ok…i recently got into an agruement about life expectancys and i was hoping that people here can spred some light on it.
to try to keep it simple: life expectancy (numbers are just random) in 1974 is 73. And this year 2001 it is 76. This is only the basic life expectancy, nothing to do with lifestyles.
-my view is that i was born in 1974 and my life expectancy is still 73 to this day.
-one friend’s view is that my life expectancy moves up with the current rate, so my expectancy is now 76
-another friend says it is actually a relation of how old people are dying that year…so it just says your likely to die this year if you are 76 or older
i was hoping some body can help me out and explain the whole life expectany thing to me…thanks!
Don’t have much of an answer, macheez, sorry, but thought I’d say hi anyway. I’m Ross. Think of me as a kind of Doperland Cheshire Cat…
Coupla thoughts:
You can expect to be any age you fancy. God seems to find many of my expectations highly amusing, so I don’t see why this should be any different.
I thought about the maths of it and got thusfar before my brain started to hurt: assuming that there isn’t some official way of calculating life expectancy written down somewhere which means it always just goes by the year of birth, I’d suggest that the gently rising life-expectancy figure is a sign of improving public health etc, and that it could be applied to anyone born anytime. I mean, my life expectancy drops if I start smoking, right? Surely the other factors that influence life expectancy are just as applicable to me. Whatever they are.
I hafta stop posting right after a nightshift…
*[slowly fades and vanishes, leaving perplexed look hanging in the air]
None of your assumptions are exactly correct. Life expectancy in 1974 was based on the average age of death of US citizens (assuming US figures) in 1974. These averages are calculated over a period of time, whether twelve months or ten years I don’t know. If we assume ten years then saying the average life expectancy in 1974 was 73 simply means that between 1975 and 1974 the average age of death was 73 years. Saying the current life expectancy is 76 simnply means that in the past 10 years the avergae person died at age 76. Simple huh.
Your view : Date of birth has no influence whatsoever on the national figures and hence anyones actual life expectancy including yours*. If you were born in 1974 you are now past the most dangerous stages of your life (temporarily) and your actual life expectancy will be higher than it was 10 years ago and higher than the national average. Your personal life expectancy can only be correlated with national figures if you start at the time of your birth. Considering the 1974 figures would have incorporated deaths from the Vietnam war your life expectancy is almost certainly higher than the 1974 figures.
Your 1st friends view:Your life expectancy can be expected to rise and fall with the national average to some dgree, reflecting advances in medical science and geriatric care. However this is not 100% correlated since, for example, a major war will cause a dramatic drop in life expectancy for the population in general and for males in your age bracket particularly. If you don’t go to war there is no reason to suspect that your personal life expectancy will decrease however.
Your 2nd friends view: Again not quite accurate. Average life expectancy is an average figure. For every person dieing at age 10 then a lot of people will be dieing at 85 if the average figure is 76. At age 76 you do not have a 50% chance of dieng that year. The figure simpy means that if you reach 77 you have beaten the odds and have lived longer than 50% of the population over the past 10 years.
So to sum up and hopefully clarify: Your actual life expectancy is in no way reflected by average life expectancies unless you start counting at time zero. You can’t use average, national life expectancy figues to calculate life expectancy except when looking at a new born child. Figures vary too much throughout you life span. Your chances of dieing between 25 and forty are very different to your chances of dieing at ages 60-70. Life insurance companies do have figures on your chances of dieing within any given time period based on your age. These are age based life expectancies and can vary dramtically from national figures. Average life expectancies are only of practical value for things like calculating the future need for nursing homes etc. or giving an indicator of a countries economic status. They make the fundamental assumption that social and medical conditions will not change over the average lifespan of a human being, and since this is not true the figures can’t be used for predicting the life expectancy of a 27yo.
*Obviously date of birth has a bearing on life expectancy in the sense that it determines age, but if a 27yo form 1974 were transported via time machine to 2001 he would have the same life expectancy of you assuming all else is equal.