In Search Of The Average Doubt:
Why ‘Life Expectancy’ Is Misleading

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The Centers for Disease Control and Prevention in Atlanta recently published findings showing the “life expectancy” of Americans has dropped in part because deaths by suicide and drug abuse have increased. While one might receive such news with keen interest, this writer received it with something approaching disbelief.

At the risk of being labeled a “life expectancy denier,” I shall here venture forth with alacrity and even some recklessness, as I see no reason a mere statistical construct should be deemed one whit meaningful, at least sufficiently meaningful to affect a single life.

Before I continue, clarity is essential:  “life expectancy” is defined by the World Health Organization as the “average number of years a newborn is expected to live if current mortality rates continue to apply.”

Now, if you will, imagine that you, as a truly remarkable teacher, expect your students to score 100 on their quizzes. In fact, you have stats to back this up:  over the last 10 years, when given a particular set of quizzes, every student has had a perfect score.

What if suddenly you begin to include in your data the scores of those students who don’t even take the test? What then will your “score expectancy” be?

Maybe we can do this differently. Take the bowling team you’re on which has a perfect team average of 300. You’ve all bowled perfectly for the entire season; every score is based on the completion of 10-frame strings. Thus, your score expectancy is 300, which is as it should be, as 300 is what every team should expect, being the maximum score any bowler can attain.

But what if one unfortunate and undeniably sad night four of your teammates suddenly committed suicide while bowling their second frames? Should you include their uncompleted strings to what your “score expectancy” is for the team?

The life expectancy for an American male born today fell a little bit, from 76.2 years to 76.1. If we add any meaning to this at all – which I don’t think we should – the solution, of course, is to find all the oldest men in the world and import them here. If we can find 1,000,000 men over 100 years old in Europe and Asia and move them to the United States, life expectancy in the United States would at least tick upwards and, if we love being irrational, we would prevent a disaster: men could again truly expect to live longer. Phew!

There is a rather unnerving road map that compares “deaths per mile” within the U.S. Interstate System. The map shows that one well-used road, I-95, the longest interstate on the east coast, has 1.24 deaths per mile. This is particularly distressing; I fear to drive that road, although I have driven on it many times – and nearly its entire length four times – and not only have I seen no deaths in 1 mile, I have seen exactly zero deaths every 1,000 miles. But if I think about this all rather simplistically, I find a solution:  If we just lengthen the highway we can make travel safer. Who will join me in saving lives? Let’s lengthen I-95 and see “deaths per mile” drop precipitously!

These highway terrors and lifespan errors remind me of the 2007 remarks of Finnish mathematician Bjarne Andresen when he wrote of the futility of determining a “global temperature.” Such an effort would be akin to “calculating the average phone number,” he said. He could have equally said it was like searching for the average verb or even the average doubt.

While suicides and overdoses are a dreadful thing, it seems absurd to add to the already absurd “life expectancy” construct those deaths caused by intentional or reckless acts. Does the “score expectancy” in academic testing really drop if some students refuse to take tests? If I expect to score 100, must I expect a lower score if – God forbid – five of my classmates hang themselves?

The whole thing is nonsense, a mere arithmetical phenomenon that is seemingly devised, in part, to get the attention of politicians and the like, meaning, those who might direct funding a certain way. If the public can be alarmed into believing that people are simply not living longer because some people jump off cliffs (many with skis on) and take horrifying risks with their bodies, abusing themselves with drugs and mortal weapons and death-challenging stunts, then the public’s fear can be turned toward their wallets. “Please give – or else,” they hear the winds of fear whisper.

And here’s something that seems perverse when seen in the inverse:  if you want to lower “life expectancy” in the United States, you could illegally traffic millions of poor, sick, neglected, harrowed “asylum-seekers” with children who are fleeing horrors unimaginable (or just low-wage jobs). Or, you could legally and mindfully manage immigration through proper ports of entry and thus possibly raise “life expectancy” to heights deemed “acceptable.” (One wonders if the CDC fully considers the impact immigration, legal or illegal, has on “life expectancy”; if we factor out immigrants – who are by definition born elsewhere – we still must deal with the disadvantaged children born here into those immigrant families. One hopes all the CDC findings have to do with when, and more importantly where, one is born. But is the CDC certain all its data are drawn from the dead who were actually born in the United States?)

But if you really want to raise a ruckus, maybe telling the world that “life expectancy” in the United States is on the decline will reduce the world’s interest in America. Maybe then folks will no longer, you know, caravan across dangerous lands to get to such a disappointing place.

In the end, all I can really do, I suppose, is to seek for the answer to this undeniably above-average question:  “What is the average statistical fallacy I can expect to commit per mile in my lifetime?”