What Makes Job Seekers Lie on Their Resumes?The reason behind a fraudulent resume? Try envy.

The next time you come across a resume that's too good to be true, add a couple of extra items to the "abilities" segment: envy and immorality.

Experts say people who lie on their CVs are likely to have been unemployed for a long time and appear to be motivated by jealousy for other people who have landed jobs when they haven't.

"Envy was one of the things we found that really mattered," said Michelle Duffy, a professor of work and organizations at the University of Minnesota, and the co-author of a paper on resume fraud.

Resume fakers are also worth catching, because the researchers found that those who are comfortable exaggerating their skills also are more comfortable being immoral in other ways.

Take the case of ex-trader Mathew Martoma, the SAC Capital Advisers employee who was convicted Thursday of conspiracy and securities fraud charges. Years before the trading scandal, court transcripts revealed that he had been expelled from Harvard after forging a Harvard transcript to submit for a clerkship.

"If you hire somebody who's misrepresented their resume, not only might you get somebody who has lesser qualifications but you might get somebody who's likely to steal from the organization or commit other types of fraud," said Brian Dineen, an associate professor management at Purdue University who also co-wrote the paper on fraud.

"If you hire somebody who has misrepresented their resume, not only might you get somebody who has lesser qualifications but ... somebody who's likely to steal from the organization or commit other types of fraud," said Brian Dineen, an associate professor management at Purdue University and a co-author of the paper.

The researchers found that people who lied didn't necessarily start out intending to embellish or fake their credentials. But the longer they were unemployed with no job in sight, the more tempting it became.

Dineen likens it to sticking to that New Year's resolution: During the first week of January it was probably pretty easy to get to the gym and avoid the chocolate box, but by mid-February it's harder to be so virtuous.

"Job seekers will channel their envy toward greater effort early on," Dineen said. "But then later on they will channel their envy toward resume fraud."

It's not clear how often people embroider or fabricate parts of their resume. A survey of hiring managers released by CareerBuilder in 2008 found thatnearly half of thosesurveyed had caught someone lying at some point. Less than 10 percent of workers surveyed admitted to lying.

A CareerBuilder survey from 2012 found that nearlythree in 10 hiring managerssurveyed had caught someone using a fake reference.

Sherry Dixon, senior vice president with the staffing firm Adecco, said that though she has seen a rise in the number of people intentionally lying on a resume in the past three to five years, it's still a small minority.

People are more likely to exaggerate some aspect of their experience, such as their contribution to a particular project, than to fake a credential, such as a diploma.

Technology has made it easier to check credentials, Dixon said, but it also has made it easier to fake them. People can create websites for fictitious companies and buy credentials from Internet-based "diploma mills."

Often, she said, candidates have been telling the lie for so long that it can be tough to catch until the company starts verifying education, checking references and running a background check.

"They're good," Dixon said.

There are plenty of high-profile cases of people who have paid a price for resume fraud. Perhaps the most famous case isFrank Abagnale, who pretended to be everything from a pilot to a pediatrician. His life story was made famous by the book and film "Catch Me If You Can."

More recently, many people were outraged when thesign language interpreterat Nelson Mandela's memorial turned out to be an imposter who made unintelligible gestures.

Despite the high-profile cases, people who embellished their resumes seemed to think it was acceptable--reasoning that people do it all the time and that there was a low likelihood of exposure, according to the University of Minnesota's Duffy.

They may not feel too bad about it, either.

Duffy said her previous research has shown that people feel all right about bad behavior at work as long as they don't get caught.

"People tend not to feel guilty if they get away with it and are successful," she said.