Profit maximisation and the marginal rule
Classical assumption.
Profit maximisation is the standard assumption: firms choose output where total profit (TR − TC) is highest, or equivalently where:
(Marginal revenue equals marginal cost.) Why?
- If MR > MC, producing one more unit adds more to revenue than cost → profit rises.
- If MR < MC, the last unit lost money — cut back.
- At MR = MC, profit can't be increased by adjusting output → maximum.
Limitations of pure profit maximisation:
- Hard to measure marginal revenue and cost precisely in real time.
- Short-run profit maximisation may damage long-run reputation.
- Owners and managers may differ on what to maximise.
- Ignores ethical and environmental impacts.
For this reason, many real firms pursue ALTERNATIVE objectives.
- Profit max: MR = MC.
- Real firms face measurement and reputation issues.