Dean Spears and Mark Budolfson have just published a paper with what appears to be a very important result. It's not yet on Sci-Hub and the academic login details a friend had shared with me expired, so I can't access it, though this seems to be a precursor to it. [Update: a user kindly sent me a copy of the paper, which you can download from here.] I haven't stayed abreast of recent developments in population ethics, so I'd be curious to hear what folks more knowledgeable in this area than I am have to say about it.
The population ethics literature has long focused on attempts to avoid the repugnant conclusion. We show that a large set of social orderings that are conventionally understood to escape the repugnant conclusion do not in fact avoid it in all instances. As we demonstrate, prior results depend on formal definitions of the repugnant conclusion that exclude some repugnant cases, for reasons inessential to any “repugnance” (or other meaningful normative properties) of the repugnant conclusion. In particular, the literature traditionally formalizes the repugnant conclusion to exclude cases that include an unaffected sub-population. We relax this normatively irrelevant exclusion, and others. Using several more inclusive formalizations of the repugnant conclusion, we then prove that any plausible social ordering implies some instance of the repugnant conclusion. This understanding—that it is impossible to avoid all instances of the repugnant conclusion—is broader than the traditional understanding in the literature that the repugnant conclusion can only be escaped at unappealing theoretical costs. Therefore, the repugnant conclusion provides no methodological guidance for theory or policy-making, because it does not discriminate among candidate social orderings. So escaping the repugnant conclusion should not be a core goal of the population ethics literature.