How does the Gini coefficient summarize inequality?
The Gini coefficient summarizes how far an income or consumption distribution departs from perfect equality.
Mechanism and examples
Zero represents perfect equality and one hundred complete inequality on that scale. It derives from the area between the Lorenz curve and equality line. Household size, income definitions and post-tax measurement affect results. Analysis should state the assumption that other conditions remain unchanged, because simultaneous changes in real data can alter the outcome. In practice, it first identifies the decision makers, the price or quantity that changes, and the time horizon over which the response is measured. This explains why the same concept can produce different outcomes for households, firms and whole economies.
What matters when interpreting it?
The same value can arise from very different distributions and does not show poverty levels. Cross-country comparison requires compatible surveys and welfare concepts. Small changes may reflect sampling error. Data sources, periods, price adjustments and comparison groups can affect the result. To understand why an indicator changed, it is checked against related production, income, employment or price evidence. The concept should therefore be used as an analytical comparison tool with visible assumptions, not as a certain forecast or personal financial recommendation on its own.