In the literature on Sen's capability approach, studies focussing on the empirical measurement of conversion factors are comparatively rare. We add to this field by adopting a measure of 'conversion efficiency' that captures the efficiency with which individuals convert their re-sources into achieved functioning. We use a nonparametric efficiency procedure borrowed from production theory and construct such a measure for a set of basic functionings, using data from the wave 2006 of the British Household Panel Survey (BHPS). In Great Britain, 49.88% of the individuals can be considered efficient while the mean of the inefficient indi-viduals reaches one fifth less functioning achievement. An individual's conversion efficiency is positively affected by getting older, being self-employed, married, having no health prob-lems and living in the London area. On the other hand, being unemployed, sepa-rated/divorced/widowed and (self-assessed) disabled decrease an individual's conversion effi-ciency.
conversion efficiency welfare measurement robust nonparametric efficiency analysis functioning production