployment = supply − demand), and rate definitions.
What this chapter covers
- 011. Neoclassical labour market: firm hires to W = VMP(L), VMP = MPL × output price
- 022. Diminishing MPL ⇒ downward-sloping labour demand; real wage w = W/P
- 033. Stocks: Working-age pop = Labour force (employed + unemployed) + Not-in-LF
- 044. Unemployment rate u = (U/LF) × 100; participation rate = LF/WPOP
- 055. Discouraged & underemployed workers ⇒ measures understate true under-utilisation
- 066. Types of unemployment: frictional (search), structural (mismatch), cyclical (the business cycle)
- 077. Natural rate u* = frictional + structural (cyclical = 0 at u*); what shifts u*
- 088. Minimum wage above equilibrium ⇒ employment from demand, unemployment = supply − demand
Hiring to W = VMP, and a binding minimum wage
- 2 marks(a) Marginal product per extra barista: MPL = 6, 5, 4, 3, 2. VMP = MPL × $4 = 24, 20, 16, 12, 8. Hire while VMP ≥ wage $10: workers 1-4 (24, 20, 16, 12 all ≥ 10), but worker 5 has VMP 8 < 10. Hire 4.
- 1 mark(b) Free-market wage: set Nᵈ = Nˢ ⇒ 360 − 3w = 200 + w ⇒ 160 = 4w ⇒ w* = 40, with N* = 200 + 40 = 240.
- 1 markAt the binding minimum wage $50 (> 40), employment is set by the short side (demand): Nᵈ(50) = 360 − 150 = 210, while labour supplied is Nˢ(50) = 250, so unemployment = 250 − 210 = 40. Employment falls by 30 (240 → 210).
Key terms
- Value of marginal product (VMP)
- The extra revenue from one more worker: VMP = MPL × output price. A competitive firm hires labour up to the point where W = VMP, so the downward-sloping VMP curve (from diminishing MPL) is the firm's labour demand.
- Unemployment rate
- u = (number unemployed / labour force) × 100, where the labour force = employed + unemployed (people actively seeking work). It excludes those not in the labour force.
- Participation rate
- The labour force as a share of the working-age population: LF/WPOP. A fall in participation (e.g. discouraged workers leaving the labour force) can lower the measured unemployment rate even when jobs have not improved.
- Frictional, structural & cyclical unemployment
- Frictional = short-term job search and matching; structural = a mismatch of skills or location (e.g. technology displacing jobs); cyclical = unemployment from the business cycle downturn. The first two persist even at full employment.
- Natural rate of unemployment (u*)
- The unemployment that remains when the economy is at potential output: u* = frictional + structural unemployment (cyclical unemployment is zero at u*). It is influenced by benefits, minimum wages, unions and labour-market institutions.
- Binding minimum wage
- A legal wage floor set above the market-clearing wage. Employment is then determined by the short side (labour demand), and the gap between labour supplied and labour demanded at the floor is the unemployment it creates.
The Labour Market & Unemployment FAQ
How is the labour market examined in ECON1002?
As a hiring calculation (compute MPL, multiply by price to get VMP, and hire while VMP ≥ the wage), a binding minimum-wage problem (solve for the free-market wage, then read employment off demand and unemployment as supply − demand at the floor), and definitional MCQ on the unemployment and participation rates and the types of unemployment. The minimum-wage version recurs on sample and past finals.
Why does labour demand slope downward?
Because of diminishing marginal product of labour. As a firm adds workers to a fixed amount of capital, each extra worker adds less output (MPL falls), so VMP = MPL × price falls too. Since the firm hires while W = VMP, lower wages are needed to justify hiring more workers — a downward-sloping demand for labour.
Can the unemployment rate fall for a bad reason?
Yes. If discouraged workers stop searching, they leave the labour force, so both the numerator (unemployed) and the labour force shrink — and the measured unemployment rate can fall even though no jobs were created. This is why economists also watch the participation rate and broader under-utilisation (unemployment plus underemployment).
What determines the natural rate of unemployment?
The natural rate u* is the frictional plus structural unemployment that remains at potential output, with cyclical unemployment at zero. It rises with more generous or longer unemployment benefits, stronger firing protection, a higher minimum wage and skills mismatch, and falls with effective retraining and better job-matching. Cyclical policy cannot push u permanently below u*.
Exam move
Master the hiring rule as a worker-by-worker comparison: build the MPL column, multiply by output price to get VMP, then hire up to (and including) the last worker with VMP ≥ wage — never compare totals. For the minimum-wage question, drill the three-step routine: solve Nᵈ = Nˢ for the free-market wage, check the floor is binding (above it), then take employment from the demand side and unemployment as supply − demand at the floor. Memorise the rate definitions (u = U/LF, participation = LF/WPOP) and the three types of unemployment with one example each, and be ready to explain why a falling participation rate can mask a weak labour market.
