Business economics and market structures - Eduqas A-Level Economics (A520) overview

The business-economics-and-market-structures module of Eduqas A-Level Economics (specification A520) is the theory of the firm. It takes the cost and revenue curves and uses them to model how firms behave in each of the four market structures, and how labour markets set wages. This page maps the specification statements and how they are examined.

The statements in this module

Costs, revenues and profit

Fixed and variable costs, the marginal, average and total cost and revenue curves, the law of diminishing returns, normal and supernormal profit, and the profit-maximising condition that marginal cost equals marginal revenue.

Economies of scale and business growth

Internal and external economies of scale, the long-run average cost curve and the minimum efficient scale, the causes of diseconomies of scale, organic versus integrated growth (horizontal, vertical and conglomerate), and the divorce of ownership from control.

Perfect competition and monopolistic competition

Their assumptions and characteristics, short-run and long-run equilibrium, the role of free entry and exit in competing away supernormal profit, and the efficiency of each structure.

Oligopoly and monopoly

Concentration and barriers to entry, interdependence and collusion, the kinked demand curve and game theory, the profit-maximising monopoly, price discrimination, and the costs and benefits of monopoly power.

The labour market

The derived demand for and supply of labour, wage determination in a competitive market, wage differentials, monopsony and trade unions, and the effects of a national minimum wage.

How this module is examined

Eduqas Economics is a two-year linear course with three papers at the end. This theory of the firm is sampled across all of them: Component 1 uses multiple-choice and short structured questions, Component 2 uses data-response calculations, and Section A of Component 3 offers a choice of microeconomics essays marked by levels of response. Higher-mark questions reward accurate diagrams and balanced evaluation.

How to study this module

1. Draw every market-structure diagram from memory. Perfect competition (short and long run), monopolistic competition, oligopoly and monopoly, with the cost and revenue curves correctly placed.
2. Master the profit-maximising rule. $MC = MR$ pins down output in every structure; layer the average-cost and average-revenue curves on top to read off profit.
3. Compare efficiency systematically. Allocative, productive and dynamic efficiency across structures is the spine of the evaluation.
4. Use real examples. Supermarkets and energy (oligopoly), commodity markets (perfect competition), the NHS (monopsony) and the National Living Wage make application marks easy.

Work through the statements

Each statement has its own focused answer page with worked exam questions and cross-links: costs, revenues and profit; economies of scale and business growth; perfect competition and monopolistic competition; oligopoly and monopoly; and the labour market.

For the official specification

Eduqas publishes the full specification (A520), past papers and mark schemes at eduqas.co.uk. Always revise from the current specification and Eduqas's own past papers, because the multiple-choice format of Component 1 and the levels-of-response mark schemes are board-specific.