Abstract
It seems to be a widespread opinion that increasing the length of existing happy lives is better than creating new happy lives although the total welfare is the same in both cases, and that it may be better even when the total welfare is lower in the outcome with extended lives. I shall discuss two interesting suggestion that seems to support this idea, or so it has been argued. Firstly, the idea there is a positive level of wellbeing above which a life has to reach to have positive contributive value to a population, so-called Critical Level Utilitarianism. Secondly, the view that it makes an outcome worse if people are worse off than they otherwise could have been, a view I call Comparativism. I shall show that although these theories do capture some of our intuitions about the value of longevity, they have such counterintuitive implications in other cases that we ultimately have to reject them.