Measuring inequality of opportunity through between-group inequality components

摘要

Opportunity egalitarians support rich-to-poor redistribution whenever this allows for the compensation of income disparities due to non-responsible choices (circumstances). In this paper we focus on the measurement of opportunity inequality within Roemer’s (Philos Public Aff 22:146–166, 1993) pragmatic theory where a disjoint and exhaustive partition rule is assumed such that individuals within the same population can be grouped depending on the sole circumstances. Given entropy-based, deprivation-based and welfaristic inequality decomposition procedures, we show that the between-group Gini component from Dagum’s decomposition is the only well known between-group inequality index satisfying the Pigou-Dalton principle of transfer as reformulated for opportunity egalitarianism.