(1) Non-persons and new persons.
Suppose you could either (i) save the life of a ten year old child, (ii) save the life of a ten week old infant, or (iii) conceive and bring into existence an entirely new child. Supposing that the individuals in question will face no future health risks until they die of old age, it appears that the options are listed in increasing order of QALYs thereby "gained". But it seems entirely backward to think that this corresponds to the moral desirability of the options -- (i) is clearly better than (ii), which in turn seems better than (iii).
What we really care about is helping individuals rather than just maximizing QALYs for their own sakes. Bringing additional good lives into existence -- as in option (iii) -- is impersonally good, but arguably is not a benefit for the new person (say if we judge non-existence to be incomparable to good existence). At any rate, it doesn't seem to have the same moral urgency as preventing harms, by which I mean improving the lives of people who will otherwise exist in a worse-off state.
Further, in preferring (i) to (ii), we reveal doubts as to whether future QALYs really benefit an (even already-existing) infant as much as they benefit an older child. (Put another way: it seems that the older child is more harmed by early death than the infant is.) This is arguably due to the relative lack of psychological continuity between the infant and their (possible) future stages. For example, future good experiences in my body only benefit me if I will be the one experiencing them, and the normatively relevant sense of diachronic personal identity here is one that's grounded in psychological continuity: overlapping chains of memories, beliefs, values, intentions, etc. Infants don't have a lot of these, so they are only very weakly connected to their future selves, and so don't lose as much if those future selves are prevented from existing (by early death).
Put this all together, and we get the result that QALY gains to non-persons and to new persons should be significantly discounted.
(2) The Best Years of Our Lives?
Different periods of life are likely to be more or less "central" to the realization of our core life projects and values. For example, perhaps life-years in the period from late adolescence through middle age are generally more important/beneficial for the person living them.
(2a) Positive externalities: Not something I discuss in the paper, but the "central/productive" years of life are also arguably the ones with the greatest positive externalities or "social value" for others. While there's no principled basis for distinguishing direct vs. indirect beneficiaries in general, appeals to social value in health care allocation open up a whole new can of worms, so I won't pursue that further here (but you're welcome to in the comments!)...
(3) "Chunking" effects?
Much of what really matters in life requires significant "chunks" of time to realize. While this can help explain some intuitions about, e.g., favouring a few larger QALY benefits over a larger aggregation of smaller benefits, such intuitions seem to stem from the false assumption that additional QALYs can only help one to complete an important project if the entire project occurs (from start to finish) within the new period of time granted. But of course, even a small life-extension may allow people to complete a significant project that they were already part-way through. So in practice, as is so often the case, I don't think that chunkiness actually ends up making any practical difference.
The value of closure -- saying one's "goodbyes", making final plans, etc. -- might mean that we should give extra weight to even fairly short life-extensions for patients who would otherwise die unexpectedly early (i.e. with no prior warning).
Any further thoughts or suggestions?