Abstract for: PhDs in queue and the US science workforce trajectory

Persistent career challenges for early-career scientists in the United States are contributing to bottlenecks in the scientific workforce pipeline. Limited tenure-track positions, combined with a growing influx of doctorate recipients, have resulted in a long queue of PhDs waiting in temporary and lower-paid postdoctoral roles. This study develops a simulation model to analyze the dynamics of the US science workforce, focusing on the flow of PhD graduates into academia. The model is tested against data from 2003 to 2023 and spans four major fields: engineering, biological and biomedical sciences, physical sciences, and social sciences. The study evaluates the long-term impacts of current and proposed policies on workforce trajectories. Simulation results demonstrate significant variations across fields. Policies such as shortening PhD durations, expanding postdoctoral funding, or increasing faculty positions can paradoxically extend the queue for newly graduated PhDs. On the other hand, strategies like reducing PhD admissions, promoting early transitions to industry, and increasing faculty retirement rates prove effective in alleviating the backlog. The findings highlight the complexity of the academic workforce ecosystem and the unintended consequences of well-intentioned policies. The study calls for systemic and comprehensive policy interventions to create sustainable and viable career paths for early-career scientists in the US.