Gini Coefficient. The Gini coefficient is a numerical measure of the extent of income inequality. The Gini coefficient is calculated by dividing region A by the sum of regions A and B:
Gini = A/(A+B)
The Gini lies between 0 and 1. 0 represents complete income equality, everyone earns the same income. 1 represents complete income inequality, one person earns all the country’s income.