Pipers, Droppers, Nevers, and Hoppers: Observed Career Pathways Among STEM Ph.D. Scientists

Abstract

This paper investigates the appropriateness of the pipeline metaphor and its appropriateness to the careers of individuals with Ph.D.s in a science, technology, engineering, or math (STEM) discipline. Using longitudinal data that follows the first 7-9 years of post-conferral employment among scientists who attained their degree in the U.S. between 2000-2008. We examine all STEM Ph.D.s in our sample as well as each specific discipline. In our primary analysis, we examine the share of careers that fit into pipeline-defined trajectories: on the tenure track (pipers), left the tenure track (droppers), never entered tenure track (nevers), and those who “hop” from outside academia into academia (hoppers). We find that a traditional pipeline path into a tenure track position describes a minority of career trajectories; the majority of Ph.D. scientist never work in academia. Further, a large share of tenure-track faculty “hop” into their position, meaning that they were in a non-tenure-track job before a tenure-track position, a career path not possible within the pipeline framework. We use two alternative methods yielding similar results: the pipeline metaphor is not useful for most careers, and we propose, not accurate. We offer an alternative conceptualization—the STEM lattice—and discuss how a lattice offers more opportunity for identifying policy intervention for increasing underrepresented minorities in STEM.