The set of active controllers isn't static: people come and people go. If you raise pay right now, current, skilled controllers will be more inclined to stay, w

The set of active controllers isn't static: people come and people go. If you raise pay right now, current, skilled controllers will be more inclined to stay, while new controllers who've been training for the last 2.9 years join. Raising pay helps combat attrition, which increases the population.