This paper offers a unified explanation for the procreation asymmetry and the non-identity thesis – two of the most intractable puzzles in population ethics. According to the procreation asymmetry, there are moral reasons not to create lives that are not worth living but no moral reasons to create lives that are worth living. I explain the procreation asymmetry by arguing that there are moral reasons to prevent the bad, but no moral reasons to promote the good. Various explanations for the (...) procreation asymmetry have failed to explain the non-identity thesis: if one could create a person with a good life or a different person with a better life, one has a moral reason to create the better life. I argue that reflections on the misfortune of unfulfilled potential allow us to circumvent the non-identity problem. (shrink)