Poverty and inequality

Edexcel International A-Level Economics· 4.3.4· 30 min read

1. Types and Measures of Poverty★★☆☆☆⏱ 8 min

Poverty is classified into two core categories for Edexcel IAL exams, each with distinct measurement frameworks used by global institutions and national governments.

📘 Definition

Absolute poverty

A condition where an individual or household cannot afford to meet basic survival needs (food, clean water, shelter, healthcare, education).

Example:

A rural household in Sub-Saharan Africa earning $1.80 p er p er so n p er d a y f a l l s b e l o w t h e W or l d B ank ab so l u t e p o v er t y l in eo f$ 2.15/day PPP.

📘 Definition

Relative poverty

A condition where an individual or household earns less than a specified percentage of a country's median income, meaning they are excluded from normal standard of living activities in their society.

Example:

A UK household with income 45% of the UK median is in relative poverty, even if their income is above the global absolute poverty line.

Causes of changes in poverty levels:
Economic growth: Inclusive growth raises average incomes, reducing absolute poverty, but may not reduce relative poverty if gains are concentrated at the top.
Education and training: Upskilling low-income workers increases their employability and wage levels, reducing long-term poverty.
Welfare benefits: Means-tested cash transfers or in-kind support directly raise household incomes for low-income groups.
Tax structure changes: Higher taxes on top earners can fund redistribution, while regressive consumption taxes may increase poverty for low-income households.
Structural change: Deindustrialisation can leave low-skilled workers unemployed, raising poverty, while services sector growth may create new low-wage jobs.
Aid: Targeted official development assistance for health, education, and microfinance can reduce poverty in low-income countries.
Civil war and conflict: Displacement, infrastructure destruction, and public service breakdown push large populations into poverty.

📐 Worked Example

Classify each scenario as absolute or relative poverty: 1) A family in India earns $2 p er p er so n p er d a y, 2) A h o u se h o l d in G er man y e a r n s 48$ 18,000 per year.

1
Step 1: Apply the absolute poverty definition: The Indian family earns $2/ d a y, b e l o w t h e$ 2.15/day PPP global threshold, so this is absolute poverty.
2
Step 2: Apply the relative poverty definition: The German household earns 48% of the national median, below the 50-60% standard for relative poverty, so this is relative poverty.

Exam tip:

When asked to distinguish between poverty types in 4-mark questions, include a relevant example for each to secure full marks.

2. Inequality Classifications and Causes★★★☆☆⏱ 8 min

Inequality refers to the unequal distribution of economic resources across a population, split into two core types: income inequality and wealth inequality.

📘 Definition

Income inequality

Unequal distribution of the annual flow of earnings (wages, profits, benefits, rent) across households or individuals in an economy.

📘 Definition

Wealth inequality

Unequal distribution of the stock of accumulated assets (property, savings, shares, land) across a population, which is typically far more concentrated than income.

Causes of inequality:
Within countries: Differences in education/skill levels, inter-sector wage gaps, wealth inheritance, gender/race discrimination, tax/benefit policies, technological change favouring high-skilled workers.
Between countries: Differences in economic growth rates, access to natural resources, colonial legacies, trade rules favouring high-income countries, FDI levels, political stability.

📐 Worked Example

Explain one reason why wealth inequality is almost always higher than income inequality in any given country.

1
Step 1: Identify the key difference between income (annual flow) and wealth (accumulated stock): Wealth can be passed between generations, while income is earned annually.
2
Step 2: Build a causal chain: Wealthy households earn returns on existing assets (interest, rent, capital gains) that are often higher than average wage growth, allowing them to accumulate more wealth over time, while low-income households have no surplus income to save and build wealth. Inheritance of assets further widens the wealth gap across generations.

Exam tip:

In 6-mark analyse questions, use multi-stage causal chains, e.g. technological change → higher demand for high-skilled workers → rising high-skilled wages → widening income inequality, to secure full KAA marks.

