Microeconomic Decision‑Makers: Firms' Costs, Revenue and Objectives
Definitions of Total Revenue (TR) and Average Revenue (AR)
Total Revenue (TR) is the total amount of money a firm receives from selling its goods or services.
Formula:
\$TR = P \times Q\$
Where:
- \$P\$ = price per unit (in £ or $)
- \$Q\$ = quantity sold (in units)
Average Revenue (AR) is the revenue earned per unit of output sold.
Formula:
\$AR = \frac{TR}{Q}\$
In perfect competition, AR equals the market price (P).
Lemonade Stand Analogy 🍋
Imagine you run a lemonade stand.
Scenario: You sell 50 cups of lemonade at £2 each.
Calculations:
- TR = 50 × £2 = £100
- AR = £100 ÷ 50 = £2 per cup
So, TR is the total money you collect (£100), and AR is the average money you get per cup (£2).
Exam Tips 📚
- Remember the core formulas: \$TR = P \times Q\$ and \$AR = \frac{TR}{Q}\$.
- In perfect competition, AR = P. Use this to simplify calculations.
- When given a graph of price and quantity, you can find TR by multiplying the price on the y‑axis by the quantity on the x‑axis.
- Check units: TR is in money (£ or $), AR is in money per unit.
- Use the analogy of a lemonade stand or a bakery to explain concepts to peers.
| Concept | Formula | Example (50 units @ £2) |
|---|
| Total Revenue (TR) | \$TR = P \times Q\$ | \$TR = 2 \times 50 = £100\$ |
| Average Revenue (AR) | \$AR = \frac{TR}{Q}\$ | \$AR = \frac{100}{50} = £2\$ |