This paper offers an approach to assessing quality of life, based on Sen's (1985) theory, which it uses to understand loss in quality of life due to mobility impairment. Specifically, it provides a novel theoretical analysis that is able to account for the possibility that some functionings may increase when a person's capabilities decrease, if substitution effects are large enough. We then develop new data consistent with our theoretical framework that permits comparison of quality of life between those with a disability (mobility impairment) and those without. Empirical results show that mobility impairment has widespread rather than concentrated impacts on capabilities and is associated with high psychological costs. We also find evidence that a small number of functionings are higher for those with a disability, as our theory allows. The paper concludes by discussing possible implications for policy and health assessment methods.
Keywords: Sen; capabilities; disability; extra-welfarism; health; mobility impairment.
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