Correcting the Concentration Index: A reply to Wagstaff

In this note, I reply to Adam Wagstaff's criticism of my corrected version of the Concentration Index for bounded health variables. I focus on three issues: (1) Wagstaff's suggestions with regard to the scale invariance property; (2) his distinction of relative and absolute inequality; and (3) a comparison of Wagstaff's index W with my index E. I show that his criticism is unfounded, and that his index is not superior to mine.