About a third of women with children in the U.S. do not work outside the home. Many eventually will want to reenter the workforce, although doing so isn't without challenges. Perhaps the industry a woman once worked in has evolved, her skills are no longer relevant or she has fewer business connections. Even if none of those problems present themselves, there's no escaping the dreaded employment gap on a resume, though.

What to do about an employment gap?

Conventional wisdom dictates filling in a gap with activities which make it look like a person has been keeping herself sharp, such as freelance work, self-employment or volunteering.  Yet researchers at Vanderbilt University found that outright admitting to taking time off to raise children actually increases the chances a candidate will be hired.

Prospective employers don't like ambiguity.

Vanderbilt Law School economists Joni Hersch and Jennifer Bennett Shinall asked more than 3,000 subjects to pretend to be employers and choose between two potential hires who were mostly alike except in how they explained a 10-year employment gap. The subjects were given an interview scenario in which the make-believe candidates--Lisa Davis and Jessica Wilson--either failed to explain a gap or admitted to wanting to return to work because of children being in school or because of financial necessity due to divorce.

The results may surprise you: The candidate who gave personal information raised her chance of being hired by 30 to 40 percentage points, compared to the woman who did not.

Why? The authors believe it has something to do with the behavioral economics theory of ambiguity aversion. Essentially, people don't like unknown risks and any explanation for a gap is better than none.

Candidates should be proactive during an interview.

The authors note, however, that many employers will not ask a candidate about personal information such as family status out of fear of litigation. Given the results of this study, it follows then that a stay-at-home mom wanting to return to work should offer the truth about an employment gap related to child-rearing, even if not expressly asked by an employer during an interview.

The authors do not advise including personal and family information in resumes, applications, and cover letters, however. "We... worry that a woman who advertises she is pregnant in her cover letter, or who lists the births of her six children on her resume, will immediately see her application tossed by the employer, without any further consideration," they write. "What we advocate for is an increase in honest conversations at the interview stage."