Life Expectancy

[Bert45]

I just heard on the news that life expectancy in England has risen to its highest level ever. The newsreader said that a man now aged 65 could now expect to live to 84. What does this mean? Does it mean 50% of English men can expect to live to 84 (and beyond)? Or more like 95% of English men can expect to live to 84 and beyond?
And how do they arrive at this figure? Almost everyone who was born in 1916 is dead now, so they can work out the total life expectancy of someone born in 1916. Add all the ages at death of a sample of people born in 1916 together and divide by the number of people in the sample. But how do you do that for a sample of people born in 1951, as they are not all dead yet?

[Peter Pedant]

oh

http://www.who.int/whosis/whostat2006DefinitionsAndMetadata.pdf

says it is an AVERAGE number of years expected

( remember an average did not the half way point - 50% do and 50% dont that is called a median = very common error )

average is balanced - if you have a dataset 1,2,3,4,1000 - th average is add em all up and divide by 5 which is around 202 and you wil notice four points are below the average and one above

The median - the bumber at which 50% is above and 50% below is 3

for the second part of your question - life expedctancy when they arent all dead such as those born in 1950 - try googing Kaplan Meier survival curves and censored data.....

[Peter Pedant]

this appears to have some answers

http://www.lho.org.uk/Download/Public/7656/1/tech_supp_3.pdf

[Bert45]

Thanks PP. I cannot say I understood what was in the links, but I can believe there is some tricky statistics behind it.

[Peter Pedant]

yeah I returned to them
and altho it is clear they tell you how to calculate life expectancies ...

I thought I would leave it to someone else

[mazie]

And I just thought I wanted to give you a big massive hug Peter xx

[Cloverjo]

I'd like to echo, Mazie. I read about your health problem on another thread, I think. Best of luck to you.

[Cloverjo]

^^^ that was to Peter.

[Peter Pedant]

thank you maze and clove

Bone marrow flat again this week - but it recovers around day 21

just about to have a truncated cycle four - half way there ! ( no not to a coffin )

[fiction-factory]

Hi PP- i mentioned the mean/median issue in the first post but i am not sure there will be much difference between the two in this case since there are not going to be any unusual values like one person living to 300 to distort the figures. Now if it's mean, I wonder if it was arithmetic mean or geometric mean...
I always enjoy your posts by the way, especially in Law. I'm not saying I understand them but they may me smile

[Peter Pedant]

HI FF
well one cant really control what one is stricken with
saying I am treated at the christie is a bit like the question on Airplane -
did you eat the fish canape ?

ho hum - I totter on ( just )