HKLNA Project - Calculating the GINI coefficient

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Calculating the GINI coefficient

Supplement 1
graph 35e | table 35

G = 1.0 - $Σ$ ⁿ [p_i(q_i+q_i-1)]
where p_i =	the proportion of all observations that fall into the ith interval
where q_i =	the proportion of all income received by those who fall into the ith interval plus the proportion of all income received by those of each of the lower intervals.
where n =	the total number of intervals
Note: The number of intervals depends on their size. For national income data the quintile (20%) is commonly employed. The decile (10%) is employed in graph 35e. When a quintile is utilized n = 5. A decile yields an n = 10. The summation operation occurs across all intervals i = 1 to n.