← Economics Explained · Learning path

What is the difference between revenue and profit?

Revenue equals price times quantity for a single product. Profit subtracts relevant costs. Fixed costs do not vary with output over a specified range and horizon. Variable costs do. Marginal cost concerns the cost of an additional unit. Economic profit also recognizes opportunity costs that may not appear as accounting expenses. A sunk cost already incurred should not determine a decision about the future when it cannot be recovered.

An illustrative operating model

A producer sells 1,000 units for 20 each. Variable cost is 12 per unit and fixed cost is 5,000. Revenue is 20,000 and operating profit in this simplified model is 3,000. Break even volume is 5,000/(20 minus 12) = 625 units. If volume falls 10% with price and unit variable cost unchanged, profit becomes 2,200, a 26.7% decline. Fixed costs make profit more sensitive than sales. The example excludes tax, financing and capacity constraints.

Competition and market power

Competitive pressure depends on substitutes, entry barriers, buyer options, switching costs and potential entry as well as the number of firms. An oligopoly contains a few strategically interacting suppliers. Monopoly describes a single supplier in a defined market, but market boundaries matter. High margins can reflect market power, innovation, temporary scarcity or measurement. They do not prove a single explanation.

When private incentives miss social effects

An externality occurs when an action affects others outside the price paid by the person making the decision. Pollution can impose costs on neighbors. Learning can create benefits beyond the learner. Public goods are nonrival and nonexcludable in the relevant setting, creating financing problems. Asymmetric information can affect insurance, lending and product quality. These concepts explain why private and social outcomes may diverge.

Evaluate interventions symmetrically

Compare plausible options such as disclosure, taxation, standards, public provision or competition measures. Consider administrative capacity, unintended behavior and distributional effects. Identifying a market failure does not prove that any proposed intervention will improve the outcome. The implementation must be evaluated too.

Practice

For a delivery platform, define the relevant users and competitors. Map fees, driver compensation, customer prices, switching options and network effects. Write a measurable hypothesis, such as whether entry changes service fees, and identify alternative explanations before claiming market power.

Sources and further reading

Examples use hypothetical figures unless stated otherwise. Updated 8 October 2026.