Pathways vs. Pipelines to broadening participation in the stem workforce

This paper examines why women and minorities are underrepresented in science research careers. Millions of dollars of support over the years have been expended to remedy the underrepresentation of women and minorities in different science, technology, engineering, and mathematics (STEM) disciplines. An underlying premise of virtually every major intervention designed to increase the representation of women and racial and ethnic minority group members in STEM careers is that there exists a dominant pipeline toward those careers. The premise is that there is a conventional sequence of educational and training procedures for a specific career profile, and that such a sequence is effective in producing the desired results of increased representation of underrepresented groups. An alternative model—the pathways model—posits that there are multiple routes toward the required training for science careers and that the underlying problem is not the undersupply of graduates in science but barriers that undervalue these alternative routes taken by women and minorities. This paper tests the hypothesis that the pipeline metaphor is the correct representation of the production of increased diversity, using the chemistry profession as the case study. Using data from the Integrated Public Use Microdata Series–Current Population Survey (IPUMS-CPS) March Supplement for the period 1968–2012, we estimate post-baccalaureate (supply-side) effects and wage impacts (demand-side effects) on the relative presentation of women and minorities among those employed as chemists. We find large differences across racial, ethnic, and gender groups. We find very limited evidence to support the supply-side argument. The responsiveness to demand-side factors tends to be larger for minority group members than for others, suggesting that the pipeline model is inadequate for explaining underrepresentation in all professions. Finally, we show that women and minorities are underrepresented at different critical transition points from high school to college to graduate school to the workforce.