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How do monopoly power and an unequal distribution of income count as market failures, and how are they measured?

Monopoly power and inequality as market failures: the welfare costs of monopoly power, factor immobility, the distinction between equity and equality, and the measurement of inequality using the Lorenz curve and Gini coefficient.

An Eduqas A520 answer to monopoly power and inequality as causes of market failure, covering the welfare costs of monopoly and the abuse of market power, factor immobility, the difference between equity and equality, and how inequality is measured with the Lorenz curve and the Gini coefficient.

Generated by Claude Opus 4.812 min answer

Reviewed by: AI editorial process; not yet individually human-reviewed

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  1. What this dot point is asking
  2. Monopoly power as a market failure
  3. Factor immobility
  4. Inequality, equity and equality
  5. Measuring inequality
  6. Examples in context
  7. Try this

What this dot point is asking

Eduqas wants you to explain why monopoly power and an unequal distribution of income are treated as market failures, identify factor immobility as a further failure, distinguish equity from equality, and measure inequality using the Lorenz curve and the Gini coefficient. This connects the theory of monopoly to the welfare and distributional concerns that justify intervention.

Monopoly power as a market failure

These welfare costs are the rationale for competition policy (regulators such as the Competition and Markets Authority) covered later in the module.

Factor immobility

Inequality, equity and equality

Measuring inequality

Examples in context

  • Big Tech. Concerns about market power in search, app stores and social media drive modern competition investigations.
  • Former industrial regions. Occupational and geographical immobility after the decline of coal and steel left persistent regional unemployment.
  • The UK Gini coefficient. Around 0.35 for disposable income, higher before taxes and benefits, illustrating how redistribution reduces measured inequality.

Try this

Q1. Explain why monopoly power is regarded as a form of market failure. [4 marks]

  • Cue. Output restricted and price raised above marginal cost (P>MCP > MC), so allocative inefficiency and a deadweight welfare loss, plus possible X-inefficiency and abuse of power.

Q2. Explain the difference between equity and equality. [3 marks]

  • Cue. Equity is fairness in distribution (a value judgement); equality is an identical distribution. A fair outcome need not be an equal one.

Exam-style practice questions

Practice questions written in the style of WJEC Eduqas exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.

Eduqas Component 2 20214 marksAn economy's poorest 20 per cent of households receive 6 per cent of total income, while the richest 20 per cent receive 44 per cent. Explain what this suggests about the distribution of income and how a Lorenz curve would represent it.
Show worked answer →

A short data-response question. Compare the income shares with an equal distribution.

Under perfect equality each 20 per cent of households would receive 20 per cent of income. Here the poorest fifth receive only 6 per cent (well below 20) and the richest fifth receive 44 per cent (well above 20), so income is unequally distributed.

On a Lorenz curve (cumulative share of income against cumulative share of households), this would show the curve bowing well below the 45-degree line of perfect equality, the further from the line the greater the inequality. Markers reward the comparison with equal shares and the correct Lorenz interpretation.

Eduqas Component 3 (micro) 202212 marksEvaluate the view that monopoly power is the most serious form of market failure.
Show worked answer →

A levels-of-response essay. Knowledge and application: explain that monopoly power leads to higher prices, restricted output, allocative inefficiency (P>MCP > MC), a deadweight welfare loss, and possible productive and X-inefficiency, and can be abused (predatory pricing, limiting choice). Draw the monopoly diagram.

Analysis: develop these welfare costs and the case for competition policy.

Evaluation: weigh against other market failures (externalities and public goods may cause larger welfare losses, for example climate change), the potential benefits of monopoly (economies of scale, innovation funded by supernormal profit), and the role of contestability and regulation in limiting the abuse. Conclude with a supported judgement, for example that monopoly power is serious but not obviously the most serious, since environmental externalities can be larger.

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