Unit-consistency and polarization of income distributions

Most of the polarization measures proposed in the literature, and likewise the inequality and poverty indices, assume some invariance condition, be that scale, translation or intermediate, which imposes value judgements on the measurement. In the inequality and poverty fields, B. Zheng suggests rejecting these invariance conditions as axioms and proposes replacing them with the unit-consistency axiom (Economica 2007, Economic Theory 2007 and Social Choice and Welfare 2007). This property demands that the inequality or poverty rankings, rather than their cardinal values, are not altered when income is measured in different monetary units. Following Zheng’s proposal we explore the consequences of the unit-consistency axiom in the polarization field and propose and characterize a class of intermediate polarization orderings which is unit-consistent.