Measuring Longevity, Another Way

            How deeply have you sipped from life’s glass? How much is left?

That’s a serious question. Answering it, in quantitative way, may tell us something about how we should think about, and plan, our futures. The answer could also give us a framework for thinking about longevity and the issues it presents.

Only a century ago an early death— in childbirth, childhood and long before old age— was the common fate of most Americans. Today, the problem is longevity. We don’t save enough to pay for our increasing years of life. We don’t want take care of ourselves or pay the bills for healthcare later, either.  And, as if that isn’t troubling enough, we’re just beginning to discover that longevity, like wealth or income, isn’t evenly distributed. Some people live a lot longer than others.

This is well beyond bedtime talk for actuaries. We can find it in recent films. “The Hunger Games” is all about a rich capital having the power of life or death over the districts it dominates. “Elysium” is all about the ultimate gated community, a satellite for the very rich with cures for disease that it doesn’t share with the virtually enslaved poor population on a polluted earth.

We all root for Katniss and Max.

So I’d like to make a suggestion. Let’s see just how much the cup of life holds. If we do that we have a rough measure of how much we’ve drunk from it if we live to different ages.

How can we do this? We can spend some time examining the Life Table for the United States. We can see what percentage of the person-years available to Americans we have lived as we age from birth to age one hundred. (A person-year is one year of life by one person.) This isn’t predictive information for individuals, it simply tells us what the current expectations of life are for a broad group of Americans. It’s reality.

We can get this information from the Centers for Disease Control website. Its tables, constructed by actuaries, estimate what happens to a broad population of Americans from birth to death. Starting with 100,000 births, the tables estimate the total number of person-years of life for the group, the number of deaths each year and the number of person-years remaining at the end of each year. The same data can be presented as a graph.

Since the table stops at age “100 and over” the maximum possible number would be 10 million person-years (100 years x100,000 lives).  Even the starting number tells us something:  Instead of 10 million, it’s 7,851,473 person-years. That means we’ve now captured 78.5 percent of possible person-years. We can do better, of course, but that figure is a gigantic improvement from the 5,358,122 person-years of 1910 or even the 6,573,625 person-years of 1940. Viewed another way, we’ve gained a stunning 2,493,335 person-years in the last century.

That’s the good news. It’s also the current size of life’s cup. Beginning from a cornucopia of 7,851,473 person-years of life, the remaining person-years decline year by year. By age 100, only a few drops remain— 4,785 person-years. The decline is a big reminder of Jim Morrison’s message, “No one here gets out alive.” Here is what it tells us at different ages:

  • By age 40 we’ve used 51 percent of our person years, only 49 percent remain. Small wonder so many 40 year olds get “over-the-hill” cards on their birthday.
  • By age 65, the beginning of what demographers now call the “young-old” group, we’ve used 78.5 percent of our person-years, with only 21.5 percent remaining.
  • By age 75, the start the “old” group, we have only 11.5 percent of our person-years remaining.
  • By age 85, as we enter the “old-old” group, we have used 96 percent of our person-years, only 4 percent remain.
  • By age 90 only 1.7 percent of our person-years remain.
  • By age 95 only 0.1 percent of our person-years remain.

What do these figures tell us? Interpretations will vary, but the message I get is that people who prefer to eat dessert first are quite reasonable. The glass empties pretty fast. Another message is that a 20-year planning horizon— as in age 65 to 85—is likely to be a lot more rewarding than a 30-year planning horizon, even if it entails a greater risk of dying broke.


Related columns

Scott Burns, “Should We Eat Dessert First?” 4/29/11 http://assetbuilder.com/scott_burns/should_we_eat_dessert_first

Scott Burns, “Life— How Much Will You Leave On The Table?”  4/8/2012 http://assetbuilder.com/scott_burns/life_how_much_will_you_leave_on_the_table

Scott Burns, “How Much Is a Future Year Worth?” 7/20/2012

http://assetbuilder.com/scott_burns/how_much_is_a_future_year_worth

Scott Burns, “Life, Death and How Long Your Money Will Last, 11/9/2012 http://assetbuilder.com/scott_burns/life_death_and_how_long_your_money_will_last

Scott Burns, “The Coming Longevity Gap Battle,” 3/30, 2014 http://assetbuilder.com/scott_burns/the_coming_longevity_gap_battle

On the web:

Center for Disease Control, Life Tables for the United States

http://www.cdc.gov/nchs/products/life_tables.htm


This information is distributed for education purposes, and it is not to be construed as an offer, solicitation, recommendation, or endorsement of any particular security, product, or service.

Photo: Scott Burns: The harbor in La Rochelle, France

(c) A. M. Universal, 2014