That figure is average life expectancy. IE 50% of US man are expected to reach 77.
I can’t access the full paper that this is in reference too, so I’m not sure how they calculate it… but isn’t life expectancy usually the mean age of death? I would expect the distribution to have a left skew from people who die young, which should mean that more than 50% of US men are expected to reach 77.
To me mean = average, so the two statements are the same.
Are you talking about median age of death?
When child mortality was very high (pre- 20 century) that was definitely the case. I am not so sure that it is now. I feel that average life expectancy will be a lot closer to 50% survival rate (median age of death) than it was in the past.
To me mean = average, so the two statements are the same.
Are you talking about median age of death?
The median is the midpoint of a sample, not the mean. So, the median point represents the age where 50% of people will live to, the mean does not represent that (it’s often relatively close to the median assuming the data doesn’t have too much skew, but it can be way off).
When child mortality was very high (pre- 20 century) that was definitely the case. I am not so sure that it is now. I feel that average life expectancy will be a lot closer to 50% survival rate (median age of death) than it was in the past.
There are still plenty of people who die young, even though child mortality is less of a factor in wealthy countries right now. Plenty of people die in car accidents at a relatively young age, for instance. I’m sure the median and mean aren’t like 10 years off of each other, but I wouldn’t be surprised if they’re 3 or even 5 years off, which could be pretty significant in this context.
Well, the definition of the mean and median of a sample doesn’t depend on the particular data set, and there’s plenty of non-age related causes of death in the world which would logically skew the distribution to the left! You can look at actuarial tables to see this in action:
Male life expectancy at birth in this table is 74.12, but you’ll notice that you don’t get to 50% of the population dying until somewhere between the ages of 78 and 79.
This website has a pretty good chart showing the skew for a 2019 dataset:
I can’t access the full paper that this is in reference too, so I’m not sure how they calculate it… but isn’t life expectancy usually the mean age of death? I would expect the distribution to have a left skew from people who die young, which should mean that more than 50% of US men are expected to reach 77.
To me mean = average, so the two statements are the same.
Are you talking about median age of death?
When child mortality was very high (pre- 20 century) that was definitely the case. I am not so sure that it is now. I feel that average life expectancy will be a lot closer to 50% survival rate (median age of death) than it was in the past.
The median is the midpoint of a sample, not the mean. So, the median point represents the age where 50% of people will live to, the mean does not represent that (it’s often relatively close to the median assuming the data doesn’t have too much skew, but it can be way off).
There are still plenty of people who die young, even though child mortality is less of a factor in wealthy countries right now. Plenty of people die in car accidents at a relatively young age, for instance. I’m sure the median and mean aren’t like 10 years off of each other, but I wouldn’t be surprised if they’re 3 or even 5 years off, which could be pretty significant in this context.
Well, both of us are making assumptions without doing the research.
So. I respect your opinion but neither of us knows that we are actually correct.
Well, the definition of the mean and median of a sample doesn’t depend on the particular data set, and there’s plenty of non-age related causes of death in the world which would logically skew the distribution to the left! You can look at actuarial tables to see this in action:
https://www.ssa.gov/oact/STATS/table4c6.html
Male life expectancy at birth in this table is 74.12, but you’ll notice that you don’t get to 50% of the population dying until somewhere between the ages of 78 and 79.
This website has a pretty good chart showing the skew for a 2019 dataset: