Multiple selves is a conventional assumption in behavioural welfare economics for modelling intrapersonal well-being. Yet an important question is which self has normative authority over the other. In this paper, we tackle this ethical question from the ontological question of personal persistence: what does it take for an individual to persist from one time to another? We review the main theories of personal persistence offered in analytic philosophy and discuss the philosophical problems related to the alternative unified assumptions of the self offered in the critical literature of behavioural welfare economics. We discuss two main issues. First, most of the authors defending a unified account of the self in normative economics tend to c...