The U.S. has a remarkable track record of innovation and continues to lead the world in the development of many new technologies. Why, then, isn't the nation's science-and-engineering work force -- the people responsible for much of that innovation -- growing?

That's a question posed by the Population Reference Bureau's recent analysis of the science-and-engineering (S&E) workforce. As a percentage of the total labor force, S&E workers accounted for 4.9% of the workforce in 2010, a slight decline from the three previous years when these workers accounted for 5% of the workforce.

That percentage has been essentially flat for the past decade. In 2000, it stood at 5.3%.

Science-and-engineering workforce as a percent of U.S. workforce. (Chart by Population Reference Bureau.)

Ideally, the S&E workforce -- it numbers more than 7.6 million workers -- would be expanding as a percentage of the labor force. That would mean U.S. companies are increasing their use of S&E workers.

There's no clear explanation for this trend, either anecdotally or in the Bureau's data. Take IBM. In the same week it announced a breakthrough in quantum computing, it laid off more than 1,400 workers. How many of those workers were in science and engineering is unknown, but IBM has steadily cut the number of employees in the U.S. as it expands in other countries.

I-Ling Shen, a senior research analyst and economist at the Milken Institute, looked at the PRB data and said there could be "a lot of explanations" for its findings. The data may indicate either a supply or demand problem for S&E workers, or it could be signaling a shift in the composition of the workforce, she said.

Regarding demand, wages for these workers have increased relative entire the workforce. If there had been a lack of demand, wages would have gone done, said Shen.

There are possibilities other than wages that may explain the flattening of the S&E workforce. The PRB's data, which comes from the U.S. Census, defines S&E workers broadly, and includes those in labor-intensive jobs without advanced degrees who may have been replaced by automation, said Shen.

Another factor may be retirements. S&E workers who are 55 and older accounted for 13% of this workforce in 2005; they accounted for 18% in 2010. "This might imply that there aren't enough young people entering the S&E labor force - and I really thought this might be a key issue," said Shen.

Mark Mather, an associate vice president at PRB and a report author, said the decline may reflect job losses in high-end manufacturing. "I don't think it's good news if you got declines in fields that tend be higher paying and require more skills and higher levels of education -- I don't think it's a good sign," he said.

The data might not mean there is an outright shortage of S&E workers; it could indicate a combination of factors related to such things as the recession and offshoring. "I wouldn't call it a positive development, but I didn't want to paint it as a negative picture either, because I don't know if it's going to last," said Mather.

The U.S. government believes that more S&E workers are needed and President Barack Obama last year called on the government to produce 10,000 more engineers a year.

Electicial engineering employment and wages. (Chart by Milken Institute, based on U.S. labor data.)

Patrick Thibodeau covers cloud computing and enterprise applications, outsourcing, government IT policies, data centers and IT workforce issues for Computerworld. Follow Patrick on Twitter at @DCgov or subscribe to Patrick's RSS feed . His e-mail address is pthibodeau@computerworld.com.

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