Gini Coefficient Formula

The Gini coefficient measures income inequality using the formula:

\[ I_G = \frac{\sum_{i=1}^{N-1} (p_i - q_i)}{\sum_{i=1}^{N-1} p_i} = 1 - \frac{\sum_{i=1}^{N-1} q_i}{\sum_{i=1}^{N-1} p_i} \]

Where:

• \( p_i \) is the cumulative population share
• \( q_i \) is the cumulative income share
• \( N \) is the total number of individuals or groups