My dad, who isn’t competitive at all, asked me recently how old he would have to be before he had outlived 50% of his contemporaries. He suspects he may have passed that age sometime in the past few years. So I’ve been exploring the ABS mortality statistics.
If you look at the most recently produced life table, the answer is that a man must make it about four months past his 82nd birthday (The life expectancy at birth on current rates is 79.2 years – the difference is the difference between a mean and a median).
But that doesn’t tell the whole story. The most recently produced life table uses mortality rates from 2006-2008. So it overstates the chances of living that long, for my dad’s contemporaries, who have lived through a time where mortality rates were worse than they are now. So I had to go and see what I could reconstruct about mortality rates, to reflect the actual experience of my dad’s contemporaries. I’ve cheated, and used Australian statistics for the whole period (my dad didn’t move to Australia until his late 30s, but he lived in New Zealand and the US, mostly, until then).
The difference is actually less than I thought it would be. He has to live to almost exactly 78 years old to outlast half his contemporaries. But his life expectancy at birth (based on the actual experience to now) was only 70 years.
One of the striking improvements in mortality was at birth. 4.5% of babies born back in the 30s didn’t make it to their first birthday (including my dad’s older sister). In 2006-2008 table, 0.5% of babies didn’t make it. Another measure of general improvement is that back when Dad was born, his life expectancy based on mortality rates for the population then was only 63 years. Improvements in medicine, nutrition, and public health have added 7 years to the lifespans of babies born back then.
I just love your blog. Stuff like this I would never know – or be able to work out for myself – if it weren’t for people like you and Deborah.
But you’ve inspired me. I’m going to try and work it out for my grandfather who is turning 95.
I’m always amazed when my geekiest posts get a response! Let me know if you’d like my spreadsheets to get you started.
I loved this too, particularly as it’s the anniversary of my father’s death this week. He died just before his 83rd birthday and he had outlived most of his male relatives, though 83 sounds quite young to me these days, as my f-o-l recently died at 89 – now he had definitely outlasted most friends and family, male and female.
Why do I find this so fascinating? I was thinking about my own life expectancy the other day in relation to a Crumpler bag I bought guaranteed for THIRTY YEARS! The obvious question in my head was, at 47, am I going to outlive the bag’s guarantee or not? Or will it become a kind of family heirloom in a time when no-one actually has laptops anymore?
Are you sure? 78 seems to be a high number for the life expectancy of 79.2.
I think (based on a few people I’ve talked to about this post) I haven’t been clear enough. I may go back and edit it and put a few graphs in. But for now:
There are two main sets of mortality rates I’ve looked at. The most important are the ones affecting my dad’s male contemporaries throughout his life. On these rates, life expectancy at birth was 70, and 50% of them lived to 78.
On the rates experienced right now (ie rates affecting current male newborns, and current 80 year olds, so no actual generation) life expectancies at birth are 79 years, and 50% of this theoretical cohort would live to 82.
So life expectancy at birth has gone up 9 years over that time (70 to 79), but the 50% mark has only gone up 4 years (78 to 82). I think the main reason for that difference has been that much of the improvement has been at the younger ages, particularly at birth.
Life expectancy measures the average number of years lived – my other measure is the median number of years lived. So the reason the median is higher than the mean is that even now, mortality rates in the first year of life are much higher than the years after that – it takes until age 56 until mortality rates are that high again.
I haven’t gone back and checked every single number again, but it makes sense.
I haven’t been hear for a long time, but that is an interesting post. I believe the infant mortality figures are even more improved than that figure suggests as a good portion of the unfortunate 0.5% represents babies who one would have been stillborn but are now induced to be born prematurely having had problems identified during pregnancy.
Would be interesting to say know the rate given some pre-full term conditioning. My memory of a graph I saw once in the prem ward at RPA showing that over the last 20 years the mortality rate of under 1kg babies had decreased from 75% to 25%.