Manufactured scarcity

The most common answer among writers who take the problem seriously, and the most revealing. Material scarcity ends; within a generation, something else is scarce instead — reputation, subjective time, standing, access.

This is worth reading as a confession. If you believe abundance solves the problem, you do not need this plot device. Every author who reaches for it is conceding that the bottleneck was never resources. It was ranking: the need to be someone whose effort was necessary, which requires that effort be able to fail.

The invented scarcities are strikingly arbitrary — the right to run a theme park ride, a running clock, an exercise-bike credit balance. That arbitrariness is the point. Any measure will do, provided it can run out.