Correction

April 1997 View as JSON

A correction is provided for the Gini coefficient formula used in February's lead story, detailing the proper mathematical calculation with cumulative proportions of households and income.

There was an error in the formula for February's lead story about the Gini coefficient.

The correct formula is:

Gini coefficient=1 - SUM ( (Xi-Xj) * (Yi+Yj))

where: X is the cumulative proportion of households; Y is the cumulative proportion of income; i is a particular income category; j is i-1, or the preceding income category. *Xi, Xj, Yi, Yj must equal one or less