According to this Chronicle of Higher Education article, women and underrepresented minorities seem to be more discouraged about academic careers and are seeking professional development opportunities outside of academic research.
“I realized that a large part of my work would be tied to securing a very limited amount of funding and not mentoring students or thinking about research problems,” says Ms. Poston. She was also discouraged by how long it generally takes for scientific research to be put to use, she says. “I proactively sought out professional-development opportunities that would expose me to career pathways that were outside of academic research.”
Plenty of graduate students in the sciences may feel this way, but women and underrepresented minorities, who tend to find the academic environment less supportive, seem to feel it more acutely. That means it will probably take more than a robust pipeline of prospective scientists to increase the diversity of STEM disciplines.