business (trade) cycle: phases of the cycle

Economic Growth and Sustainability

Business Cycle: Phases of the Cycle

Think of the economy like a roller‑coaster 🎢. It goes up, peaks, comes down, and then starts to climb again. Each part of this ride is a phase of the business cycle.

PhaseWhat Happens?Key IndicatorsReal‑World Example
ExpansionGrowth in output, employment, and income.↑ GDP, ↓ unemployment, ↑ consumer confidence.Post‑war boom in the 1950s.
PeakThe economy reaches its highest point before turning.GDP growth slows, inflation rises.Early 2000s tech bubble burst.
Contraction (Recession)Output falls, unemployment rises.↓ GDP, ↑ unemployment, ↓ consumer spending.2008 global financial crisis.
TroughLowest point before the economy starts to recover.GDP stabilises, unemployment peaks.Early 2010s post‑crisis recovery.

  1. Expansion → Peak → Contraction → Trough → (new Expansion)

  2. Each cycle can last 5–10 years, but the length varies.

  3. Policy tools (monetary & fiscal) aim to smooth out the extremes.

Sustainability and Economic Growth

Growth is great, but if it depletes resources or harms the environment it isn’t sustainable. Think of a garden 🌱 that needs water and sunlight to grow, but if you over‑water it, the roots rot.

Key concepts:

  • Green Growth – expanding the economy while reducing environmental impact.

  • Decoupling – separating economic growth from resource use. Example: GDP ↑, CO₂ emissions ↓.

  • Use of renewable energy and energy efficiency to keep growth green.

Mathematically, sustainable growth can be expressed as:

\$g{sustainable} = \frac{\Delta Y}{Y0} - \alpha \cdot \Delta E\$

where \$Y\$ is output, \$E\$ is environmental impact, and \$\alpha\$ is the weight of sustainability.

Exam Tips for the Business Cycle

  • Use the cycle diagram to label each phase clearly.

  • Remember the order: Expansion → Peak → Contraction → Trough.

  • Link indicators to phases (e.g., GDP growth ↑ in expansion).

  • Use real‑world examples to show understanding.

  • Explain policy responses (e.g., lowering interest rates during contraction).

Tip: Practice drawing the cycle and naming indicators in your own words.