Two related asymmetries have been discussed in relation to the ethics of creating new lives: First, we seem to have strong moral reason to avoid creating lives that are not worth living, but no moral reason to create lives that are worth living. Second, we seem to have strong moral reason to improve the wellbeing of existing lives, but, again, no moral reason to create lives that are worth living. Both asymmetries have proven very difficult to account for in any (...) coherent moral framework. I propose an impersonal population axiology to underpin the asymmetries, which sidesteps the problematic issue of whether or not people can be harmed or benefited by creation or non-creation. This axiology yields perfect asymmetry from a deliberative perspective, in terms of expected value. The axiology also yields substantial asymmetry for large and realistic populations in terms of their actual value, beyond deliberative relevance. (shrink)