The table above shows a computation of inequality indices for four groups.

Goiânia follows a state trend, since Goiás reached its highest economic inequality index for the past decade in 2005.

After 2000, the inequality index declined again.

The Gini coefficient and other standard inequality indices reduce to a common form.

Based on these observations the inequality indices have this common form:

Firebaugh has shown that standard inequality indices reduce to a convenient common form.

It is conceptually one of the simplest inequality index used in econometrics.

In many cases the inequality indices mentioned above are computed from such segment data without evaluating the inequalities within the segments.

The Gini index is the most frequently used inequality index.

The class of the subgroup-decomposable inequality indices is very restrictive.