Economics
Income Inequality and the Gini Coefficient
Quick fact
If everyone in a country earned the same income, the Gini coefficient would be 0. But if one person took all income, it would be 1. In real countries, it's usually between 0.25 (like Denmark) and 0.63 (like South Africa).
Why this is interesting
Imagine slicing a pie and giving one person almost all of it—that's extreme inequality. But how do you measure the exact sliver of fairness?
Read the full explanation
Understanding Income Inequality and the Gini Coefficient
Income inequality is about how unevenly money is spread across people. But a simple statement like "it's unfair" doesn't help compare exactness. The Gini coefficient, named after Italian statistician Corrado Gini, condenses the whole income distribution into a single number between 0 and 1 (or 0 and 100). To visualize it, imagine lining up every person in a country from poorest to richest. Then, plot on a graph the cumulative percentage of income they earn. If everyone had equal income, the poorest 10% would have 10% of income, the poorest 50% would have 50%, and so on—that would create a straight diagonal line. But in reality, the poorest 10% often have far less than 10% of income, and the richest 10% have much more. This reality bends the curve away from the diagonal—this bend is called the Lorenz curve. The Gini coefficient is basically the area between the diagonal line and the Lorenz curve, expressed as a fraction of the total area under the diagonal. The bigger the bend, the higher the Gini coefficient.
A deeper explanation
The Gini coefficient works because it measures deviation from perfect equality. Its formula is a ratio: it divides the area between the line of equality and the Lorenz curve by the total area under the equality line. This gives a scale from 0 (no deviation—everyone equal) to 1 (maximum deviation—total concentration). Why does this matter? Because it gives us a standard, comparable number. When Sweden reports a Gini around 0.28 and Brazil around 0.53, we instantly know the latter has more uneven income. It also tracks changes over time: if a country's Gini rises, inequality is increasing; if it falls, the distribution is becoming more equal. But the Gini coefficient is a summary—it doesn't say why inequality exists or who is rich or poor. It also treats all income sources equally and doesn't capture how inequality feels in daily life. Still, it remains one of the most powerful tools for policymakers, economists, and journalists because it translates a complex social pattern into a digestible figure.