Thank you Philip Bump for this perfectly illustrated explanation of the question of life expectancy which I have tried to explain to people to no avail. For some reason this concept seems to be hard for some people to accept:
One day recently, three old friends met to play pickleball. Alan, 85, had taken up the sport first. Over time, he compelled his old college acquaintances Bob, 80, and Don, 75, to join him, in keeping with the rapidly growing sport’s slow downward trend in the median age of its participants.
On this day, though, Bob was preoccupied.
“Does it ever bother you guys,” he asked, as they were warming up, “that each of us is above the average life expectancy in the U.S.?” Bob, you see, was well-versed in government data, in part thanks to his willingness to indulge in the natural human inclination to want to understand and explore numbers.
And Bob was right. The most recent estimates compiled by the Centers for Disease Control and Prevention, for the year 2021, put American life expectancy at just over 76 years of age. That varies by race, with Asian Americans being estimated to live more than 83 years and Black Americans just under 71 years.
“I think about this a lot!” interjected Don. “Especially since men have even shorter life expectancies, regardless of age.” Don was not known as being particularly attentive to such intricacies, surprising his companions. But he’d spent an enormous amount of time over the prior 12 months considering the subject, as he believed that it was important for his plans.
And, again, this was correct. White men, like Don, had a life expectancy of just over 73 years in 2021. Among Black men, like Alan, the expectancy was under 67 years.
“You’re lucky,” replied Bob, who’d grown increasingly agitated. “You live in Florida, where life expectancies were slightly higher than the national figure in 2020. I live in Delaware, where life expectancies are even lower.” (If you are curious why Don and Bob were playing pickleball with Alan despite living in different states, it is because each of them had ready access to private aircraft for different reasons.)
“Well, that’s true,” Alan replied, joining the conversation at a useful pivot point. “But that’s because expectancy correlates to income, which correlates to race.”
“But regardless, you guys are completely missing the point,” he continued, now getting warmed up. (He was used to having to get Bob and Don to have to understand the bigger picture.) “What you’re talking about is life expectancy at birth, which isn’t what is important for us.”
Bob and Don looked at each other in confusion. Alan sighed.
“Think of it this way,” Alan continued. “Imagine there’s a houseplant that consistently lives for precisely 10 years. But there’s one exception: for the first year after it sprouts, 1 in 5 plants will suddenly die for inexplicable reasons.”
“So this plant lives an average of a bit over 8 years,” he said. “let’s just call that the life expectancy for the sake of the example. Once you’re past that first year, though? All of the plants will live to 10 years.”
“So a three-year-old plant has a life expectancy of 10 years?” Bob asked.
“No,” Alan replied. It has a life expectancy of seven years — seven more years.” Bob and Don looked at each other and nodded.
“That’s how the government publishes life expectancy data,” Alan said. “Americans born in 2021 were expected to live 76.1 years. But Americans who were 75 were expected to live 11.5 more years — to 86.5. And since people keep living past their life expectancies, the expectancy keeps going up over time.”
“What do you mean?” Don asked.
“Well, think of it this way,” Alan said. “A lot of people who were 75 in 2021 will live past 11 more years, past the age of 86. We need to recalculate life expectancies for those people — and it obviously has to be higher than 86!”
Alan grabbed his phone and pulled up the CDC data. No one objected; data is more interesting than pickleball.
“As ages increase, so do life expectancies,” Alan said, showing them a graph he found in a newsletter he subscribes to. “And, over time, the racial disparities in life expectancy mostly fade. Expectancies converge.”
The graph, well-designed and clear, made this obvious. For example, Black Americans have died younger than other groups for decades. Once Black Americans live to old age, though, their life expectancies match other groups.
“In fact,” Alan said, zooming in on the graph, “by the age of 85, Black Americans have higher life expectancies than Whites, even just among men. But its subtle.”
For Bob, though, something else about the graph leaped out at him.
“Wait,” he said, pointing at the chart. “This suggests that, according to 2021 estimates, I’d be expected to live nearly another eight years after I turned 80.”
“That’s right,” Alan replied. “And that’s with those 2021 estimates, reflecting the height of the pandemic. It’s expected that the new estimates will show life expectancies moving back up after multiple years of declines.”
“Oh, that’s a relief,” Bob said. “I’d been thinking about making a long-term, four-year commitment next year but was wondering whether that made sense, given that I’d be 86 when it ends. I guess I should have more confidence in my ability to fulfill that commitment than I assumed.”
Alan nodded. Bob looked relieved. Don, though, seemed irritated for some reason. And so ends our allegory.