The budget battles of recent years have amplified the warnings of demographic doomsayers who predicted that a wave of baby boomers would bleed America dry, bankrupting Social Security and Medicare as they faded into an impoverished old age. On the contrary, argues award-winning journalist Chris Farrell, we are instead on the verge of a broad, positive transformation of our economy and society.

The old idea of "retirement"--a word that means withdrawal, describing a time when people gave up productive employment and shrank their activities--was a short-lived historical anomaly....