A large population segment is necessary to prove that it works.

Demographers call the 80-plus group the "oldest old" and say it is one of the fastest-growing population segments around the world.

One problem is getting the message across to a population segment that tends to feel immortal and pretty much immune to life-threatening issues.

The population segment most likely to develop lung cancer is people aged over 50 who have a history of smoking.

In particular, he pointed to the aging of the largest population segment, the baby boom generation.

Do we really think it's okay that certain population segments just won't be able to afford to drive at certain places and times?

And the biggest population segment - the baby boomers - are in a nesting mood.

"Any other population segment could be freely sacrificed," Lepikov said.