Profit maximisation and the MC equals MR rule, and alternative objectives including revenue maximisation, sales maximisation, satisficing and survival.

What this dot point is asking

Edexcel wants you to explain profit maximisation and the marginal-cost-equals-marginal-revenue rule, and explain alternative business objectives and why firms might pursue them.

Profit maximisation

Profit matters because it rewards risk, funds investment (retained profit), signals where to allocate resources and provides a return to shareholders. Supernormal profit also attracts entry in contestable markets, eroding it over time.

Normal versus supernormal profit

It helps to distinguish two levels of profit. Normal profit is the minimum return needed to keep a firm in its current line of business; it is treated as a cost (the opportunity cost of the entrepreneur's capital and effort) and is earned when average cost equals average revenue. Supernormal (abnormal) profit is any profit above this, earned when $AR > AC$ at the profit-maximising output. The distinction drives entry and exit: supernormal profit signals that a market is attractive and, where barriers to entry are low, draws in new firms whose output competes the profit away back towards normal. This is why a profit-maximising firm in a competitive market may earn only normal profit in the long run, while one with strong barriers (a patent, a network effect) can sustain supernormal profit.

Alternative objectives

• Satisficing means earning enough profit to keep shareholders content while managers pursue other goals, a direct response to the principal-agent problem (Simon's bounded rationality).
• Survival becomes the priority in a recession or for a new entrant, where the firm accepts losses to stay in the market.
• Ethical and social objectives (fair trade, low emissions, corporate social responsibility) can build reputation and long-run profit, though they may raise costs in the short run.

At the profit-maximising output the firm charges the highest price; at the revenue-maximising output (lower price, higher quantity) it sacrifices some profit for market share.

The divorce of ownership and control

The reason firms may not profit-maximise is the principal-agent problem: shareholders (principals) own the firm but managers (agents) run it day to day, and the two have different goals. Managers may prefer revenue or sales growth because their pay, status and job security are often tied to firm size rather than profit, and shareholders cannot perfectly monitor them (asymmetric information). This explains satisficing, where managers earn just enough profit to avoid shareholder revolt while pursuing their own aims. Devices such as performance-related pay, share options and the threat of takeover are designed to realign managers with the profit goal, which is why behaviour may still approximate profit maximisation in the long run.

Evaluating whether firms really profit-maximise

Weigh the case both ways. Magnitude of the divergence: in highly competitive or contestable markets, the discipline of entry and the need to fund investment force firms close to profit maximisation, so the divergence is small; in concentrated markets with weak shareholder oversight it can be large. Time horizon: what looks like sales maximisation in the short run (Amazon under-pricing to win share) can be long-run profit maximisation once a dominant position is built, so the objective depends on the period chosen. Ceteris paribus and measurement: the $MC = MR$ rule assumes firms can actually measure marginal cost and marginal revenue, but most use cost-plus pricing because they lack precise data, so profit maximisation is a useful theoretical benchmark rather than a literal description of behaviour. A judgement should note that long-run survival pressure pulls most firms towards profit even when their stated objective differs.

Examples in context

• Amazon's early years. Amazon long prioritised revenue and market-share growth over profit, posting thin or negative net margins through the 2000s, a classic real-world departure from short-run profit maximisation that arguably served long-run profit.
• Tesco loss leaders. Sales-maximising pricing on staples such as milk and bread draws customers who then buy higher-margin goods, raising overall store profit.
• Patagonia. An explicit ethical and environmental objective, including pledging profits to environmental causes, that builds brand loyalty and long-run profit.
• Airlines in 2020. Many carriers, such as British Airways and easyJet, switched to a survival objective during the pandemic, raising emergency finance and accepting heavy losses to avoid collapse.
• Start-ups and venture funding. Loss-making scale-ups deliberately satisfice or pursue growth, relying on investor patience until they reach the scale at which profit maximisation becomes feasible.
• Supermarket price wars and survival pricing. When the German discounters Aldi and Lidl expanded their UK market share past a combined 15 per cent in the 2020s, the established chains cut prices to defend volume rather than maximise short-run profit. The chain of analysis: losing share to discounters threatens long-run viability, so firms accept lower margins now (a survival and market-share objective) to protect their long-run profit-maximising position. It shows the stated objective shifting with the competitive threat rather than being fixed.
• John Lewis Partnership. An employee-owned model with an explicit objective of partner wellbeing alongside profit, illustrating how the ownership structure itself shapes the objective: with no external shareholders demanding maximum dividends, the firm can weight staff and customer outcomes more heavily, though it still needs profit to fund investment and reward partners.

Try this

Q1. State the output rule for profit maximisation and explain why. [3 marks]

• Cue. $MC = MR$; below it an extra unit adds more revenue than cost, beyond it the reverse, so the profit gap is largest at $MC = MR$.

Q2. Explain why a manager might pursue revenue maximisation rather than profit maximisation. [4 marks]

• Cue. The principal-agent problem: managers' pay or status may be tied to sales or revenue rather than shareholder profit.