Revenue and profit

Welcome to the World of Revenue and Profit!

Ever wondered why some businesses stay open even when they seem to be just "getting by," while others close despite making thousands of pounds? It all comes down to how economists look at revenue and profit. In this guide, we will break down these vital concepts so you can calculate them with confidence and understand the "why" behind business survival.

Don't worry if this seems a bit mathematical at first—we’ll take it one step at a time with simple examples you’d see in everyday life!

1. Understanding Revenue: The Money Coming In

Revenue (sometimes called turnover) is the total amount of money a firm receives from selling its goods or services. It is not the same as profit, because we haven’t taken away the costs yet!

Total Revenue (TR)

This is the total amount of money a firm makes from sales.

The Formula: \( \text{Total Revenue} = \text{Price} \times \text{Quantity} \)

Example: If you sell 100 t-shirts for £20 each, your TR is: \( 20 \times 100 = \$2,000 \).

Average Revenue (AR)

This is how much money is made per unit sold. In most cases, Average Revenue is simply the Price of the product.

The Formula: \( \text{Average Revenue} = \frac{\text{Total Revenue}}{\text{Quantity}} \)

Quick Tip: Think of "Average" as "Price." If you sold 10 t-shirts for £100 total, the average is £10—which was the price you charged!

Marginal Revenue (MR)

This is the extra money a firm gets from selling one more unit of a product. This is a "marginal" concept, meaning we are looking at the "edge" or the very last item sold.

The Formula: \( \text{Marginal Revenue} = \frac{\Delta \text{Total Revenue}}{\Delta \text{Quantity}} \) (where \( \Delta \) means "change in")

Quick Review: The Revenue Trio

• Total Revenue (TR): The whole "pot" of money.
• Average Revenue (AR): The price per item.
• Marginal Revenue (MR): The extra money from the next item sold.

Key Takeaway: Revenue is just the "top line" figure. It tells us about sales volume, but it doesn't tell us if the business is actually successful or sustainable yet.

2. Profit and Loss: The Bottom Line

Profit is what remains of the revenue after all Total Costs (TC) have been paid. If costs are higher than revenue, the firm makes a Loss.

The Formula: \( \text{Profit} = \text{Total Revenue} - \text{Total Costs} \)

Memory Aid: The "Leftover" Rule
Imagine a pizza. Revenue is the whole pizza. Costs are the slices you have to give to your landlord, your staff, and your suppliers. Profit is whatever slices you have left for yourself!

Did you know? Firms don't always try to make the most profit possible. Sometimes they focus on revenue maximisation to push out competitors or sales volume to gain market share!

3. The Three Types of Profit (The Economist's View)

This is where Economics gets different from standard Accounting. Economists don't just look at money paid out; they look at Opportunity Cost (the value of the next best thing you gave up).

Accounting Profit

This is what you see in a bank statement. It is simply \( \text{Revenue} - \text{Explicit Costs} \) (money actually paid out, like rent and wages).

Normal Profit

This is the "break-even" point for an economist. It occurs when Total Revenue exactly covers Total Costs, including the opportunity cost of the entrepreneur’s time and capital.

• When TR = TC: The firm is making Normal Profit.
• It is the minimum profit needed to keep a firm in its current line of business.

Supernormal Profit (also called Abnormal Profit)

This is the "extra" profit! It is any profit made over and above normal profit.

• When TR > TC: The firm is making Supernormal Profit.
• This extra profit usually attracts new firms into the industry because it looks so lucrative!

Analogy: The Career Choice

Imagine you quit a job paying £30,000 a year to start a coffee shop.
• In your first year, your shop makes £30,000 profit after paying for beans and rent.
• An Accountant says: "Great! You made £30,000 profit!"
• An Economist says: "You made Normal Profit. You haven't gained anything extra compared to your old job, but you've covered your costs and your time."
• If your shop made £40,000, the Economist would say you made £10,000 Supernormal Profit.

Key Takeaway: Normal profit is like "staying level," while supernormal profit is "getting ahead."

4. Summary of Key Formulas and Concepts

Before you move on, make sure you are comfortable with these "quick hits":

Common Mistakes to Avoid:
1. Confusing Revenue with Profit: Never say "The firm's profit was £5,000" if you actually mean they sold £5,000 worth of goods. Always subtract the costs!
2. Forgetting Opportunity Cost: In Economics exams, "Total Cost" almost always includes the opportunity cost. If the question mentions "Normal Profit," it means the firm is technically "breaking even" in economic terms.

Quick Review Box

TR: P x Q
AR: TR / Q (Usually the Price)
MR: Change in TR / Change in Q
Normal Profit: TR = TC (Firm stays in business)
Supernormal Profit: TR > TC (Firm is doing better than its next best alternative)

Don't worry if the distinction between accounting and economic profit feels a bit strange—most students find it tricky at first. Just remember that economists always ask: "What else could the business owner be doing with their time and money?"