Interpretation of equilibrium using demand and supply schedules

Objective

Interpret equilibrium using demand and supply schedules.

1️⃣ What is Market Equilibrium?

Equilibrium is the point where the quantity demanded equals the quantity supplied. At this point, the market price is stable – no excess demand or excess supply.

Mathematically: $Q_d = Q_s$

2️⃣ Demand & Supply Schedules

Below are simple schedules for a fictional product, “Eco‑Bottles”. Prices are in £.

3️⃣ Finding the Equilibrium

1. Look for the row where $Q_d = Q_s$.
2. In our table, that happens at £1.50 where both demand and supply are 80.
3. Thus, the equilibrium price is $P^* = £1.50$ and the equilibrium quantity is $Q^* = 80$.

📌 Tip: If the table is large, use a quick scan or a calculator to match numbers.

4️⃣ Graphical Interpretation

Imagine a simple graph:

• Horizontal axis: Quantity (Q)
• Vertical axis: Price (£)
• Demand curve slopes downwards.
• Supply curve slopes upwards.

The intersection of the two curves is the equilibrium point.

🖼️ (You can sketch this on paper or use a whiteboard.)

5️⃣ Real‑World Analogy

Think of a concert ticket market:

• Demand: Fans want tickets at a price they’re willing to pay.
• Supply: The venue offers a fixed number of tickets.
• If tickets are cheap, many fans buy (high demand) but the venue might not sell all (excess supply).
• If tickets are expensive, fewer fans buy (low demand) but the venue sells all (excess supply).
• The price that balances the number of tickets sold and the number of tickets available is the equilibrium.

🔎 Why it helps: It shows how price moves to clear the market, just like in any product.

6️⃣ Examination Tips

• Always label the equilibrium point on a graph.
• Show the calculation of equilibrium price and quantity clearly.
• Use LaTeX for equations: $Q_d = Q_s$ or $P^* = £1.50$.
• Explain the economic intuition behind the numbers.
• When given a schedule, highlight the equilibrium row (e.g., with a bold or coloured background).
• Practice with different schedules to become quick at spotting equilibrium.