Household welfare: income and what it buys
Welfare means how well off a person or group is. For one family (a household), the first guide is income: wages, profits, rent, interest and government support. More income usually means more things the family can buy, so welfare is higher.
But income is not the same as welfare. A family also needs to look at its prices (what its money can buy), its savings and its spare time. A family with a high income but huge rent may have less left to enjoy than a family with lower income and low costs.
Real income = money income adjusted for prices. If prices double and income stays the same, welfare falls.
Social welfare: everybody together
Social welfare is the welfare of the whole society. A simple way to find it is to add up the welfare of every household. But two societies with the same total can be very different: in one, everybody has a fair share; in the other, a few have most of it.
So economists also look at distribution (who gets how much). Tools such as the Lorenz curve and the Gini coefficient show how equal incomes are. A society may prefer a slightly smaller total if it is shared more fairly. This is a value choice, not only a calculation.
Pareto optimum and maximum welfare
A change is a Pareto improvement if at least one person gains and nobody loses. A situation is a Pareto optimum (Pareto efficient) when no more Pareto improvements are possible: to help one person you must hurt another.
Important: a Pareto optimum is not always fair. If one person owns everything, that can still be a Pareto optimum, because giving anything to others would make that person worse off.
Maximum welfare is the best situation judged by society, using a view on fairness. It is chosen from the Pareto-optimal states. So: Pareto optimum is about efficiency, maximum welfare is about efficiency plus fairness. Many policies (like taxes that help the poor) are not Pareto improvements because somebody pays, yet society may still choose them.
Well-being beyond money
Well-being is a wider idea than income. It includes health and long life, education, free time, safety, clean air and water, friends and family, and a say in how the country is run. Surveys of life satisfaction and indexes such as the Human Development Index try to measure it.
Why not just use GDP? GDP counts what is made and sold. It ignores unpaid work (such as caring for children), free time and the health of nature. Rich countries often find that after a point, more income adds only a little to happiness, while health and relationships add a lot.
Green GDP
GDP is the value of all goods and services made in a country in a year. It does not subtract the harm that production does to nature, such as polluted air or lost forests.
Green GDP = GDP โ the money value of environmental damage (and the loss of natural resources). If a factory adds 10 to GDP but its pollution causes damage worth 4, the green gain is only 6.
Green GDP is hard to measure, because we must put a price on things like clean air. Still, it reminds us that growth which eats up nature is not free.
Try it: your family welfare list
Write ten things that make your family's life good. Mark each one: can money buy it directly (yes) or not (no)? Count the "no" marks. Then in the 3D, step 3, see which balls money cannot buy.
Key formulas and definitions
- Real income = money income รท price index ร 100
- Social welfare (simple) = sum of household welfare
- Pareto improvement: someone gains, nobody loses
- Green GDP = GDP โ environmental damage
Worked examples
1. Four households earn 30, 50, 20 and 40 per week. What is the simple total? Who is above the average?
Total = 30 + 50 + 20 + 40 = 140. Average = 140 รท 4 = 35. The households with 50 and 40 are above the average.
2. A government moves 5 from the household with 50 to the household with 20. Is this a Pareto improvement? Did the total change?
No. The 50 household loses 5, so someone is worse off. The total is still 140, only the distribution changed (45 and 25).
3. A new factory raises GDP by 120 and causes pollution damage worth 45. Find the green gain.
Green gain = 120 โ 45 = 75.
4. A country has GDP 800 and environmental damage 150. Find the green GDP and the damage as a share of GDP.
Green GDP = 800 โ 150 = 650. Share = 150 รท 800 = 0.1875, about 19%.
5. Income rises 10% but prices rise 10% too. Did real income change?
No. Real income stays the same, because the money buys the same amount as before.
6. Town A: income 40, clean air. Town B: income 44, polluted air, long commute. Which town can have higher well-being and why?
Town A can. The 10% higher income in B does not make up for bad air and lost time. Well-being includes health, free time and environment, not only income.
Common mistakes
- Thinking higher GDP always means higher welfare. GDP ignores distribution, free time and nature.
- Believing a Pareto optimum is always fair. It only says nobody can gain without another losing.
- Calling any tax a Pareto improvement. A tax makes the payer worse off, so it is not one.
- Subtracting damage from the wrong number: green GDP is GDP minus damage, not damage minus GDP.