Let's start today with some numbers,
some demographic statistics that I think you'll find surprising.
Here's the first one.
Within 10 years,
there will likely be more people in the US 65 and older than there are people 18 and younger.
This is a brand new state of affairs,
and the rest of the world is following the same path.
Let's call it the Elder Swell.
How can this Elder Swell be explained?
It's been driven by two big trends.
Lower fertility, which we talked about in part one of this series,
and a massive increase in life expectancy, especially over the past century and a quarter.
That is thanks to, among other things,
more abundant food, cleaner air and water, less war,
and vastly better public health and medical care,
especially the treatment and prevention of diseases that used to kill so many children.
But the real headline of The Elder's Swell is not just that more people will be living more years,
it's that those years are expected to be better.
This is what researchers call healthspan versus lifespan.
Let me give you another set of surprising statistics.