epigon
n. one of a later generation

If we decide today that the world would be better off with a smaller population, and take steps to bring this about, then we’re denying life to future people who would otherwise have existed. Is this wrong?

“This difficulty is obvious when we ask, ‘For whom would it be better to have a larger or a smaller population?'” write philosophers Axel Gosseries and Lukas H. Meyer. “For someone whose very existence is contingent on the demographic decision at stake, how can we possibly say that a larger population or a smaller one would, ceteris paribus, be better?”

(Axel Gosseries and Lukas H. Meyer, eds., Intergenerational Justice, 2009.)