Inequality (Poverty and Inequality)

The first mark examiners look for is a clean distinction between income and wealth.

Income is a flow: it is money received over a period of time — wages and salaries, interest, dividends, rent, profit and state benefits. We measure it per week, per month or per year.

Wealth is a stock: it is the value of the assets a person owns at a single point in time — property and land, shares and bonds, pension pots, savings and physical possessions, minus any debts. We measure it on a given date.

A simple test: if the units include "per year" you are talking about income (a flow); if it is a value "as at 31 December" you are talking about wealth (a stock).

Why the distinction matters. The two are linked but not the same:

• A high income lets a person save and buy assets, which builds wealth over time.
• A large stock of wealth generates an income (rent, dividends, interest) even if the owner does no work.

Wealth inequality is almost always larger than income inequality. Wealth accumulates — savings, rising asset prices and, crucially, inheritance pass wealth between generations, concentrating it at the top. A country can have a moderately unequal income distribution but a very unequal wealth distribution, so a policy question about "inequality" should always ask which one.

The Lorenz curve is the standard diagram for showing how equally (or unequally) income is distributed within a country.

How it is built. Line the population up from poorest to richest, then plot:

• the cumulative % of the population on the horizontal axis (0 → 100), against
• the cumulative % of total income they receive on the vertical axis (0 → 100).

The line of perfect equality is the 45° diagonal from corner to corner: if everyone earned exactly the same, the poorest 20% of people would earn 20% of income, the poorest 50% would earn 50%, and so on — every point lies on the diagonal.

Because the poorest people earn less than an equal share, the real Lorenz curve bows below the diagonal: the poorest 50% of the population might receive only, say, 20% of total income (point on the curve well below the 45° line).

Reading the diagram. In the diagram the green diagonal is the line of perfect equality and the blue curve is the Lorenz curve. The guide lines show that the poorest 50% of the population receive only about 20% of income — the curve sits well below the equal-share point of 50%.

The golden rule: the further the Lorenz curve bows away from (below) the diagonal, the greater the inequality. A curve lying on the diagonal means perfect equality; a curve that hugs the axes (bottom then right) means near-perfect inequality (one person has all the income).

The Lorenz curve shows inequality; the Gini coefficient turns it into a single number so distributions can be compared and tracked over time.

Using the areas on the Lorenz diagram, define:

• Area A = the area between the line of perfect equality and the Lorenz curve (the red shaded gap).
• Area B = the area below the Lorenz curve.

The Gini coefficient is:

$\text{Gini} = \frac{A}{A + B}$

where A + B is the whole triangular area beneath the line of perfect equality.

Interpreting the number. Because A is a fraction of the whole triangle, the Gini always lies between 0 and 1:

• Gini = 0 → the Lorenz curve is the diagonal, so area A = 0 → perfect equality (everyone has the same income).
• Gini = 1 → the Lorenz curve hugs the axes, so area B = 0 and A is the whole triangle → perfect inequality (one person has all the income).
• The closer to 1, the more unequal the distribution. (Some sources multiply by 100 and quote the Gini index from 0 to 100 — same idea, different scale.)

Worked interpretation. Suppose Country X has a Gini of 0.30 and Country Y a Gini of 0.48. Country Y is the more unequal: its Lorenz curve bows further from the diagonal, so area A is a larger share of the triangle. If Country X's Gini then rose from 0.30 to 0.35, income inequality in X has increased over that period.

Why economists like it. One comparable number lets you: rank countries, watch a country's inequality rise or fall over time, and judge whether a policy (a more progressive tax, say) has actually narrowed the gap. Its limitation: a single number hides where in the distribution the inequality sits — two very different distributions can share the same Gini.

Inequality has many causes, and a strong answer names several and explains the mechanism for each rather than just listing them.

1. Differences in wages and skills. Skilled, educated and in-demand workers command higher wages than low-skilled workers, so labour income is unequal. Occupations with strong bargaining power or scarce talent (surgeons, top managers) earn multiples of the minimum wage.

2. Ownership of wealth and capital. Those who own assets (property, shares, businesses) receive income from wealth (rent, dividends, capital gains) on top of any wages — so wealth inequality feeds income inequality.

