The population of people doing science is increasingly older, and fewer young people are establishing careers in the field. A recent paper published in PNAS finds there are two main factors contributing to the aging STEM workforce (science, tech, engineering, and math). The first is that a large majority of current scientists come from the baby boomer generation—now ages 50 to 70. The second main contributor is that in 1994, universities eliminated mandatory retirement, so many older scientists continue to work long past traditional retirement ages.

This trend could have severe consequences, as science may end up lacking the diverse perspectives needed for creative solutions, and there will be fewer qualified individuals to step up when the boomers finally do retire.

An aging cohort

The authors of this PNAS paper use data from the National Science Foundation and the US Survey of Doctorate Recipients to examine age-related demographic trends in STEM PhD recipients. Between 1993 and 2010, the authors saw a decline in scientists ages 35 to 53 and a rise in scientists older than 53. This shift reflects the aging of people currently working in STEM fields rather than a change in the population of researchers.

Additionally, when they compared the STEM workforce to the general workforce, the authors saw that the STEM workforce—older to start with—is aging more rapidly. Between 1993 and 2010, the average age of the scientific workforce increased from 45.1 to 48.6, whereas the average age of the general workforce only increased from 42.2 to 45.4.

The authors also examined the share of the workforce that is older than 55. Between 1993 and 2010, the fraction of the general workforce over 55 years old rose from 0.15 to 0.23. By comparison, for the STEM fields, the share of the workforce over 55 increased from 0.18 in 1993 to 0.33 in 2010, a much more marked increase.

The authors next looked for a breakdown of workers’ ages by their research specialty, figuring some fields might have bigger problems than others. But an excessively aging workforce turned out to be pervasive throughout the sciences. However, scientists who focus primarily on research or who work in academia do tend to be slightly younger than those who work in industry, though the overall trends are still very similar.

Multiple causes

In addition to the demographic trends related to the baby boomers aging, the authors looked at other possible influences on the age distribution in STEM fields. One major determinant is the age at which new scientists receive their PhDs. For example, in the 1970s, scientists tended to be 30 when they received their PhD, but by 1993, the average age at completion of doctoral work had risen to 33.

One thing that wasn't a factor is the immigration of PhD recipients from other countries to the US. The authors found that foreign-born and US-born PhD researchers have similar employment patterns.

Perhaps the biggest determinant of the age distribution in STEM fields is the rate at which people exit the scientific workforce—in that they're not. The authors saw that in 1993, there was a large spike in retirement among scientists at age 70. However, this spike had disappeared by the year 2008, largely due to changes in university policies regarding mandatory retirement. Before 1994, universities had been excluded from the 1986 Age Discrimination Act and were permitted to dictate retirement ages for employees. However, by the late 1990s and early 2000s, universities were no longer exempt from this law, which resulted in more scientists choosing to remain at work after age 70.

The significance of these findings for the development of STEM fields depends in part on the scientific productivity of older scientists versus younger scientists. If productivity and creativity are lower at older ages, then we've got problems. However, forcing all older scientists to retire and make room for a new cohort of researchers is also clearly not the answer, since older researchers retain highly valuable knowledge and experience of the field. It's also likely that a diverse mix of experienced scientists and younger ones who are more likely to explore and adopt new technologies would be more productive.

Faced with this challenge of an aging STEM workforce, somehow employers must find a way to make room for new recruits while maintaining the spaces held by current researchers. In the current funding environment for academic science, this charge is already challenging, and it's likely to get much worse.

PNAS, 2017. DOI: 10.1073/pnas.1611748114 (About DOIs)