Thursday, March 13, 2014

"Your body wasn’t built to last: a lesson from human mortality rates"

From Gravity and Levity:

"That decline is no joke; the sharp fall in survival rates can be expressed mathematically as an exponential within an exponential. Exponential decay is sharp, but an exponential within an exponential is so sharp that I can say with 99.999999% certainty that no human will ever live to the age of 130. (Ignoring, of course, the upward shift in the lifetime distribution that will result from future medical advances.) Surprisingly enough, the Gompertz law holds across a large number of countries, time periods, and even different species. While the actual average lifespan changes quite a bit from country to country and from animal to animal, the same general rule that 'your probability of dying doubles every X years' holds true."
Also: "A simple derivation of the Gompertz law for human mortality." [pdf]


Stagflationary Mark said...

This is really good news for me.

With real yields so low, I doubt I can afford to live anywhere near infinitely long without my nest egg running dry, lol. Sigh.

Gallows humor.

whydibuy said...

While it is true that the lifespan for people has increased overall, the real individual human lifespan hasn't changed much from ancient times. Its just that with medical science these days, more people can participate in the higher end of the human lifespan. But the high number hasn't really changed. I think its still in the eighties.
This reminds me of what Buffett said when asked about his ancestors. He said he really wasn't interested in them other than to know what kind of lifespans they had, so he could calculate what his own would be.