“…Gagolewski has recently proposed the concept of spread measures 25 , which incorporates traditional measures of variation as special cases. Parallels have also been drawn between spread and the notion of disagreement (or lack of consensus) in decision making 1,5,6,14,28,31,32 and with evenness indices used in ecology 8,9 . In turn, we can observe that, historically, many traditional evenness measures were derived from inequality indices 43,44 , since the desireable property that evenness is increased with transfers of abundance from rare to more common species is one that is satisfied by the Pigou-Dalton principle proposed by Dalton 19 .…”