 Another approach to the problems in population ethics has been the suggestion that the crux of the problem resides in an all too “impersonal” morality and that the problems of population ethics can be solved by a shift to a so-called “person-affecting” morality (Narveson 1967, 1976, 1978; Roberts 1998, 2002, 2004, 2007, 2011). This move has been especially popular in the context of medical ethics where many of the problems of population ethics are actualised. Examples are embryo or egg selection, pre-implantation genetic testing, assisted reproduction programs, abortion, to mention just a few. The idea behind this approach is the contention—sometimes referred to as “the person-affecting restriction” or simply “the slogan”—that an outcome can only be better (or worse) than another if it is better (or worse) for someone (Narveson 1967: Glover 1977; Temkin 1993a). If a quite strict interpretation of this restriction is combined with the assumption that non-existence and existence are incomparable in value for a person, we may derive a view called comparativism: We should disregard the welfare of uniquely realisable people, that is, people who only exist in one of the compared outcomes (Heyd 1988; Bykvist 1998). A person-affecting morality so understood deviates from impersonal morality in important respects. If there is an overlap between the populations in A and Z, then A is ranked as better than Z since the people existing in both populations are worse off in Z as compared to A and since we should disregard the welfare of uniquely realisable people. However, if there are different people in the involved populations, such as two future populations, then the two populations are ranked as equally good or as incomparable in value, which is not a very satisfactory solution to the Repugnant Conclusion. Moreover, comparativism implies that any very huge loss in welfare for uniquely realisable people is compensated by any very small gain for non-uniquely realisable people. Less strict interpretations of the person-affecting restriction and comparativism can to a certain extent avoid these problems, but at the price of implying the Repugnant Conclusion again (Arrhenius 2009a; Holtug 2004).