Iowa employers are reporting trouble filling jobs requiring education in science, technology, engineering and math, while the state's average pay for high-tech positions is 15 percent below the national average, federal statistics show.

But analyzing Iowa's pay gap in what is known as the STEM fields is complicated, economists say. For example, Iowa's average STEM salary of $75,730 can be offset by Iowa's relatively low cost of living compared with some other states, which can have higher expenses for housing, food, commuting, personal services and state and local taxes. The national average for STEM salaries is $89,400.

Other factors also contribute to Iowa's difficulty filling STEM-related jobs, which include occupations such as mechanical engineers, chemists, animal scientists, software developers and computer user support specialists.

These reasons range from the fact that Iowa doesn't have a Silicon Valley, which offers a wealth of high-tech firms with well-paying jobs, to the state's chilly winters and lack of natural amenities to attract and retain college-educated millennials, some experts say.

Brian Waller, president of the 300-member Technology Association of Iowa, said a shortage of high-tech workers is an issue in every state. So he isn't surprised to hear of STEM job vacancies in Iowa.

He believes that below-average salaries in Iowa for high-tech jobs don't cause workers to leave this state. But smaller paychecks do raise issues when trying to lure Iowa natives to return home to seek employment.

"If you are a tech person working in Chicago or San Francisco,and there is this really great opportunity with a company in Iowa, you are going to look at the price point of salary. If you take it at face value, you are going to going say, 'Well, that is a pay cut,'" Waller said. "But if you look under quality of life and cost of living, and some of those things like commute times, you are actually probably making more money than you did in those bigger markets. But the fact that we have to explain that is probably a little bit of an impediment, yes.”

Gov. Kim Reynolds and Iowa business leaders have pointed to 12,400 job vacancies in STEM occupations while expressing their support for an emphasis by educators in science, technology, engineering and math, beginning in elementary school and continuing through high school and college.

The unfilled jobs are cited in a new report issued by the Governor's STEM Advisory Council, although state officials use a much broader definition of STEM jobs than federal officials. The state's consideration adds occupations such as health care workers and welders, plumbers and some other blue-collar trades. State officials say STEM jobs represent 17 percent of Iowa's workforce, while the U.S. Bureau of Labor Statistics says 4.7 percent of Iowans work in STEM jobs, compared with 6.3 percent nationally.

Reynolds describes STEM education as a way for young Iowans to launch a career that offers a good paycheck while bolstering the state's economy.

“It is really an important part of our overall workforce strategy in Iowa," Reynolds told reporters recently, citing projections for significant growth of STEM jobs in Iowa. "This is absolutely the way that we are going to stay innovative and competitive, not only as a state, but as a country. And that really represents unlimited opportunities for young people and unlimited opportunities for them to stay here in Iowa."

Nationally, Iowa has received some good marks in reports and rankings of high-tech states and cities. Investopedia, a financial news and education website, listed Des Moines as one of its five hottest "start-up cities" in 2015. Smart Asset, a New York-based personal technology firm, placed Des Moines and Cedar Rapids in 2016 on its top 10 ranking of best cities for tech workers. NerdWallet, a personal finance website, listed five cities in Iowa on its list of best places for STEM graduates in 2016.

There are vast contrasts in pay in Iowa between jobs requiring backgrounds in science, technology, engineering and mathematics versus pay for other occupations, federal statistics show. Iowa's average pay of $75,730 for STEM occupations using the federal definition compares to an average pay of $41,920 for non-STEM employment, a difference of 44.6 percent.

But Iowa State University labor economist Peter Orazen said he's a little skeptical of the claim that Iowa is falling short in filling STEM-related jobs by 12,400 people.

"At some point, you have to ask, 'Are you actually willing to pay what it takes somebody to take this job?'" Orazem asked. "Maybe some of the definitions of whom you want to hire are more pipe-dream than reality."

