Via numerical experiments, we show that the $sim$10%-20% passive fraction seen at $z>3$ is consistent with galaxy star formation histories being maximally correlated stochastic processes. If so, this fraction should reflect a time-independent baseline that holds at any epoch or mass regime where mean star formation rates are rising. Data at $log M_ast<10$ and $z<0.5$ bear this out, as should future James Webb Space Telescope observations.
Download