Following on from a recent presentation on cost-effectiveness in longevity research, here's an interview with Aubrey de Grey of the SENS Foundation at 80,000 hours: "ZR: Back to matters financial... How much funding would your programme actually need to complete its goals? Paraphrasing your talk again, you guesstimated '$50,000,000 allocated appropriately would be 'enough for the next while''. Can you be a bit specific about what 'the next while' means? ... AdG: I think I said $50M per year. 20M/year would be a good start, and I think above $100M/year we'd be reaching diminishing returns. This is tiny compared to (for instance) the NIH budget, but that's because it's only the budget for the next several years, when the key work will be on mice rather than humans. ... It's pretty clear that a dollar makes more difference when spent on early-stage biomedical research (which is what we'd spend it on) than on the delivery of existing therapies. ... ZR: How confident are you about the success of your program? I'll paraphrase a couple of off-the-cuff remarks on the subject you made in your 80K talk: 'We'll get to robust human rejuvenation - within the next 25 years with 50% probability.' 'I'd give a 10% chance we won't get there for 100 years.' Would you modify these now you're not on the spot? What exactly do you mean by robust human rejuvenation? Is that the same thing as reaching what you call the ageing escape velocity? (for the benefit of readers: the point at which progress in our ability to extend our lifespans surpasses the rate at which we age, effectively making us immune to age-related death) ... AdG: I still stand by both those statements, but please note that I always add the caveat that the former depends on adequate funding, especially in the coming decade. I define 'robust human rejuvenation' (RHR) as the addition of 30 years of extra healthy life to those who are already 60 when the therapies are first given. Longevity escape velocity is different - it's the postponement of aging faster than time is passing, which results from continued progress in improving the comprehensiveness of the therapies. The moment at which we reach LEV, which we call the Methuselarity (and we're pretty sure there will be inly one such moment, i.e. that once we exceed LEV we will never fall below it again), will probably occur at around the same time when we achieve RHR - maybe a little sooner, maybe a little later."