3. Inheritance. Wealth passed between generations concentrates assets at the top and gives some people a head start regardless of effort — a major reason wealth is more unequal than income.

4. Education. Unequal access to good schooling and higher education creates unequal human capital, locking in future wage gaps and reducing social mobility.

5. Discrimination. Unequal treatment by gender, ethnicity, age or background can push some groups into lower-paid work or block promotion, widening the gap for reasons unrelated to productivity.

6. The tax-and-benefit system. Progressive taxes and transfer payments (benefits, pensions) reduce inequality; a shift towards regressive or indirect taxes, or benefit cuts, can increase it. The system is a cause of the final distribution, not just a cure.

7. Globalisation. Trade and offshoring can raise incomes for skilled workers and capital owners while depressing wages for low-skilled workers in competition with cheaper labour abroad — widening inequality within a country even as it may narrow it between countries.

8. Technology. Skill-biased technological change and automation raise demand (and pay) for high-skilled workers while displacing routine, lower-skilled jobs, pulling the two ends of the distribution apart.

Whether inequality is a problem is a judgement, and the best answers weigh both sides — this is the heart of the equity vs efficiency debate.

The case that some inequality is necessary (the efficiency argument).

• Incentives. The prospect of higher pay encourages people to work harder, gain skills, take risks and start businesses — differences in reward drive effort and enterprise.
• Signals. Higher wages in some occupations signal where labour is scarce, helping the market allocate workers efficiently.
• A completely equal distribution could blunt incentives and reduce the total size of the economy — so some inequality can raise efficiency and growth.

The case against high inequality (the costs).

• Lower social mobility and wasted potential: talented people from poor backgrounds may never access education or capital, so the economy loses their productivity.
• Weaker demand: poorer households spend a larger share of income (a higher marginal propensity to consume), so a very unequal distribution can drag on aggregate demand.
• Social and health costs: high inequality is linked to worse health, higher crime and reduced social cohesion — real economic costs.
• Relative poverty: even in a rich country, those far below the median can be excluded from a normal standard of living.

The trade-off. Reducing inequality (through taxes and benefits) can improve equity/fairness but may weaken incentives and efficiency (e.g. high top tax rates could discourage effort or encourage tax avoidance). The policy question is therefore how much redistribution, and by what means — not simply "more" or "less".

Governments have a toolkit for reducing inequality; each policy has benefits and drawbacks you should evaluate.

1. Progressive taxation. A tax where the average rate rises with income (higher earners pay a larger proportion). It directly narrows the post-tax income gap and funds redistribution.

• Trade-off: very high top rates may weaken work incentives, encourage tax avoidance/evasion or a "brain drain" of high earners, so revenue and growth could suffer.

2. Transfer payments (benefits and pensions). Cash transfers — unemployment benefit, state pensions, child benefit, in-work benefits — raise the incomes of the poorest, lifting the bottom of the Lorenz curve.

• Trade-off: generous benefits are costly and, if poorly designed, can create a welfare trap where people are little better off in low-paid work than on benefits (a disincentive).

3. Education and training. Investing in schooling, skills and healthcare raises the human capital of poorer groups, improving their long-run earning power and social mobility.

• Trade-off: the effect is slow (a generation) and expensive, though it is the most likely to reduce inequality and boost growth.

4. National minimum / living wage. A legal wage floor raises the pay of the lowest-paid workers, narrowing the wage gap.

• Trade-off: if set above the market wage, classical theory predicts it could cause some unemployment among low-skilled workers; the size of any job loss depends on the elasticity of demand for labour and is debated empirically.

Evaluating the package. Judgement points that lift an answer:

• Equity vs efficiency: how far does the policy trade fairness against incentives?
• Time frame: taxes/benefits act fast but treat symptoms; education tackles root causes but is slow.
• Government failure: administration costs, information gaps and unintended effects (welfare traps, avoidance) may blunt the policy.
• Income vs wealth: most tools target income; reducing entrenched wealth inequality may need inheritance or capital taxes.

The best conclusion is usually a balanced mix — combining fast-acting taxes and transfers with slower, growth-friendly investment in education — judged against the government's equity objectives and its budget.