Non-parametric estimation and evaluation of capability sets

A major difficulty for the application of Amartya Sen's capability approach is that individual capability sets cannot readily be observed. This article proposes a non-parametric framework to construct such sets, on the basis of observed functionings of individuals that are taken to belong to a group sharing the same capability set. Within this framework, the earlier theoretical proposals of Muellbauer to compare different capability sets can be easily implemented. Associated robust empirical estimators are provided and applied to EU-SILC data on household income, material living conditions, housing quality and health; we illustrate our approach with a multilateral comparison of 32 European countries, with a comparison of both a 'fixed ray' and a 'multiple rays' evaluation metric to compare French and German capability sets, and with a multilateral comparison of socioeconomic sub-groups in France.