reading it now. i pulled up the longevity calculator and filled in my info. if i retire at 67 i have a 10% chance of living to 90. if i retire at 57 i have a 9% chance if living to 90. i wonder why?
It's a quirk of statistics that seems misleading but actually makes sense.
The thing is that to retire at 67, you have no not have died before age 67. The people who live to 90 had to have been both still alive at 57 and at 67, but they will be a larger percentage of those who were around at 67, since fewer are alive at 67 than at 57.
Oversimplifying a bit (and assuming that when you retire does not affect when you die): Suppose you have a pool of 10,000 people aged 57. Using the statistics you quoted, 9% of them, so 900 are expected to live to age 90.
Now wait ten years. In those intervening years, some of the original pool will have died. To be consistent with the numbers you quoted, about 1,000 of the original 10,000 will die after 57 but before 67. So those surviving to 90 will be 900 of the remaining 9,000. So 900/9,000 is 10%.
Like I said this oversimplifies because it assumes that retirement age is neither a cause nor an effect of age at death, but I think this explains the thing you were wondering about.
Additionally, the population of people who retire early has a disproportionate number of very ill people in it, since there are more people retiring early who are either forced to retire or advised to retire because of poor health than people who are perfectly capable of continuing to work.
It's similar to a study I read that touted the benefits of drinking alcohol (paid for by the alcohol industry), but they didn't separate out non-drinkers from never-drinkers, so the population of non-drinkers included all of the recovering alcoholics and people who had to quit because of medical issues. But the paper was widely publicized as evidence that drinking moderately is so much healthier than not drinking.
Whenever looking at health statistics of a differing group from the norm, you have to examine the reasons as to why people would select to be in that group.
Unfortunately for early retirement, the young, healthy folks who simply choose to leave the workforce in their most lucrative years are vastly outnumbered by those, like me, who had no choice.