Jobs emphasizing science, technology, engineering and math (STEM) skills have long conjured up images of research universities and corporate offices.

Many such STEM-heavy jobs require a bachelor’s or advanced degree. But what’s often not talked about is the roughly equal number of STEM jobs found on factory floor shops, construction sites and other blue-collar workplaces.

A Brookings Institution study published Monday makes the case that policymakers are overlooking the role these blue-collar STEM jobs play in the economy, finding far more STEM workers than previous estimates. About 26 million jobs (20 percent of the U.S. workforce) required knowledge of at least one STEM field in 2011. About half of these jobs did not call for a four-year degree, paying an average salary of $53,000, according to the report.

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Skills for these jobs often aren’t acquired from four-year universities, but rather at community colleges, workshops and vocational schools. While professionals with advanced degrees typically do design work or make higher-level decisions, it’s the blue collar STEM workers who carry out the actual production or technical repairs when needed.

“Notwithstanding the economic importance of professional STEM workers, high-skilled blue-collar and technical STEM workers have made, and continue to make, outsized contributions to innovation,” the report states.

The report also suggests demand for these types of jobs is growing. In particular, the construction and manufacturing sector are shifting in this direction.

To examine STEM jobs across different metro areas, the study classified jobs using data from surveys part of the Labor Department’s Occupational Information Network Data Collection Program. One section of the survey asks workers to assess the level of knowledge required in different areas for their work, which Brookings then used as the basis for identifying STEM jobs.

Areas with the highest concentrations of STEM jobs aren’t too surprising. The San Jose-Sunnyvale-Santa Clara, Calif., metro area and all of its tech-heavy companies topped the list, with 33 percent of the workforce requiring high knowledge of at least one STEM field. Washington, D.C., ranked second with 27 percent.

We’ve compiled the following map using Brookings data showing STEM jobs for the 100 largest metro areas. STEM jobs accounted for the largest share of the total workforce in green regions; purple areas recorded lower percentages. (Open full-screen map in new window or click a marker to display an area's totals)

In general, jobs requiring at least a bachelor’s degree account for the majority of the STEM jobs in regions with the most such available positions. The Brookings report and other studies have also pointed out these regions, shown in green, tend to have lower unemployment.

A slightly different pattern emerges if we look only at STEM jobs not requiring a four-year degree.

By this measure, the following metro areas were shown to have the top concentrations of STEM jobs:

  • Baton Rouge, LA: 12.6% of workforce
  • Birmingham-Hoover, AL: 12.5% of workforce
  • New Orleans-Metairie-Kenner, LA: 12.4% of workforce
  • Cape Coral-Fort Myers, FL: 12.4% of workforce
  • Wichita, KS: 12.3% of workforce
Here’s another map showing only STEM jobs not requiring four-year degrees. Again, green markers represent higher percentages, while purple signifies lower figures.

View Larger Map

You’ll notice that the type of STEM jobs vary by metro area. Several of the employment hubs in northern California, for example, are more heavy on STEM jobs requiring bachelor’s degrees, while the opposite appears to be true in Florida.

View an interactive STEM jobs map
Read Brookings profiles for each metro area