Average life expectancy for a population is normally given from birth; but it seems to me more useful to distinguish youth mortality (e.g. from birth-defects or malnutrition) from that of adulthood (violence, accidents) and age (heart disease &c).<\/p>\n
I’d like to see life expectancy stated in the form of two numbers: the age at which future l.e. stops increasing (which measures childhood mortality; if c.m. is very low I guess the critical age is negative), and the l.e. at that age (which measures what we usually think of as longevity).<\/p>\n
This train of thought was prompted by the mention on some blog or other (sorry I’ve now forgotten whose; the background was a pale buff, I think, if that helps) about two brothers who are in business together at ages 100 and 91. The bloguist mused about how it feels to celebrate a centenary birthday and know that one is unlikely to see another. (I commented that a centenarian is more likely to see 101 than he had ever been before!) I’m musing about what it’s like to know somebody for that long. How old can a ‘kid brother’ be, i.e. do people outgrow such hierarchies? (We know that High-Elves don’t, at least not in 2739 years!)<\/p>\n
Later:<\/strong> Steven Gallaher <\/a> shares some pointers and observations. The second derivative starts to look more interesting than the first.<\/p>\n","protected":false},"excerpt":{"rendered":" Average life expectancy for a population is normally given from birth; but it seems to me more useful to distinguish youth mortality (e.g. from birth-defects or malnutrition) from that of adulthood (violence, accidents) and age (heart disease &c). I’d like … Continue reading