An interesting perspective on life expectancy

As part of a longer article on US health care in the latest Daily Dispatch newsletter from Casey Research, the authors provide some interesting insights into how US life expectancy has increased, and why.  Here's an excerpt from the (much longer) article.

Are We Really Living That Much Longer?

It is easy to dismiss the days of people's lives spanning a mere three decades as prehistoric. But it wasn't really that long ago. Consider that according to data compiled by the World Health Organization, the average global lifespan as recently as the year 1900 was just that, 30 years. In the richest few countries on Earth at the time, the number rarely crossed 50.

However, it was just about that time that public health came into its own, with major efforts from both the private and public sectors. In 1913, the Rockefeller Foundation was "looking for diseases that might be controlled or perhaps even eradicated in the space of a few years or a couple of decades … Technical approaches also tended to yield immediately quantifiable results that justified equivalent expenditure of funds."

The result of this concerted public-health push included nearly eradicating smallpox, leprosy, and other debilitating or deadly diseases. It also included vaccines against the six killer diseases of childhood: tetanus, polio, measles, diphtheria, tuberculosis, and whooping cough.

A simple graph illustrates the dramatic change.

In the US, the average lifespan is now 78.2 years, according to the World Bank. In many countries in the world it is well over 80. But the story isn't so simple. Like all averages, it's affected mainly by the extremes. And in the early part of the 1900s, the data point that weighed most heavily on average lifespans was child mortality. Not the least of the reasons why families were much larger then is that parents routinely expected some of their children to die.

But the flip side, as can be seen in the graph, is that for anyone lucky enough to survive childhood at the turn of the last century, life expectancy was not that much lower than it is today. For all of our advances in medicine, we only live about 20 to 30% longer. Not only is the increase quite small – relative, say, to the explosion in computing power over the same period of time – the amount of money we spend adding another year or two to the average lifespan is on the rise. In other words, each additional day we live costs more than the one before it. And, as with compound interest, the effect is amplified over time.

In essence, we have picked much of the low-hanging fruit from the tree of life.

So if, absent high child mortality, we are not living all that much longer today than we once were, where does all the money we spend watering that tree actually go?

We can get a glimpse of the answer in the following graph. Intuitively, one would think that there should be a relationship between the economic wellbeing of a country and the life expectancy of its citizens. And, as you would imagine, there is a strong correlation between wealth and health.

The important takeaway from this graph is the flattening of the curve along the top. What it means is that many countries with lower GDPs (and, consequently, less to spend on health care) can attain life expectancies in the 65-75 range. Pushing them higher than that, as the richer countries do, clearly requires much greater resources. By implication, that means spending more to do it.

The cost of battling the diseases of adulthood rises dramatically with age.

How much so? Well, per capita lifetime healthcare expenditure in the US is $316,600, a third higher for females ($361,200) than males ($268,700). But two-fifths of this difference owes entirely to women's longer life expectancy. For everyone, nearly one-third of lifetime expenditures is incurred during middle age, and nearly half during the senior years. And for survivors to age 85, more than one-third of their lifetime expenditures will accrue in just the years they have left.

There's more at the link.  Interesting and recommended reading.

Peter