Some more statistical observations, looking at longevity data from the worlds oldest (dead) people.
I went and grabbed the list of verified oldest people from wikipedia and threw out all the ones who are still alive, leaving 92 humans who died after age 114 years, 93 days.
When you look at the data by ‘number of days lived since 114+93’ (I would have made it a round 114, if I’d had the data…) it’s messy. Even 92 data points is a moderately small set. You can call Calment an inexplicably far outlier, but you could also point to the area at around +250 days as being inexplicably low. Is there some weird factor suppressing deaths at age 114 and 10 months? It doesn’t seem likely. It’s just a random variation.
Next, working on the model that after age X you have a constant whatever-percent chance of dying in each time period, I did three models to figure out what the mosty likely per-day chance of survival was under three conditions: using all the data, removing just Jeanne, removing Jeanne and Sarah Knauss. The result was.
All data: 99.802% per day
Exclude Jeanne: 99.756% per day
Exclude Jeanne and Sarah: 99.756% per day
IOW if you make it to 114+93, on any given day your chance of making it to the next day is very close to 99.8%. Assuming Jeanne is an invalid data points makes a noticeable difference to the calculated value, but assuming Sarah is invalid makes nearly none. At this point, I’d say that the statistical argument for being suspicious of Sarah Knauss’ age at death is basically DOA, but Jeanne needs a little more investigating.
I did a plot of the number of people who have ever lived to an age of “n days after 114+93”, plus the predicted values of how many people should have been alive, given the chances of death calculated above. The red line is using a chance-of-death-per-day of 99.802%, the blue line is using 99.756%. The blue line certainly fits the data somewhat better. However, as you can see, BOTH lines fit the “Jeanne” data point reasonably well - given that we start with 92 people at age 114+93, both models predict that we’re left with about half a person at day 2991 (Jeanne’s death day). So this is consistent with Jeanne just being a not-unreasonable outlier
Furthermore, if we assume someone has already lived as long as Sarah Knauss, I calculate the chance of living another 1160 days (the difference between Sarah and Jeanne’s age at death) to be .99756**1160 = 0.059 (5.9%). That’s really not a particularly low chance, given that we measure thousands of different statistics about the world all the time. It certainly isn’t statistically suspicious enough to base a conspiracy theory off.