Historic first: Older adults now outnumber the youngest children worldwide

People 65 and older now outnumber children ages 5 and younger worldwide for the first time in recorded history, according to a new report by the U.S. Census.

Why it matters: A global plunge in fertility — demographers' term for the number of children being born — and increased longevity are creating a demographic inversion that's projected to deepen for decades.

It's a trend that's shifting the historic balance between working-age people and older adults.