business (trade) cycle: phases of the cycle

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.

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:

$g_{sustainable} = \frac{\Delta Y}{Y_0} - \alpha \cdot \Delta E$

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.