When I ran the math, the QALY expected value of the two options actually worked out about the same: http://lesswrong.com/lw/6xk/years_saved_cryonics_vs_villagereach/
This calculation was badly wrong. You allowed for the possibility that cryonically suspended people would wind up living very long and happy lives through future technology (which provided the great majority of the QALYs), but not for the possibility that African children saved from malaria would, many of whom would live another 60-70 years and could benefit from any big wave of technological change, life extension, etc. If you selectively count the biggest QALY benefits for only some interventions but not others you will get seriously misleading results.
Also it omitted all the compounding effects of more people in Africa over coming decades and centuries.
It's a back-of-the-envelop calculation on vast unknowns. I wrote it up because it seemed pointless to try making a decision if we weren't even going to involve numbers. I happily concede that it is deeply speculative.
First, given it's a back-of-the-envelop calculation, I assume that anything LESS than a 100% difference (2:1 value ratio) can effectively be treated as within the margin of error. So if the ratio I got was 1.5 : 1, I'd still say they were approximately equal. I can't off-hand defend this intuition, beyond that it's sloppy math so we have to ...
I am not currently signed up for cryonics. I am considering it, but have not yet decided whether it is the right choice. Here's my reasoning.
I am very sure of the following:
1. Life is better than death. For any given finite lifespan, I'd prefer a longer one, at least within the bounds of numbers I can reasonably contemplate.
2. Signing up for cyronics increases the expected value of my lifespan.
But then I also believe the following:
3. I am not particularly exceptional among the set of human beings, and so should not value my lifespan much more than that of other humans. I obviously fail at this in practice, but I think the world would be a much better place if I and others didn't fail so often.
4. The money it would take to sign up for cryonics, though not large, is enough to buy several centuries of healthy life each year if given to givewell's top malaria charities. Since on average I expect to live another 50-60 years without cryonics, the investment would need to increase the expected value of my lifespan by at least 5,000 years at minimum to be morally acceptable to me.
5. There is a chance we'll discover immortality in my lifetime. If so, then if I signed up for cryonics the payout is 0, and the people who died because I bought insurance instead of charity are people I could have saved for far longer.
So, what do you think is the probability that immortality will be discovered in my lifetime? What about the probability that, if signed up for cryonics, I will live into the far future? These priors would seem to be the key for me to decide whether signing up for cryonics is morally acceptable to me.