3 ms·

Do you have a link for 3? It would probably affect my answer[0] as I was assuming that the probability of dying between ages x and x+1 increases as a power law

Do you have a link for 3? It would probably affect my answer[0] as I was assuming that the probability of dying between ages x and x+1 increases as a power law after age 60 (which fits well for 60 <= x <= 100, but I don't have data for beyond 100). [0] http://math.stackexchange.com/a/387581/4873 http://math.stackexchange.com/a/387581/4873

gjm11 13y ago
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.
- crntaylor 13y ago
  The latest iteration of the code (I fixed the bug you pointed out, and another one that I spotted myself) reports 1 death per 0.66 years, which is close to 2 per year. The remaining difference, as you said, could be due to the mortality rate in my model not accelerating fast enough past 100 years old. I'll have a play and let you know.

gjm11 13y ago

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.

crntaylor 13y ago
The latest iteration of the code (I fixed the bug you pointed out, and another one that I spotted myself) reports 1 death per 0.66 years, which is close to 2 per year. The remaining difference, as you said, could be due to the mortality rate in my model not accelerating fast enough past 100 years old. I'll have a play and let you know.