All I have for #3 is a brief comment on a Wikipedia page. I wouldn't trust it much, and would in fact expect your model to be nearer the truth. In fact, I'd ex

All I have for #3 is a brief comment on a Wikipedia page. I wouldn't trust it much, and would in fact expect your model to be nearer the truth. In fact, I'd expect your model to be nearer the truth than it actually is. It seems that the true oldest-person death rate is on the order of 2 per year; my argument yields one per 2 years, your simulation yields one per 1.6 years; is it possible that there's a bug still lurking in your simulation code? (I know you fixed one already! ... and I see you've already responded to my asking the same question over on math.se. [EDIT to add: and I think I may have found a bug, which would make your code underreport oldest-death events. I've reported it on math.se.]) What happens as you twiddle the parameters of your power law to make mortality increase more sharply with increasing age? What do you need to do (if it's possible at all) to get the oldest-person death rate up to 2 per year? It's conceivable that there's some bias in the reporting of deaths of oldest living people that causes too many to be reported -- but I haven't been able to think of any remotely plausible mechanism that would have that effect.