Thursday, August 1, 2013

Predicting Death With Actuary Tables


The old rusty Nail

A JOURNAL FOR OLD PEOPLE
 
Predicting Death with Actuary Tables

Russell Burton

 
Insurance companies and the IRS use actuary tables to predict life expectancy for people of all ages.  I would think that these would be more properly names as death expectancy tables because they predict at what age you are supposed to die.  Now, let’s be clear they predict the age at which you are supposed to die not the year you are going to die.

These predictions of life expectancy or death expectancy by mathematicians have never been explained adequately, so I will try to clear up any confusion on this subject.  First my argument against the name commonly used for these tables is based on two factors: (1) clearly, one expects to live to the ages that they predict and (2) the age predicted in when they want you to die. I say, they want you to die because without some success using these tables they would be useless and these predictors of death would have to go into some honest work.

But these bean counters are clever for they never stand by their predictions about when you are going to die or like they indicate how long you are going to live.  Why - because they keep changing that date every day that you grow older.  Now, I have done it, using the word ‘grow’ with older.  Although it is used frequently in the context that one is getting older, it seems to me getting older is much different that growing older. 

Now, that we have settled that argument actuary tables do change there predictions of ones death as you get older.  For instance, at age 70 one is expected to die at age 87.  But, at age 80 one is expected to die at the age of 90.  But, of course its not that simple because they change depending on whether a person is living with someone or if that person lives alone.  Certainly sex and race has its effects so their reliability is suspect in many ways.  By the time you get all of these factors straightened your life expectancy has changed for you have gotten older.

Of course these tables are calculated using real death-date numbers, but these change as medical and other social factors improve with time.  For instance, when I was born in 1932 life expectancy was about 68, now when a person is born it is nearly 80 for men and 83 for women. Well, it means that half yes half of my 1932 birth-date members have died before they reach their promised life expectancy date or predicted age of death at about 80. But, how wrong can these tables be for half of my birth-date chums are still alive so these prediction dates are wrong by definition by 50%.

Now that I am 80, these tables now read that I will live to be 90.  My uncle just turned 90 and he is expected to live another 5 years or so.  They keep moving the goal posts further and further out!

As I reflect on my future of living I suddenly realize that it took eighty years to get here and now I have only about 7 years left.  Somehow I feel shortchanged regarding my years of life left.  But with my aches and pains that I now have I don’t think I can handle another 80 years.