3. Measuring Inequality: Lorenz Curve and Gini Coefficient★★★★☆⏱ 10 min

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The two core measurement tools you are required to draw, interpret and calculate for Edexcel IAL exams are the Lorenz curve and the Gini coefficient.

📘 Definition

Lorenz curve

A graphical representation of income or wealth distribution across a population, plotting cumulative percentage of the population (ordered from poorest to richest on the x-axis) against cumulative percentage of total income/wealth (on the y-axis). The 45° line on the graph is the line of perfect equality, where every percentile of the population holds the same percentile of income/wealth. The further the Lorenz curve bows below this line, the higher the level of inequality.

G = \frac{A}{A+B}

The Gini coefficient ranges from 0 (perfect equality, all households have the same income/wealth) to 1 (perfect inequality, one household holds all income/wealth). Most countries have income Gini coefficients between 0.25 (low inequality, Nordic countries) and 0.6 (high inequality, South Africa).

📐 Worked Example

Draw a fully labelled Lorenz curve for a country with high income inequality, 2) A country has area A = 0.2 and area B = 0.3. Calculate the Gini coefficient for this country.

1
Step 1 (Draw Lorenz curve): Label x-axis 'Cumulative % of population (poorest to richest)', y-axis 'Cumulative % of total income'. Draw the 45° line labelled 'Line of perfect equality'. Draw a curve bowed significantly below the 45° line, labelled 'Lorenz curve'. Shade the area between the two lines as area A, and the area below the Lorenz curve as area B.
2
Step 2 (Calculate Gini coefficient): Substitute values into the formula: $G = 0.2/ (0.2 + 0.3) = 0.4$ , a moderate to high level of income inequality.

Exam tip:

If asked to draw a Lorenz curve in a 4-mark question, you will lose 2 marks if axes are unlabelled, and 1 mark if you do not label the line of perfect equality or Lorenz curve correctly.

4. Economic Impacts of Inequality★★★☆☆⏱ 7 min

Inequality has wide-ranging impacts on macroeconomic outcomes, which you will be asked to analyse and evaluate in extended response questions.

Enterprise and incentives: Moderate inequality creates incentives for workers to upskill and entrepreneurs to take risks, while very high inequality reduces social mobility and access to opportunities for low-income groups.
Savings: High-income households have a higher marginal propensity to save, so higher inequality can increase total national savings, but concentrated savings may be invested abroad rather than in the domestic economy.
Education: High inequality reduces access to high-quality education for low-income households, leading to lower human capital accumulation and slower long-term growth.
Migration: High inequality in low-income countries can drive skilled workers to emigrate to higher-income, more equal countries, leading to brain drain.
Life expectancy: High inequality correlates with lower average life expectancy, as low-income groups have limited access to healthcare and healthy living conditions.
Free market impact: Free markets produce unequal outcomes based on marginal product of labour and capital, leading to higher inequality than planned economies, but may also deliver higher growth that reduces absolute poverty over time.

📐 Worked Example

Analyse the impact of rising income inequality on long-run economic growth in a low-income country.

1
Step 1: First causal channel: Rising inequality reduces access to education for low-income households, leading to a less skilled workforce in the long run.
2
Step 2: Extend the chain: Lower human capital reduces labour productivity, which reduces potential output growth and limits the country's ability to move up global value chains.
3
Step 3: Second channel: High inequality may lead to social unrest and political instability, which reduces domestic and foreign investment, further slowing growth.

Exam tip:

When evaluating inequality impacts in 20-mark essays, include counterpoints: moderate inequality can boost incentives and growth, so impacts depend on inequality level, country development stage, and existing social safety nets.

5. Common Pitfalls

Wrong move:

Confusing absolute and relative poverty, stating that relative poverty is the same across all countries.

Why:

Relative poverty is measured against national median income, so it depends on the average income level of the country, unlike the global absolute poverty threshold.