However, Orazem agreed with other economists who suggest the fact that Iowa's pay falls below the national median for STEM jobs reflects differentials in costs of living compared with other places. He noted there are similar differences in Iowa incomes for other types of jobs when compared with national trends.

Thomas McDonald, a senior economist with the Bureau of Labor Statistics in Chicago, said Iowa's lower average pay for STEM jobs can be seen as a positive factor by some companies looking to establish high-tech businesses in Iowa.

"You say, 'Where do I want to set up shop?' Well, if you have a viable pool of people in Iowa, and if I can have the same quality of workforce and pay slightly less, maybe that is the place I want to look," McDonald said.

But Orazem said one of Iowa's difficulties is a lack of a liquid employment market compared with some tech-rich cities on the West Coast and other areas. His daughter-in-law, for example, is a computer engineer in Seattle who worked at five or six different companies in high-tech jobs there early in her career.

"That doesn't mean firms here couldn't raise their salaries and improve things, but at the end of the day, my sense is that it is not salaries that are the real sticking point," Orazem added. "It is that you don't have a Silicon Valley full of potential employers where, if you don't like where you are currently working, you can just go next door and knock."

Creighton University economist Ernie Goss said the 15 percent average wage gap,, coupled with a lack of natural amenities available in places such as Colorado and California, makes it more difficult for Iowa businesses to recruit young professionals for high-tech jobs. He believes those are also reasons why graduates of the University of Iowa, Iowa State University and the University of Northern Iowa sometimes leave this state.

If Iowa millennials graduating in STEM fields want to find higher pay, they are likely to head to places such as San Jose, California, Austin, Texas; North Carolina's Research Triangle or Boston, Goss said. Those are hotbeds for research and development early in the life cycle of high tech and manufacturing and offer more high-paid job opportunities.

Goss noted that when ConAgra Brands, an $8 billion food company, stunned Omaha community leaders two years ago by announcing a move of its corporate headquarters to Chicago, analysts cited workforce availability as one reason for the shift and commented that Omaha couldn't compete with Chicago in the minds of many millennials.

But Waller of the Iowa Technology Association is optimistic about the future for high-tech jobs in Iowa. His organization is encouraging a focus on diversity and inclusion to prompt more women and minorities to enter the field. He also wants students to learn how to become creators of technology, and not just high-tech consumers.

"In a lot of industries in Iowa, we are creating great technology solutions," Waller said, including Principal Financial Group, Wellmark Blue Cross and Blue Shield, Hy-Vee, Kum & Go, and Fareway Stores.

"There are great technology jobs that are out there. There are fun industries that you get to work in. And part of our job is to showcase that."

Average pay for STEM jobs*

UNITED STATES: $89,400

IOWA: $75,730

MINNESOTA: $86,760

ILLINOIS: $86,510

MISSOURI: $79,480

SOUTH DAKOTA: $66,280

WISCONSIN: $73,930

KANSAS: $75,790

CALIFORNIA: $103,830

Average STEM pay in metro areas

DES MOINES-WEST DES MOINES: $82,280

AMES: $77,010

IOWA CITY: $71,040

CEDAR RAPIDS: $84,010

DAVENPORT/MOLINE/ROCK ISLAND: $77,890

DUBUQUE: $68,700

WATERLOO-CEDAR FALLS: $71,790

OMAHA-COUNCIL BLUFFS: $77,910

CHICAGO: $88,270

KANSAS CITY: $81,490

MINNEAPOLIS-ST. PAUL: $89,690

SAN JOSE-SUNNYVALE-SANTA CLARA: $126,240

*STEM-related jobs require backgrounds in science, engineering, technology and mathematics. The federal definition of STEM jobs used for this salary survey includes a wide range of occupations, such as software developers, database administrators, architects, aerospace engineers, and animal scientists. But the federal definition does not include health care workers and blue-collar trades and certain other occupations used in a broader definition by the State of Iowa.

Source: U.S Bureau of Labor Statistics, May 2016 report.