 The disability advocate might respond that QALYs and similar measures are simply not valid since the rankings are done by people who do not themselves have first-hand experience with what it means to live with a disability. Indeed there is some evidence that third-party assessments of the objective quality of life of people with impairments—either by health professionals or the general public—are systematically lower than self-assessments by people with impairments (Ubel et al. 2003), and that this bias may well be the result of distortion from cultural and other prejudices (Amundson 2010).