Philippe Weis: For a few to be immortal, many must die.
Will Salas: Wrong!
Raymond Leon: I don't have time. I don't have time to worry about how it happened. It is what it is. We're genetically engineered to stop aging at 25. The trouble is, we live only one more year, unless we can get more time. Time is now the currency. We earn it and spend it. The rich can live forever. And the rest of us? I just want to wake up with more time on my hand than hours in the day.
Sylvia Weis: I didn't mean to shoot him, I wanted to scare him.
Will Salas: I think you did both.
Will Salas: Don't worry he'll give up before we do.
[Gunshot richoches off wall nearby.]
Sylvia Weis: You sure about that?
Will Salas: No. (01:15:55)
Chosen answer: When they turn 25, their built-in clock starts counting down from 1 year. Since time is the currency, they must then work and contribute to the economy, in order to earn time and survive. The government gives that one year of time to each person, as both a population control measure (if they don't work and earn, they'll die) and an economic incentive.
David R Turner