Correct move:

Always specify the measurement framework when discussing poverty, and use relevant examples for each type.

Wrong move:

Drawing the Lorenz curve with population ordered from richest to poorest on the x-axis.

Why:

The Lorenz curve requires cumulative population to be ordered from poorest to richest to correctly show unequal distribution.

Correct move:

Always label the x-axis 'Cumulative % of population (poorest to richest)' and plot the curve starting at (0,0) and ending at (100,100).

Wrong move:

Calculating the Gini coefficient as $B / (A + B)$ instead of $A / (A + B)$ .

Why:

The Gini coefficient measures the share of the total area under the line of perfect equality that is between the line and the Lorenz curve, so area A is the numerator.

Correct move:

Memorise the formula $G = A / (A + B)$ , and double-check your calculation in exam questions to avoid arithmetic errors.

Wrong move:

Confusing income and wealth inequality, using Gini coefficients for wealth when discussing annual earnings.

Why:

Wealth is a stock of accumulated assets, while income is an annual flow, so their Gini coefficients are not comparable.

Correct move:

Explicitly state whether you are discussing income or wealth inequality, and note that wealth Gini coefficients are almost always higher than income Gini coefficients for the same country.

Wrong move:

Stating that economic growth always reduces inequality.

Why:

Growth may be concentrated at the top of the income distribution (e.g. growth driven by tech sectors that only benefit high-skilled workers), leading to rising inequality even as absolute poverty falls.

Correct move:

Distinguish between inclusive growth (which reduces inequality) and exclusive growth (which increases inequality), and note that the impact of growth on inequality depends on how growth gains are distributed.

6. Quick Reference Cheatsheet

Concept	Key Definition	Measure/Formula	Exam Reminder
Absolute Poverty	Cannot afford basic survival needs	World Bank $2.15/day PPP	Linked to global threshold, not national income
Relative Poverty	Below 50-60% of national median income	% of national median household income	Varies by country, reflects social exclusion
Lorenz Curve	Graph of income/wealth distribution	X: cumulative % population (poorest→richest), Y: cumulative % income	45° line = perfect equality, further curve = more inequality
Gini Coefficient	Numerical measure of inequality	$G = A / (A + B)$ , range 0→1	Higher G = higher inequality; 0 = perfect equality, 1 = perfect inequality
Income Inequality	Unequal distribution of annual earnings	Income Gini coefficient	Typically 0.25-0.6 across countries
Wealth Inequality	Unequal distribution of accumulated assets	Wealth Gini coefficient	Almost always higher than income inequality

7. Frequently Asked

What is the difference between absolute and relative poverty?

Absolute poverty is measured against a fixed global threshold ($2.15/day PPP) for basic needs, so it is comparable across countries. Relative poverty is measured against 50-60% of a country's median income, so it varies by national income levels and reflects social exclusion rather than just survival needs.

Does a higher Gini coefficient mean more or less inequality?

A higher Gini coefficient (closer to 1) means greater inequality. A Gini of 0 means perfect equality (all households have the same income/wealth), while a Gini of 1 means perfect inequality (one household holds all income/wealth).

Why is wealth inequality almost always higher than income inequality?

Wealth is a stock of accumulated assets that can be passed across generations, while income is an annual flow. Wealthy households earn returns on existing assets that often outpace average wage growth, allowing them to accumulate more wealth over time, while low-income households have no surplus income to save.

Going deeper

What's Next

Now that you have mastered poverty and inequality measurement and analysis, you can move on to the next Unit 4 topics focused on policy responses to these issues, and wider development strategies. You will apply your understanding of inequality trends to evaluate the effectiveness of government redistribution policies, and connect inequality outcomes to broader global development metrics. Make sure you practice drawing Lorenz curves and calculating Gini coefficients using past paper data, and practice constructing causal chains for 6-mark analyse questions to secure high KAA marks in extended responses.