Distribution of income and wealth in Australia (HSC Economics Topic 3)

A 6 mark response needs the diagram and definitions, then a trend analysis distinguishing income from wealth.

Lorenz curve

Plots cumulative income share (vertical axis) against cumulative population share ranked poorest to richest (horizontal axis). The 45-degree line is perfect equality; the actual curve bows below it, and the further it bows the greater the inequality.

Gini coefficient

The area between the line of equality and the Lorenz curve divided by the total area below the line of equality, on a scale from 0 (perfect equality) to 1 (perfect inequality). Australia's after-tax income Gini is around 0.32, in the middle of the OECD.

Income trend

Income inequality has been relatively stable over the past two decades (Gini around 0.32 to 0.34), unlike the rising trend in the United States.

Wealth trend

Wealth is far more unequal (the top 20 percent hold around 60 percent of wealth versus around 40 percent of income) and wealth inequality has risen, driven by housing price gains that benefit existing owners over renters, widening intergenerational inequality.

Markers reward (1) a correctly drawn Lorenz curve, (2) the Gini definition and Australia's value, (3) the income-versus-wealth distinction, (4) a specific trend with data.

A 5 mark response covers both economic and social impacts, with a balanced view.

Economic, negative

Lower-income households have a higher marginal propensity to consume, so high inequality can reduce aggregate demand growth. High inequality also reduces social mobility and human capital investment, dragging on long-run growth (OECD).

Economic, positive (in moderation)

Returns to education, effort and entrepreneurship provide incentives for skill acquisition, risk-taking and innovation.

Social

Relative poverty affects around 13 percent of Australians; there are health gaps (a life-expectancy gap of around 6 years between the highest and lowest socioeconomic quintiles), education gaps, and housing stress among low-income renters.

Redistribution

Australia's progressive tax-and-transfer system is among the most redistributive in the OECD, cutting the Gini from around 0.45 (market income) to around 0.32 (disposable income).

Markers reward (1) at least one economic and one social impact, (2) the MPC and aggregate-demand link, (3) recognition that some inequality provides incentives, (4) the role of the tax-transfer system.

A 4-mark "distinguish and exemplify" needs both definitions and a fitting Australian example each.

Income (2 marks: 1 definition, 1 example). Income is a flow - payments received over a period of time (wages, salaries, transfers, dividends, interest, rent). Example: a full-time graduate earning a salary from employment.

Wealth (2 marks: 1 definition, 1 example). Wealth is a stock - the value of assets owned less liabilities, measured at a point in time (housing, superannuation, shares). Example: a retiree who owns their home outright and holds a large superannuation balance but has low current income.

Full marks require BOTH concepts defined as flow versus stock and a specific (not generic) Australian example for each.

A 5-mark "explain" needs the construction method plus the comparison rule.

Construction (about 3 marks). Households are ranked from lowest to highest income; the horizontal axis plots cumulative population share (0 to 100 percent) and the vertical axis plots the cumulative share of income those households hold. The 45 degree line is perfect equality; the actual curve is plotted by joining the cumulative income shares at each population share (e.g. plotting the point where the poorest 20 percent of households hold 7 percent of income).

Comparison rule (about 2 marks). The further the curve bows away from (below) the line of equality, the greater the inequality; comparing two countries' curves on the same axes, whichever curve is closer to the diagonal is the more equal distribution. This is the visual basis for the Gini coefficient, which converts the bow into a single number.

Markers reward the correct axis definitions, the ranking rule (poorest to richest), and the "further from the diagonal = more unequal" comparison principle.

A 5-mark "calculate and explain" rewards the correct calculation with working, plus an explanation that goes beyond restating the number.

Calculate (about 2 marks).

The highest-earning quintile's share of income is about 5.6 times the lowest-earning quintile's share.

Explain (about 3 marks). A ratio around 5.6 indicates a moderate degree of income inequality: substantially unequal in absolute terms, but far less extreme than countries with weak redistribution (e.g. the United States, Gini about 0.41) because Australia's progressive tax and means-tested transfer system compresses the gap between market income and disposable income (cutting the Gini from about 0.45 to about 0.32). The ratio also understates the full picture because it ignores wealth, which is even more concentrated (the top quintile holds about 60 percent of wealth).

Marking spine: correct ratio with working shown (2), the ratio linked to a judgement about the DEGREE of inequality (2), and a caveat distinguishing income from the more unequal wealth picture (1). A bare number with no interpretation caps at 2.

A 6-mark "analyse... why" needs the measurement tools correctly applied AND a causal explanation, not just a repeated definition.

Apply the tools (about 2 marks). A Lorenz curve for Australian wealth bows further from the line of equality than the income Lorenz curve; correspondingly, the wealth Gini (unofficial estimates around 0.6, based on Productivity Commission wealth-quintile data) is well above the income Gini of about 0.32.

Explain the causal difference (about 4 marks). Income is a FLOW that is refreshed every pay cycle and compressed at the bottom by minimum wages, awards and means-tested transfers (JobSeeker, Family Tax Benefit); the tax-transfer system directly targets income. Wealth is a STOCK accumulated over a lifetime, concentrated by (i) compounding - existing asset owners benefit from capital gains on housing and shares that non-owners cannot access, (ii) housing specifically, where price growth over decades has widened the gap between owners and renters, and (iii) intergenerational transfer (inheritance), which passes accumulated wealth to already-advantaged households. Because policy (income tax, transfers) targets the flow, not the stock, wealth inequality is structurally harder to correct and has continued to widen even while income inequality has stayed broadly stable.

