Getty Images/iStockphoto

When Americans buy a home, they compare the prices of similar houses in the same area. But when it comes to securing a new job, many may fail to do their research and end up leaving money on the table.

The typical worker is earning about $7,500 less per year, or about 13.3 percent, than they should be, according to new research from employment site Glassdoor, which analyzed pay data from 1.3 million U.S. employees. The jobs with the biggest gaps in what employees actually earn versus what they could make tend to be in the most in-demand sectors: health care, tech and finance.

Despite a growing economy, many American workers have suffered from stagnant and slow-growing wages, a disparity that has puzzled economists. Some have pointed to the decline of organized labor as a culprit, but workers may also be hampered by a lack of transparency. Data on what others in your field are earning can help workers negotiate higher salaries, although many Americans accept the first offer from a prospective employer.

"It's like owning a home: People look at the value of their home based on local indicators," said Glassdoor community expert Scott Dobroski. "With pay, people aren't doing that. We do it with our homes, but not with ourselves."

More than two-thirds of women don't negotiate salary when they take a new job, compared with about one-half of men, he added (Employees can benchmark their pay using Glassdoor's Know Your Worth tool.)

"For some reason, men are much more comfortable negotiating their salaries," he said. "This is a takeaway for all employees. Knowing your current market value is irrespective of gender and ethnicity."

Employees working in tech, health care and finance may be in the best position to negotiate for higher salaries, simply because demand is so high to fill jobs. It's important to back up why you believe you should be paid more, Dobroski said. Looking for a job elsewhere can help workers find better-paying roles.

"If you are making a job decision based only on pay, that's not enough," he added.

Other issues to consider are include benefits, the mission of the company and career advancement potential.

Read on to learn about the nine most underpaid jobs in America.