A person who is among the poorest 10 percent of the people in the U.S. today may rightly feel unfortunate, even if she is quite well off in absolute terms and better off than 95 percent of the world’s current population and 99.9 percent of the world’s population over the past five millennia. [T]he judgment that she is unfortunate is based on a comparison with other contemporary Americans.
It is important to notice, however, that these comparative judgments presuppose different comparison classes. When we judge that I am not unfortunate for being unable to walk on walls (even though flies can and I would certainly be better off if I could), the relevant comparison class is the entire human species. If a significant enough fraction of the human population were to acquire the ability to walk on walls, then I might feel unfortunate, just as I would now if I were unable to walk at all. In the case of the poor American, the comparison class is narrower. In other cases, it is even narrower still. During his recent tribulations, Michael Jackson elicited a copious flow of pity for his unfortunate condition, the assumption being that anything less than perfect bliss must count as a deprived state for a star entertainer.
Jeff McMahan, ‘Cognitive Disability, Misfortune, and Justice’, Philosophy and Public Affairs, vol. 25, no. 1 (Winter, 1996), pp. 3-35