Marking spine: correct Lorenz/Gini comparison (2), at least two distinct mechanisms (compounding/asset growth, policy asymmetry, inheritance) explicitly explaining the GAP (3), and a link back to the measurement tools (1). A list of facts about wealth with no explicit "why more unequal than income" reasoning stays mid-band.

A 6-mark "identify and explain" needs three DISTINCT sources with a mechanism, not just three labels.

Employment status and hours worked (2 marks)

Households with no employed adult, or only part-time/casual work, receive far less income than dual-earner, full-time households; the rise of part-time and casual employment (especially among women) widens the household-level gap.

Education and skills (2 marks)

University graduates earn around 70 percent more over their working lives than those with Year 12 only (Grattan Institute), so differences in educational attainment translate directly into differences in lifetime income and, through savings, wealth.

Capital and asset returns (2 marks)

Capital gains from housing and shares accrue disproportionately to households that already own assets, so existing wealth compounds faster than wages can close the gap - the single biggest driver of the WEALTH gap specifically, as distinct from the income gap.

Marking spine: 2 marks per source (1 for correct identification, 1 for a mechanism linking it to the quintile gap); three DIFFERENT sources required for full marks; a fourth or more analysed with a mechanism can substitute for a weaker one.

A 20-mark extended response (Section III/IV style) needs a sustained, judged argument across impacts AND policy, not two separate lists.

Band 6 PLAN.

Thesis: Australia's income inequality is moderate and has been stabilised by a strongly redistributive tax-transfer system, but wealth inequality is more severe and has continued to widen because current policy targets income flows far more effectively than asset stocks, leaving real economic and social costs only partly addressed.

Argument 1 - economic impacts operate through aggregate demand and long-run growth. Evidence: Australia's after-tax Gini is about 0.32 (ABS, 2024 indicative) against a market-income Gini of about 0.45. Mechanism: lower-income households have a higher marginal propensity to consume, so a more unequal distribution of a given national income can reduce aggregate consumption and slow demand-side growth (a circular-flow argument); OECD research links high inequality to lower social mobility and weaker long-run human-capital-driven growth.

Argument 2 - social impacts are concrete and unevenly distributed. Evidence: about 13 percent of Australians live in relative poverty (ACOSS/UNSW), a roughly 6-year life-expectancy gap exists between the highest and lowest socioeconomic quintiles (AIHW), and about 30 percent of low-income renters face rental stress. Mechanism: these social costs compound with wealth inequality, since renters (typically younger, lower-wealth) miss the capital gains that owners (typically older, wealthier) capture, widening intergenerational inequality.

Argument 3 - policy is effective on income, weaker on wealth (the evaluative core). Evidence: progressive income tax (0 to 47 percent including the Medicare levy) and means-tested transfers cut the Gini by about 0.13; compulsory superannuation rose to 12 percent of wages from 1 July 2025. Mechanism/evaluation: these tools are well-targeted at the income FLOW, but the capital gains tax discount and negative gearing concessions on investment property disproportionately benefit existing asset owners, and superannuation compounds fastest for continuously high earners - so the same policy mix that narrows income inequality does comparatively little to narrow wealth inequality, which is why wealth concentration (the top quintile's approximately 60 percent share) has persisted.

Counter-weight / judgement: moderate inequality is not costless to remove and is not purely negative - returns to education and entrepreneurship provide efficiency incentives - so the policy goal is not zero inequality; conclude that Australia's redistribution is comparatively effective on income but wealth inequality remains the harder, still-unresolved problem.

Model paragraph (Argument 3). The sharpest test of Australia's redistributive policy is not whether it reduces inequality overall, but which TYPE of inequality it reaches. On income, the evidence is strong: a progressive tax scale running to 47 percent (including the Medicare levy) combined with means-tested transfers such as the Age Pension, JobSeeker and Family Tax Benefit pulls the Gini coefficient down from about 0.45 (market income) to about 0.32 (disposable income), a reduction of roughly 0.13 that places Australia among the more redistributive OECD economies. On wealth, the same policy architecture is far less effective: the capital gains tax discount and negative gearing concessions on investment property are concentrated among households that already own assets, and even compulsory superannuation, lifted to 12 percent of wages from 1 July 2025, compounds fastest for those with the highest and most continuous incomes. The consequence is a redistribution system asymmetric by design - strong on the income flow, weak on the wealth stock - which explains why the top quintile's approximately 60 percent share of wealth has proven far more persistent than the corresponding, more moderate, 40 percent share of income.

Marker's note: markers reward genuine ANALYSIS (a mechanism linking cause to impact, not description) across BOTH economic and social impacts; an EVALUATION of policy that distinguishes its effectiveness on income versus wealth rather than simply listing programs; CURRENT, DATED Australian data throughout (Gini values with "2024 indicative" or ABS/AIHW years, the 12 percent superannuation guarantee "from 1 July 2025"); and a calibrated, explicit judgement. A response that treats "reducing the Gini" as automatically wholly good (ignoring incentive effects), or that never distinguishes income policy from wealth policy, cannot reach the top band.