Income Versus Wealth
Definition
Income: a flow of money received over a period of time, such as wages, interest, rent, profit and transfer payments.
Wealth: a stock of assets owned at a single point in time, such as property, shares, savings and pension funds.
- Income is measured over a period, for example £2,000 each month or £24,000 each year, so a time unit must always be attached.
- Wealth is measured at a single moment, like a photograph of everything a household owns on one day.
- Because a flow needs a time dimension, £2,000 only has meaning once we say it is earned each month.
- Because a stock is a snapshot, £150,000 of assets is stated for one instant, with no time period attached.
- The two are different quantities, so an answer must never treat an income flow as if it were a wealth stock.
Key Idea
- Income is a flow measured over time, whereas wealth is a stock measured at a point in time.
- Wealth is usually distributed far more unequally than income.
Flow And Stock
- Think of wealth as the water already in a bath and income as the water flowing in from the tap.
- Each period the income flow adds to the existing stock of wealth.
- Spending drains the stock, like water leaving through the plughole.
- When saved income exceeds spending, the stock of wealth rises over time.
Example
- A worker earns £2,000 each month and saves £400 of that income.
- Saving 20% of income adds £400 × 12 = £4,800 to her stock of wealth over the year.
- The £150,000 house and savings she already owns are her wealth stock today, while the £2,000 monthly figure is her income flow.
How They Reinforce
- Wealth generates income, because assets pay rent, interest, dividends and profit.
- That extra income can be saved, which adds further to the stock of wealth.
- This feedback loop means those who already own assets can pull further ahead.
- As a result, small differences in starting wealth can widen into large gaps over time.
Example
- A landlord who owns three flats worth £600,000 receives £2,400 each month in rent, which is income earned from wealth she already holds.
- She reinvests the rent to buy a fourth flat, so both her wealth and her future rental income rise.
Why It Matters
- Living standards depend on both the income a household receives and the wealth it can draw on.
- A person can hold high wealth but low income, such as a retired homeowner with a £150,000 house but only a £600 monthly pension.
- A person can earn high income but hold low wealth, such as a graduate earning £3,000 each month with £40,000 of student debt.
- Taxing wealth to improve equity can weaken the incentive to save and invest, so the equity gain may carry an efficiency cost — though it depends on whether the wealth is productive capital or idle assets.
Exam technique
- State clearly that income is a flow and wealth is a stock, naming the time dimension of each.
- Give one source of income and one form of wealth to show you understand both.
Common Mistake
- Do not use the words income and wealth interchangeably in an answer.
- Do not call saving income, because saving is the act of turning an income flow into a wealth stock.
Self review
- Define income and state why it is a flow.
- Define wealth and state why it is a stock.
- Give one way in which wealth generates income.
- Which is usually distributed more unequally, income or wealth?
