Any mention of STEM (Science, Technology, Engineering, Mathematics) evokes images of engineers fiddling with sophisticated machinery or research scientists peering into microscopes.
But a new study argues that you don't need a Ph.D., or even a bachelor's degree, to be part of the STEM economy.
The report issued Monday by the Brookings Institution contends that any job that requires specialized knowledge in STEM areas - including health care, manufacturing and construction trades - could be considered a STEM job.
That means the STEM economy is far deeper than previously imagined, said Jonathan Rothwell, an associate fellow at Washington, D.C.-based Brookings who authored the study.
While previous estimates have pegged STEM employment at 4 to 5 percent of total workers, STEM employment under Brookings' expanded definition is about 20 percent of all jobs nationally, and slightly higher in the Tucson area.
"There's actually a whole diverse array of occupations that require STEM knowledge," Rothwell said.
Rothwell said he and his colleagues originally set out to study the STEM economy. But they quickly realized that the usual definition of STEM left out many workers whose jobs require deep knowledge in one or more STEM fields.
While there is no uniform definition of "STEM," the term's origins have been traced to use by the National Science Foundation starting in the early 2000s (early on, the agency apparently used the less-elegant acronym "SMET").
The NSF definition - used in guidelines for scholarships and grants - is fairly broad, including areas like education and social and economic sciences in addition to the obvious categories like the biological sciences, engineering and computer sciences.
But the definition leaves out many technical jobs - notably including many health-care professionals (the NSF supports fundamental science and engineering but not "medical science").
"It's not just the engineers and scientists, it's also the health-care workers, particularly doctors and nurses and lab technicians," Rothwell said.
Beyond health care, the Brookings report found that non-degreed jobs requiring significant STEM knowledge include many nonprofessional jobs in manufacturing, health care, construction and mining.
In individual analysis of 100 metropolitan areas, Tucson ranked higher than average in the proportion of STEM jobs to overall employment in 2011, with a 20.3 percent STEM job share in the area and a rank of 42nd among surveyed metro areas.
The Phoenix metro area had a somewhat smaller proportion of STEM jobs, 19.9 percent. It ranked 54th among the metro areas studied, according to the Brookings report.
Brookings' Rothwell said many STEM jobs requiring less than a college education go begging.
"There is evidence to suggest that demand has outstripped supply for some of these technical blue-collar and otherwise sub-bachelor STEM jobs," Rothwell said.
Recognizing shortages or looming worker shortfalls in certain key local industries, the Pima County Workforce Reinvestment Board recently adopted a sector strategy to tailor educational and training programs to specific local needs.
For example, a new local industry internship program was recently launched to address a shortfall particularly in operators of computerized machining equipment.
Gregg Johnson, Tucson campus director of the University of Phoenix and chairman of the county Workforce Investment Board, said technology has become a major part of many occupations, from machining to logistics.
"A lot of those jobs, they're going to have some STEM education coming in," Johnson said. "And a lot of the best jobs are STEM-related."
Community colleges can play an important role in training STEM workers, but they receive far less funding from federal, state and local governments than research universities, Brookings' Rothwell said.
"It's worth taking another look at the role of community colleges, because they are not only bringing up workers through the community-college system and into four-year programs, but they are also preparing students immediately for jobs in the STEM economy," he said.
Alex Rodriguez, Southern Arizona director of the Arizona Technology Council, said the Brookings report confirms what he hears from the group's members: More needs to be done to educate and train workers, particularly for non-degreed technical jobs.
"Clearly, the age of the knowledge worker has arrived," Rodriguez said. "It's a race for talent in the new economy, and I'm not surprised (by the report) in light of what I see in our growing technology companies in Southern Arizona."
Rodriguez said he views the Brookings report as a "clarion call" for policymakers to boost support for community colleges and programs like the Joint Technical Education District, which offers high school students vocational training in technical fields.
View the report
To view or download the report "The Hidden STEM Economy," go to the Brookings Institution website at brookings.edu or for a direct link go to tinyurl.com/ker2mhq
By the numbers
Average annual wages for all STEM jobs in Tucson area
Average annual wages for Tucson-area STEM jobs requiring an associate's degree or less
Average annual wages for non-STEM jobs requiring associate's degree or less
STEM jobs in the Tucson metro area, 2011
Percentage of STEM jobs in Tucson area
Source: Brookings Institution
Contact Assistant Business Editor David Wichner at email@example.com or 573-4181.